summaryrefslogtreecommitdiffstats
path: root/core/modules/file/file.module
blob: 47b72ef1665561bc5d1f73b64867fbb8b769cab4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
<?php

/**
 * @file
 * Defines a "managed_file" Form API field and a "file" field for Field module.
 */

use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Render\Element;
use Drupal\file\Entity\File;
use Drupal\Component\Utility\NestedArray;
use Drupal\Component\Utility\Unicode;
use Drupal\Core\Entity\EntityStorageInterface;
use Drupal\Core\Template\Attribute;
use Drupal\file\FileUsage\FileUsageInterface;
use Symfony\Component\HttpFoundation\Request;

// Load all Field module hooks for File.
require_once __DIR__ . '/file.field.inc';

/**
 * Implements hook_help().
 */
function file_help($route_name, Request $request) {
  switch ($route_name) {
    case 'help.page.file':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('The File module allows you to create fields that contain files. See the <a href="!field">Field module help</a> and the <a href="!field_ui">Field UI help</a> pages for general information on fields and how to create and manage them. For more information, see the <a href="!file_documentation">online documentation for the File module</a>.', array('!field' => \Drupal::url('help.page', array('name' => 'field')), '!field_ui' => \Drupal::url('help.page', array('name' => 'field_ui')), '!file_documentation' => 'https://drupal.org/documentation/modules/file')) . '</p>';
      $output .= '<h3>' . t('Uses') . '</h3>';
      $output .= '<dl>';
      $output .= '<dt>' . t('Managing and displaying file fields') . '</dt>';
      $output .= '<dd>' . t('The <em>settings</em> and the <em>display</em> of the file field can be configured separately. See the <a href="!field_ui">Field UI help</a> for more information on how to manage fields and their display.', array('!field_ui' => \Drupal::url('help.page', array('name' => 'field_ui')))) . '</dd>';
      $output .= '<dt>' . t('Allowing file extensions') . '</dt>';
      $output .= '<dd>' . t('In the field settings, you can define the allowed file extensions (for example <em>pdf docx psd</em>) for the files that will be uploaded with the file field.') . '</dd>';
      $output .= '<dt>' . t('Storing files ') . '</dt>';
      $output .= '<dd>' . t('Uploaded files can either be stored as <em>public</em> or <em>private</em>, depending on the <a href="!file-system">File system settings</a>. For more information, see the <a href="!system-help">System module help page</a>.', array('!file-system' => \Drupal::url('system.file_system_settings'), '!system-help' => \Drupal::url('help.page', array('name' => 'system')))) . '</dd>';
      $output .= '<dt>' . t('Restricting the maximum file size') . '</dt>';
      $output .= '<dd>' . t('The maximum file size that users can upload is limited by PHP settings of the server, but you can restrict by entering the desired value as the <em>Maximum upload size</em> setting. The maximum file size is automatically displayed to users in the help text of the file field.') . '</dd>';
      $output .= '<dt>' . t('Displaying files and descriptions') . '<dt>';
      $output .= '<dd>' . t('In the field settings, you can allow users to toggle whether individual files are displayed. In the display settings, you can then choose one of the following formats: <ul><li><em>Generic file</em> displays links to the files and adds icons that symbolize the file extensions. If <em>descriptions</em> are enabled and have been submitted, then the description is displayed instead of the file name.</li><li><em>URL to file</em> displays the full path to the file as plain text.</li><li><em>Table of files</em> lists links to the files and the file sizes in a table.</li><li><em>RSS enclosure</em> only displays the first file, and only in a RSS feed, formatted according to the RSS 2.0 syntax for enclosures.</li></ul> A file can still be linked to directly by its URI even if it is not displayed.') . '</dd>';
      $output .= '</dl>';
      return $output;
  }
}

/**
 * Implements hook_element_info().
 *
 * The managed file element may be used anywhere in Drupal.
 */
function file_element_info() {
  $types['managed_file'] = array(
    '#input' => TRUE,
    '#process' => array('file_managed_file_process'),
    '#value_callback' => 'file_managed_file_value',
    '#element_validate' => array('file_managed_file_validate'),
    '#pre_render' => array('file_managed_file_pre_render'),
    '#theme' => 'file_managed_file',
    '#theme_wrappers' => array('form_element'),
    '#progress_indicator' => 'throbber',
    '#progress_message' => NULL,
    '#upload_validators' => array(),
    '#upload_location' => NULL,
    '#size' => 22,
    '#multiple' => FALSE,
    '#extended' => FALSE,
    '#attached' => array(
      'library' => array('file/drupal.file'),
    ),
  );
  return $types;
}

/**
 * Loads file entities from the database.
 *
 * @param array $fids
 *   (optional) An array of entity IDs. If omitted, all entities are loaded.
 * @param $reset
 *   Whether to reset the internal file_load_multiple() cache.
 *
 * @return array
 *   An array of file entities, indexed by fid.
 *
 * @deprecated in Drupal 8.x, will be removed before Drupal 9.0.
 *   Use \Drupal\file\Entity\File::loadMultiple().
 *
 * @see hook_file_load()
 * @see file_load()
 * @see entity_load()
 * @see \Drupal\Core\Entity\Query\EntityQueryInterface
 */
function file_load_multiple(array $fids = NULL, $reset = FALSE) {
  if ($reset) {
    \Drupal::entityManager()->getStorage('file')->resetCache($fids);
  }
  return File::loadMultiple($fids);
}

/**
 * Loads a single file entity from the database.
 *
 * @param $fid
 *   A file ID.
 * @param $reset
 *   Whether to reset the internal file_load_multiple() cache.
 *
 * @return \Drupal\file\FileInterface
 *   A file entity or NULL if the file was not found.
 *
 * @deprecated in Drupal 8.x, will be removed before Drupal 9.0.
 *   Use \Drupal\file\Entity\File::load().
 *
 * @see hook_file_load()
 * @see file_load_multiple()
 */
function file_load($fid, $reset = FALSE) {
  if ($reset) {
    \Drupal::entityManager()->getStorage('file')->resetCache(array($fid));
  }
  return File::load($fid);
}

/**
 * Returns the file usage service.
 *
 * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
 *   Use \Drupal::service('file.usage').
 *
 * @return \Drupal\file\FileUsage\FileUsageInterface.
 */
function file_usage() {
  return \Drupal::service('file.usage');
}

/**
 * Copies a file to a new location and adds a file record to the database.
 *
 * This function should be used when manipulating files that have records
 * stored in the database. This is a powerful function that in many ways
 * performs like an advanced version of copy().
 * - Checks if $source and $destination are valid and readable/writable.
 * - If file already exists in $destination either the call will error out,
 *   replace the file or rename the file based on the $replace parameter.
 * - If the $source and $destination are equal, the behavior depends on the
 *   $replace parameter. FILE_EXISTS_REPLACE will error out. FILE_EXISTS_RENAME
 *   will rename the file until the $destination is unique.
 * - Adds the new file to the files database. If the source file is a
 *   temporary file, the resulting file will also be a temporary file. See
 *   file_save_upload() for details on temporary files.
 *
 * @param \Drupal\file\File $source
 *   A file entity.
 * @param $destination
 *   A string containing the destination that $source should be copied to.
 *   This must be a stream wrapper URI.
 * @param $replace
 *   Replace behavior when the destination file already exists:
 *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
 *       the destination name exists then its database entry will be updated. If
 *       no database entry is found then a new one will be created.
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
 *       unique.
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
 *
 * @return
 *   File object if the copy is successful, or FALSE in the event of an error.
 *
 * @see file_unmanaged_copy()
 * @see hook_file_copy()
 */
function file_copy(File $source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
  if (!file_valid_uri($destination)) {
    if (($realpath = drupal_realpath($source->getFileUri())) !== FALSE) {
      watchdog('file', 'File %file (%realpath) could not be copied because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', array('%file' => $source->getFileUri(), '%realpath' => $realpath, '%destination' => $destination));
    }
    else {
      watchdog('file', 'File %file could not be copied because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', array('%file' => $source->getFileUri(), '%destination' => $destination));
    }
    drupal_set_message(t('The specified file %file could not be copied because the destination is invalid. More information is available in the system log.', array('%file' => $source->getFileUri())), 'error');
    return FALSE;
  }

  if ($uri = file_unmanaged_copy($source->getFileUri(), $destination, $replace)) {
    $file = $source->createDuplicate();
    $file->setFileUri($uri);
    $file->setFilename(drupal_basename($uri));
    // If we are replacing an existing file re-use its database record.
    // @todo Do not create a new entity in order to update it, see
    //   https://drupal.org/node/2241865
    if ($replace == FILE_EXISTS_REPLACE) {
      $existing_files = entity_load_multiple_by_properties('file', array('uri' => $uri));
      if (count($existing_files)) {
        $existing = reset($existing_files);
        $file->fid = $existing->id();
        $file->setOriginalId($existing->id());
        $file->setFilename($existing->getFilename());
      }
    }
    // If we are renaming around an existing file (rather than a directory),
    // use its basename for the filename.
    elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
      $file->setFilename(drupal_basename($destination));
    }

    $file->save();

    // Inform modules that the file has been copied.
    \Drupal::moduleHandler()->invokeAll('file_copy', array($file, $source));

    return $file;
  }
  return FALSE;
}

/**
 * Moves a file to a new location and update the file's database entry.
 *
 * Moving a file is performed by copying the file to the new location and then
 * deleting the original.
 * - Checks if $source and $destination are valid and readable/writable.
 * - Performs a file move if $source is not equal to $destination.
 * - If file already exists in $destination either the call will error out,
 *   replace the file or rename the file based on the $replace parameter.
 * - Adds the new file to the files database.
 *
 * @param \Drupal\file\File $source
 *   A file entity.
 * @param $destination
 *   A string containing the destination that $source should be moved to.
 *   This must be a stream wrapper URI.
 * @param $replace
 *   Replace behavior when the destination file already exists:
 *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
 *       the destination name exists then its database entry will be updated and
 *       $source->delete() called after invoking hook_file_move().
 *       If no database entry is found then the source files record will be
 *       updated.
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
 *       unique.
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
 *
 * @return \Drupal\file\File
 *   Resulting file entity for success, or FALSE in the event of an error.
 *
 * @see file_unmanaged_move()
 * @see hook_file_move()
 */
function file_move(File $source, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
  if (!file_valid_uri($destination)) {
    if (($realpath = drupal_realpath($source->getFileUri())) !== FALSE) {
      watchdog('file', 'File %file (%realpath) could not be moved because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', array('%file' => $source->getFileUri(), '%realpath' => $realpath, '%destination' => $destination));
    }
    else {
      watchdog('file', 'File %file could not be moved because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', array('%file' => $source->getFileUri(), '%destination' => $destination));
    }
    drupal_set_message(t('The specified file %file could not be moved because the destination is invalid. More information is available in the system log.', array('%file' => $source->getFileUri())), 'error');
    return FALSE;
  }

  if ($uri = file_unmanaged_move($source->getFileUri(), $destination, $replace)) {
    $delete_source = FALSE;

    $file = clone $source;
    $file->setFileUri($uri);
    // If we are replacing an existing file re-use its database record.
    if ($replace == FILE_EXISTS_REPLACE) {
      $existing_files = entity_load_multiple_by_properties('file', array('uri' => $uri));
      if (count($existing_files)) {
        $existing = reset($existing_files);
        $delete_source = TRUE;
        $file->fid = $existing->id();
        $file->uuid = $existing->uuid();
      }
    }
    // If we are renaming around an existing file (rather than a directory),
    // use its basename for the filename.
    elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
      $file->setFilename(drupal_basename($destination));
    }

    $file->save();

    // Inform modules that the file has been moved.
    \Drupal::moduleHandler()->invokeAll('file_move', array($file, $source));

    // Delete the original if it's not in use elsewhere.
    if ($delete_source && !\Drupal::service('file.usage')->listUsage($source)) {
      $source->delete();
    }

    return $file;
  }
  return FALSE;
}

/**
 * Checks that a file meets the criteria specified by the validators.
 *
 * After executing the validator callbacks specified hook_file_validate() will
 * also be called to allow other modules to report errors about the file.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 * @param $validators
 *   An optional, associative array of callback functions used to validate the
 *   file. The keys are function names and the values arrays of callback
 *   parameters which will be passed in after the file entity. The
 *   functions should return an array of error messages; an empty array
 *   indicates that the file passed validation. The functions will be called in
 *   the order specified.
 *
 * @return
 *   An array containing validation error messages.
 *
 * @see hook_file_validate()
 */
function file_validate(File $file, $validators = array()) {
  // Call the validation functions specified by this function's caller.
  $errors = array();
  foreach ($validators as $function => $args) {
    if (function_exists($function)) {
      array_unshift($args, $file);
      $errors = array_merge($errors, call_user_func_array($function, $args));
    }
  }

  // Let other modules perform validation on the new file.
  return array_merge($errors, \Drupal::moduleHandler()->invokeAll('file_validate', array($file)));
}

/**
 * Checks for files with names longer than can be stored in the database.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 *
 * @return
 *   An array. If the file name is too long, it will contain an error message.
 */
function file_validate_name_length(File $file) {
  $errors = array();

  if (!$file->getFilename()) {
    $errors[] = t("The file's name is empty. Please give a name to the file.");
  }
  if (strlen($file->getFilename()) > 240) {
    $errors[] = t("The file's name exceeds the 240 characters limit. Please rename the file and try again.");
  }
  return $errors;
}

/**
 * Checks that the filename ends with an allowed extension.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 * @param $extensions
 *   A string with a space separated list of allowed extensions.
 *
 * @return
 *   An array. If the file extension is not allowed, it will contain an error
 *   message.
 *
 * @see hook_file_validate()
 */
function file_validate_extensions(File $file, $extensions) {
  $errors = array();

  $regex = '/\.(' . preg_replace('/ +/', '|', preg_quote($extensions)) . ')$/i';
  if (!preg_match($regex, $file->getFilename())) {
    $errors[] = t('Only files with the following extensions are allowed: %files-allowed.', array('%files-allowed' => $extensions));
  }
  return $errors;
}

/**
 * Checks that the file's size is below certain limits.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 * @param $file_limit
 *   An integer specifying the maximum file size in bytes. Zero indicates that
 *   no limit should be enforced.
 * @param $user_limit
 *   An integer specifying the maximum number of bytes the user is allowed.
 *   Zero indicates that no limit should be enforced.
 *
 * @return
 *   An array. If the file size exceeds limits, it will contain an error
 *   message.
 *
 * @see hook_file_validate()
 */
function file_validate_size(File $file, $file_limit = 0, $user_limit = 0) {
  $user = \Drupal::currentUser();
  $errors = array();

  if ($file_limit && $file->getSize() > $file_limit) {
    $errors[] = t('The file is %filesize exceeding the maximum file size of %maxsize.', array('%filesize' => format_size($file->getSize()), '%maxsize' => format_size($file_limit)));
  }

  // Save a query by only calling spaceUsed() when a limit is provided.
  if ($user_limit && (\Drupal::entityManager()->getStorage('file')->spaceUsed($user->id()) + $file->getSize()) > $user_limit) {
    $errors[] = t('The file is %filesize which would exceed your disk quota of %quota.', array('%filesize' => format_size($file->getSize()), '%quota' => format_size($user_limit)));
  }

  return $errors;
}

/**
 * Checks that the file is recognized by Image::getInfo() as an image.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 *
 * @return
 *   An array. If the file is not an image, it will contain an error message.
 *
 * @see hook_file_validate()
 */
function file_validate_is_image(File $file) {
  $errors = array();

  $image = \Drupal::service('image.factory')->get($file->getFileUri());
  if (!$image->isSupported()) {
    $extensions = array();
    foreach ($image->getToolkit()->supportedTypes() as $image_type) {
      $extensions[] = Unicode::strtoupper(image_type_to_extension($image_type));
    }
    $errors[] = t('Image type not supported. Allowed types: @types.', array('@types' => implode(', ', $extensions)));
  }

  return $errors;
}

/**
 * Verifies that image dimensions are within the specified maximum and minimum.
 *
 * Non-image files will be ignored. If a image toolkit is available the image
 * will be scaled to fit within the desired maximum dimensions.
 *
 * @param \Drupal\file\File $file
 *   A file entity. This function may resize the file affecting its size.
 * @param $maximum_dimensions
 *   An optional string in the form WIDTHxHEIGHT e.g. '640x480' or '85x85'. If
 *   an image toolkit is installed the image will be resized down to these
 *   dimensions. A value of 0 indicates no restriction on size, so resizing
 *   will be attempted.
 * @param $minimum_dimensions
 *   An optional string in the form WIDTHxHEIGHT. This will check that the
 *   image meets a minimum size. A value of 0 indicates no restriction.
 *
 * @return
 *   An array. If the file is an image and did not meet the requirements, it
 *   will contain an error message.
 *
 * @see hook_file_validate()
 */
function file_validate_image_resolution(File $file, $maximum_dimensions = 0, $minimum_dimensions = 0) {
  $errors = array();

  // Check first that the file is an image.
  $image_factory = \Drupal::service('image.factory');
  $image = $image_factory->get($file->getFileUri());
  if ($image->isSupported()) {
    if ($maximum_dimensions) {
      // Check that it is smaller than the given dimensions.
      list($width, $height) = explode('x', $maximum_dimensions);
      if ($image->getWidth() > $width || $image->getHeight() > $height) {
        // Try to resize the image to fit the dimensions.
        $image = $image_factory->get($file->getFileUri());
        if ($image->isExisting()) {
          $image->scale($width, $height);
          $image->save();
          $file->filesize = $image->getFileSize();
          drupal_set_message(t('The image was resized to fit within the maximum allowed dimensions of %dimensions pixels.', array('%dimensions' => $maximum_dimensions)));
        }
        else {
          $errors[] = t('The image is too large; the maximum dimensions are %dimensions pixels.', array('%dimensions' => $maximum_dimensions));
        }
      }
    }

    if ($minimum_dimensions) {
      // Check that it is larger than the given dimensions.
      list($width, $height) = explode('x', $minimum_dimensions);
      if ($image->getWidth() < $width || $image->getHeight() < $height) {
        $errors[] = t('The image is too small; the minimum dimensions are %dimensions pixels.', array('%dimensions' => $minimum_dimensions));
      }
    }
  }

  return $errors;
}

/**
 * Saves a file to the specified destination and creates a database entry.
 *
 * @param $data
 *   A string containing the contents of the file.
 * @param $destination
 *   A string containing the destination URI. This must be a stream wrapper URI.
 *   If no value is provided, a randomized name will be generated and the file
 *   will be saved using Drupal's default files scheme, usually "public://".
 * @param $replace
 *   Replace behavior when the destination file already exists:
 *   - FILE_EXISTS_REPLACE - Replace the existing file. If a managed file with
 *       the destination name exists then its database entry will be updated. If
 *       no database entry is found then a new one will be created.
 *   - FILE_EXISTS_RENAME - Append _{incrementing number} until the filename is
 *       unique.
 *   - FILE_EXISTS_ERROR - Do nothing and return FALSE.
 *
 * @return \Drupal\file\FileInterface
 *   A file entity, or FALSE on error.
 *
 * @see file_unmanaged_save_data()
 */
function file_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAME) {
  $user = \Drupal::currentUser();

  if (empty($destination)) {
    $destination = file_default_scheme() . '://';
  }
  if (!file_valid_uri($destination)) {
    watchdog('file', 'The data could not be saved because the destination %destination is invalid. This may be caused by improper use of file_save_data() or a missing stream wrapper.', array('%destination' => $destination));
    drupal_set_message(t('The data could not be saved because the destination is invalid. More information is available in the system log.'), 'error');
    return FALSE;
  }

  if ($uri = file_unmanaged_save_data($data, $destination, $replace)) {
    // Create a file entity.
    $file = entity_create('file', array(
      'uri' => $uri,
      'uid' => $user->id(),
      'status' => FILE_STATUS_PERMANENT,
    ));
    // If we are replacing an existing file re-use its database record.
    // @todo Do not create a new entity in order to update it, see
    //   https://drupal.org/node/2241865
    if ($replace == FILE_EXISTS_REPLACE) {
      $existing_files = entity_load_multiple_by_properties('file', array('uri' => $uri));
      if (count($existing_files)) {
        $existing = reset($existing_files);
        $file->fid = $existing->id();
        $file->setOriginalId($existing->id());
        $file->setFilename($existing->getFilename());
      }
    }
    // If we are renaming around an existing file (rather than a directory),
    // use its basename for the filename.
    elseif ($replace == FILE_EXISTS_RENAME && is_file($destination)) {
      $file->setFilename(drupal_basename($destination));
    }

    $file->save();
    return $file;
  }
  return FALSE;
}

/**
 * Examines a file entity and returns appropriate content headers for download.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 *
 * @return
 *   An associative array of headers, as expected by
 *   \Symfony\Component\HttpFoundation\StreamedResponse.
 */
function file_get_content_headers(File $file) {
  $type = mime_header_encode($file->getMimeType());

  return array(
    'Content-Type' => $type,
    'Content-Length' => $file->getSize(),
    'Cache-Control' => 'private',
  );
}

/**
 * Implements hook_theme().
 */
function file_theme() {
  return array(
    // file.module.
    'file_link' => array(
      'variables' => array('file' => NULL, 'icon_directory' => NULL, 'description' => NULL, 'attributes' => array()),
    ),
    'file_icon' => array(
      'variables' => array('file' => NULL, 'icon_directory' => NULL),
    ),
    'file_managed_file' => array(
      'render element' => 'element',
    ),

    // file.field.inc.
    'file_widget' => array(
      'render element' => 'element',
    ),
    'file_widget_multiple' => array(
      'render element' => 'element',
    ),
    'file_formatter_table' => array(
      'variables' => array('items' => NULL),
    ),
    'file_upload_help' => array(
      'variables' => array('description' => NULL, 'upload_validators' => NULL, 'cardinality' => NULL),
    ),
  );
}

/**
 * Implements hook_file_download().
 *
 * This function takes an extra parameter $field_type so that it may
 * be re-used by other File-like modules, such as Image.
 */
function file_file_download($uri, $field_type = 'file') {
  $user = \Drupal::currentUser();

  // Get the file record based on the URI. If not in the database just return.
  /** @var \Drupal\file\FileInterface[] $files */
  $files = entity_load_multiple_by_properties('file', array('uri' => $uri));
  if (count($files)) {
    foreach ($files as $item) {
      // Since some database servers sometimes use a case-insensitive comparison
      // by default, double check that the filename is an exact match.
      if ($item->getFileUri() === $uri) {
        $file = $item;
        break;
      }
    }
  }
  if (!isset($file)) {
    return;
  }

  // Find out which (if any) fields of this type contain the file.
  $references = file_get_file_references($file, NULL, EntityStorageInterface::FIELD_LOAD_CURRENT, $field_type);

  // Stop processing if there are no references in order to avoid returning
  // headers for files controlled by other modules. Make an exception for
  // temporary files where the host entity has not yet been saved (for example,
  // an image preview on a node/add form) in which case, allow download by the
  // file's owner.
  if (empty($references) && ($file->isPermanent() || $file->getOwnerId() != $user->id())) {
    return;
  }

  // Default to allow access.
  $denied = FALSE;
  // Loop through all references of this file. If a reference explicitly allows
  // access to the field to which this file belongs, no further checks are done
  // and download access is granted. If a reference denies access, eventually
  // existing additional references are checked. If all references were checked
  // and no reference denied access, access is granted as well. If at least one
  // reference denied access, access is denied.
  foreach ($references as $field_name => $field_references) {
    foreach ($field_references as $entity_type => $entities) {
      $field_storage_definitions = \Drupal::entityManager()->getFieldStorageDefinitions($entity_type);
      $field = $field_storage_definitions[$field_name];
      foreach ($entities as $entity) {
        // Check if access to this field is not disallowed.
        if (!$entity->get($field_name)->access('view')) {
          $denied = TRUE;
          continue;
        }

        // Invoke hook and collect grants/denies for download access.
        // Default to FALSE and let entities overrule this ruling.
        $grants = array('system' => FALSE);
        foreach (\Drupal::moduleHandler()->getImplementations('file_download_access') as $module) {
          $grants = array_merge($grants, array($module => \Drupal::moduleHandler()->invoke($module, 'file_download_access', array($field, $entity, $file))));
        }
        // Allow other modules to alter the returned grants/denies.
        $context = array(
          'entity' => $entity,
          'field' => $field,
          'file' => $file,
        );
        \Drupal::moduleHandler()->alter('file_download_access', $grants, $context);

        if (in_array(TRUE, $grants)) {
          // If TRUE is returned, access is granted and no further checks are
          // necessary.
          $denied = FALSE;
          break 3;
        }

        if (in_array(FALSE, $grants)) {
          // If an implementation returns FALSE, access to this entity is denied
          // but the file could belong to another entity to which the user might
          // have access. Continue with these.
          $denied = TRUE;
        }
      }
    }
  }

  // Access specifically denied.
  if ($denied) {
    return -1;
  }

  // Access is granted.
  $headers = file_get_content_headers($file);
  return $headers;
}

/**
 * Implements file_cron()
 */
function file_cron() {
  $age = \Drupal::config('system.file')->get('temporary_maximum_age');

  // Only delete temporary files if older than $age. Note that automatic cleanup
  // is disabled if $age set to 0.
  if ($age) {
    $fids = Drupal::entityQuery('file')
      ->condition('status', FILE_STATUS_PERMANENT, '<>')
      ->condition('changed', REQUEST_TIME - $age, '<')
      ->range(0, 100)
      ->execute();
    $files = file_load_multiple($fids);
    foreach ($files as $file) {
      $references = \Drupal::service('file.usage')->listUsage($file);
      if (empty($references)) {
        if (file_exists($file->getFileUri())) {
          $file->delete();
        }
        else {
          watchdog('file system', 'Could not delete temporary file "%path" during garbage collection', array('%path' => $file->getFileUri()), WATCHDOG_ERROR);
        }
      }
      else {
        watchdog('file system', 'Did not delete temporary file "%path" during garbage collection because it is in use by the following modules: %modules.', array('%path' => $file->getFileUri(), '%modules' => implode(', ', array_keys($references))), WATCHDOG_INFO);
      }
    }
  }
}

/**
 * Saves file uploads to a new location.
 *
 * The files will be added to the {file_managed} table as temporary files.
 * Temporary files are periodically cleaned. Use the 'file.usage' service to
 * register the usage of the file which will automatically mark it as permanent.
 *
 * @param $form_field_name
 *   A string that is the associative array key of the upload form element in
 *   the form array.
 * @param array $form_state
 *   An associative array containing the current state of the form.
 * @param $validators
 *   An optional, associative array of callback functions used to validate the
 *   file. See file_validate() for a full discussion of the array format.
 *   If no extension validator is provided it will default to a limited safe
 *   list of extensions which is as follows: "jpg jpeg gif png txt
 *   doc xls pdf ppt pps odt ods odp". To allow all extensions you must
 *   explicitly set the 'file_validate_extensions' validator to an empty array
 *   (Beware: this is not safe and should only be allowed for trusted users, if
 *   at all).
 * @param $destination
 *   A string containing the URI that the file should be copied to. This must
 *   be a stream wrapper URI. If this value is omitted, Drupal's temporary
 *   files scheme will be used ("temporary://").
 * @param $delta
 *   Delta of the file to save or NULL to save all files. Defaults to NULL.
 * @param $replace
 *   Replace behavior when the destination file already exists:
 *   - FILE_EXISTS_REPLACE: Replace the existing file.
 *   - FILE_EXISTS_RENAME: Append _{incrementing number} until the filename is
 *     unique.
 *   - FILE_EXISTS_ERROR: Do nothing and return FALSE.
 *
 * @return
 *   Function returns array of files or a single file object if $delta
 *   != NULL. Each file object contains the file information if the
 *   upload succeeded or FALSE in the event of an error. Function
 *   returns NULL if no file was uploaded.
 *
 *   The documentation for the "File interface" group, which you can find under
 *   Related topics, or the header at the top of this file, documents the
 *   components of a file entity. In addition to the standard components,
 *   this function adds:
 *   - source: Path to the file before it is moved.
 *   - destination: Path to the file after it is moved (same as 'uri').
 */
function file_save_upload($form_field_name, $validators = array(), $destination = FALSE, $delta = NULL, $replace = FILE_EXISTS_RENAME) {
  $user = \Drupal::currentUser();
  static $upload_cache;

  $file_upload = \Drupal::request()->files->get("files[$form_field_name]", NULL, TRUE);
  // Make sure there's an upload to process.
  if (empty($file_upload)) {
    return NULL;
  }

  // Return cached objects without processing since the file will have
  // already been processed and the paths in $_FILES will be invalid.
  if (isset($upload_cache[$form_field_name])) {
    if (isset($delta)) {
      return $upload_cache[$form_field_name][$delta];
    }
    return $upload_cache[$form_field_name];
  }

  // Prepare uploaded files info. Representation is slightly different
  // for multiple uploads and we fix that here.
  $uploaded_files = $file_upload;
  if (!is_array($file_upload)) {
    $uploaded_files = array($file_upload);
  }

  $files = array();
  foreach ($uploaded_files as $i => $file_info) {
    // Check for file upload errors and return FALSE for this file if a lower
    // level system error occurred. For a complete list of errors:
    // See http://php.net/manual/features.file-upload.errors.php.
    switch ($file_info->getError()) {
      case UPLOAD_ERR_INI_SIZE:
      case UPLOAD_ERR_FORM_SIZE:
        drupal_set_message(t('The file %file could not be saved because it exceeds %maxsize, the maximum allowed size for uploads.', array('%file' => $file_info->getFilename(), '%maxsize' => format_size(file_upload_max_size()))), 'error');
        $files[$i] = FALSE;
        continue;

      case UPLOAD_ERR_PARTIAL:
      case UPLOAD_ERR_NO_FILE:
        drupal_set_message(t('The file %file could not be saved because the upload did not complete.', array('%file' => $file_info->getFilename())), 'error');
        $files[$i] = FALSE;
        continue;

      case UPLOAD_ERR_OK:
        // Final check that this is a valid upload, if it isn't, use the
        // default error handler.
        if (is_uploaded_file($file_info->getRealPath())) {
          break;
        }

        // Unknown error
      default:
        drupal_set_message(t('The file %file could not be saved. An unknown error has occurred.', array('%file' => $file_info->getFilename())), 'error');
        $files[$i] = FALSE;
        continue;

    }
    // Begin building file entity.
    $values = array(
      'uid' => $user->id(),
      'status' => 0,
      'filename' => $file_info->getClientOriginalName(),
      'uri' => $file_info->getRealPath(),
      'filesize' => $file_info->getSize(),
    );
    $values['filemime'] = file_get_mimetype($values['filename']);
    $file = entity_create('file', $values);

    $extensions = '';
    if (isset($validators['file_validate_extensions'])) {
      if (isset($validators['file_validate_extensions'][0])) {
        // Build the list of non-munged extensions if the caller provided them.
        $extensions = $validators['file_validate_extensions'][0];
      }
      else {
        // If 'file_validate_extensions' is set and the list is empty then the
        // caller wants to allow any extension. In this case we have to remove the
        // validator or else it will reject all extensions.
        unset($validators['file_validate_extensions']);
      }
    }
    else {
      // No validator was provided, so add one using the default list.
      // Build a default non-munged safe list for file_munge_filename().
      $extensions = 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp';
      $validators['file_validate_extensions'] = array();
      $validators['file_validate_extensions'][0] = $extensions;
    }

    if (!empty($extensions)) {
      // Munge the filename to protect against possible malicious extension
      // hiding within an unknown file type (ie: filename.html.foo).
      $file->setFilename(file_munge_filename($file->getFilename(), $extensions));
    }

    // Rename potentially executable files, to help prevent exploits (i.e. will
    // rename filename.php.foo and filename.php to filename.php.foo.txt and
    // filename.php.txt, respectively). Don't rename if 'allow_insecure_uploads'
    // evaluates to TRUE.
    if (!\Drupal::config('system.file')->get('allow_insecure_uploads') && preg_match('/\.(php|pl|py|cgi|asp|js)(\.|$)/i', $file->getFilename()) && (substr($file->getFilename(), -4) != '.txt')) {
      $file->setMimeType('text/plain');
      // The destination filename will also later be used to create the URI.
      $file->setFilename($file->getFilename() . '.txt');
      // The .txt extension may not be in the allowed list of extensions. We have
      // to add it here or else the file upload will fail.
      if (!empty($extensions)) {
        $validators['file_validate_extensions'][0] .= ' txt';
        drupal_set_message(t('For security reasons, your upload has been renamed to %filename.', array('%filename' => $file->getFilename())));
      }
    }

    // If the destination is not provided, use the temporary directory.
    if (empty($destination)) {
      $destination = 'temporary://';
    }

    // Assert that the destination contains a valid stream.
    $destination_scheme = file_uri_scheme($destination);
    if (!file_stream_wrapper_valid_scheme($destination_scheme)) {
      drupal_set_message(t('The file could not be uploaded because the destination %destination is invalid.', array('%destination' => $destination)), 'error');
      $files[$i] = FALSE;
      continue;
    }

    $file->source = $form_field_name;
    // A file URI may already have a trailing slash or look like "public://".
    if (substr($destination, -1) != '/') {
      $destination .= '/';
    }
    $file->destination = file_destination($destination . $file->getFilename(), $replace);
    // If file_destination() returns FALSE then $replace === FILE_EXISTS_ERROR and
    // there's an existing file so we need to bail.
    if ($file->destination === FALSE) {
      drupal_set_message(t('The file %source could not be uploaded because a file by that name already exists in the destination %directory.', array('%source' => $form_field_name, '%directory' => $destination)), 'error');
      $files[$i] = FALSE;
      continue;
    }

    // Add in our check of the the file name length.
    $validators['file_validate_name_length'] = array();

    // Call the validation functions specified by this function's caller.
    $errors = file_validate($file, $validators);

    // Check for errors.
    if (!empty($errors)) {
      $message = t('The specified file %name could not be uploaded.', array('%name' => $file->getFilename()));
      if (count($errors) > 1) {
        $item_list = array(
          '#theme' => 'item_list',
          '#items' => $errors,
        );
        $message .= drupal_render($item_list);
      }
      else {
        $message .= ' ' . array_pop($errors);
      }
      drupal_set_message($message, 'error');
      $files[$i] = FALSE;
      continue;
    }

    // Move uploaded files from PHP's upload_tmp_dir to Drupal's temporary
    // directory. This overcomes open_basedir restrictions for future file
    // operations.
    $file->uri = $file->destination;
    if (!drupal_move_uploaded_file($file_info->getRealPath(), $file->getFileUri())) {
      drupal_set_message(t('File upload error. Could not move uploaded file.'), 'error');
      watchdog('file', 'Upload error. Could not move uploaded file %file to destination %destination.', array('%file' => $file->filename, '%destination' => $file->uri));
      $files[$i] = FALSE;
      continue;
    }

    // Set the permissions on the new file.
    drupal_chmod($file->getFileUri());

    // If we are replacing an existing file re-use its database record.
    // @todo Do not create a new entity in order to update it, see
    //   https://drupal.org/node/2241865
    if ($replace == FILE_EXISTS_REPLACE) {
      $existing_files = entity_load_multiple_by_properties('file', array('uri' => $file->getFileUri()));
      if (count($existing_files)) {
        $existing = reset($existing_files);
        $file->fid = $existing->id();
        $file->setOriginalId($existing->id());
      }
    }

    // If we made it this far it's safe to record this file in the database.
    $file->save();
    $files[$i] = $file;
  }

  // Add files to the cache.
  $upload_cache[$form_field_name] = $files;

  return isset($delta) ? $files[$delta] : $files;
}

/**
 * Determines the preferred upload progress implementation.
 *
 * @return
 *   A string indicating which upload progress system is available. Either "apc"
 *   or "uploadprogress". If neither are available, returns FALSE.
 */
function file_progress_implementation() {
  static $implementation;
  if (!isset($implementation)) {
    $implementation = FALSE;

    // We prefer the PECL extension uploadprogress because it supports multiple
    // simultaneous uploads. APC only supports one at a time.
    if (extension_loaded('uploadprogress')) {
      $implementation = 'uploadprogress';
    }
    elseif (extension_loaded('apc') && ini_get('apc.rfc1867')) {
      $implementation = 'apc';
    }
  }
  return $implementation;
}

/**
 * Implements hook_file_predelete().
 */
function file_file_predelete(File $file) {
  // TODO: Remove references to a file that is in-use.
}

/**
 * Implements hook_tokens().
 */
function file_tokens($type, $tokens, array $data = array(), array $options = array()) {
  $token_service = \Drupal::token();

  $url_options = array('absolute' => TRUE);
  if (isset($options['langcode'])) {
    $url_options['language'] = language_load($options['langcode']);
    $langcode = $options['langcode'];
  }
  else {
    $langcode = NULL;
  }
  $sanitize = !empty($options['sanitize']);

  $replacements = array();

  if ($type == 'file' && !empty($data['file'])) {
    /** @var \Drupal\file\FileInterface $file */
    $file = $data['file'];

    foreach ($tokens as $name => $original) {
      switch ($name) {
        // Basic keys and values.
        case 'fid':
          $replacements[$original] = $file->id();
          break;

        // Essential file data
        case 'name':
          $replacements[$original] = $sanitize ? check_plain($file->getFilename()) : $file->getFilename();
          break;

        case 'path':
          $replacements[$original] = $sanitize ? check_plain($file->getFileUri()) : $file->getFileUri();
          break;

        case 'mime':
          $replacements[$original] = $sanitize ? check_plain($file->getMimeType()) : $file->getMimeType();
          break;

        case 'size':
          $replacements[$original] = format_size($file->getSize());
          break;

        case 'url':
          $replacements[$original] = $sanitize ? check_plain(file_create_url($file->getFileUri())) : file_create_url($file->getFileUri());
          break;

        // These tokens are default variations on the chained tokens handled below.
        case 'created':
          $replacements[$original] = format_date($file->getCreatedTime(), 'medium', '', NULL, $langcode);
          break;

        case 'changed':
          $replacements[$original] = format_date($file->getChangedTime(), 'medium', '', NULL, $langcode);
          break;

        case 'owner':
          $name = $file->getOwner()->label();
          $replacements[$original] = $sanitize ? check_plain($name) : $name;
          break;
      }
    }

    if ($date_tokens = $token_service->findWithPrefix($tokens, 'created')) {
      $replacements += $token_service->generate('date', $date_tokens, array('date' => $file->getCreatedTime()), $options);
    }

    if ($date_tokens = $token_service->findWithPrefix($tokens, 'changed')) {
      $replacements += $token_service->generate('date', $date_tokens, array('date' => $file->getChangedTime()), $options);
    }

    if (($owner_tokens = $token_service->findWithPrefix($tokens, 'owner')) && $file->getOwner()) {
      $replacements += $token_service->generate('user', $owner_tokens, array('user' => $file->getOwner()), $options);
    }
  }

  return $replacements;
}

/**
 * Implements hook_token_info().
 */
function file_token_info() {
  $types['file'] = array(
    'name' => t("Files"),
    'description' => t("Tokens related to uploaded files."),
    'needs-data' => 'file',
  );

  // File related tokens.
  $file['fid'] = array(
    'name' => t("File ID"),
    'description' => t("The unique ID of the uploaded file."),
  );
  $file['name'] = array(
    'name' => t("File name"),
    'description' => t("The name of the file on disk."),
  );
  $file['path'] = array(
    'name' => t("Path"),
    'description' => t("The location of the file relative to Drupal root."),
  );
  $file['mime'] = array(
    'name' => t("MIME type"),
    'description' => t("The MIME type of the file."),
  );
  $file['size'] = array(
    'name' => t("File size"),
    'description' => t("The size of the file."),
  );
  $file['url'] = array(
    'name' => t("URL"),
    'description' => t("The web-accessible URL for the file."),
  );
  $file['created'] = array(
    'name' => t("Created"),
    'description' => t("The date the file created."),
    'type' => 'date',
  );
  $file['changed'] = array(
    'name' => t("Changed"),
    'description' => t("The date the file was most recently changed."),
    'type' => 'date',
  );
  $file['owner'] = array(
    'name' => t("Owner"),
    'description' => t("The user who originally uploaded the file."),
    'type' => 'user',
  );

  return array(
    'types' => $types,
    'tokens' => array(
      'file' => $file,
    ),
  );
}

/**
 * Render API callback: Expands the managed_file element type.
 *
 * Expands the file type to include Upload and Remove buttons, as well as
 * support for a default value.
 *
 * This function is assigned as a #process callback in file_element_info().
 */
function file_managed_file_process($element, &$form_state, $form) {
  // Append the '-upload' to the #id so the field label's 'for' attribute
  // corresponds with the file element.
  $element['#id'] .= '-upload';

  // This is used sometimes so let's implode it just once.
  $parents_prefix = implode('_', $element['#parents']);

  $fids = isset($element['#value']['fids']) ? $element['#value']['fids'] : array();

  // Set some default element properties.
  $element['#progress_indicator'] = empty($element['#progress_indicator']) ? 'none' : $element['#progress_indicator'];
  $element['#files'] = !empty($fids) ? file_load_multiple($fids) : FALSE;
  $element['#tree'] = TRUE;

  $ajax_settings = array(
    'path' => 'file/ajax',
    'options' => array(
      'query' => array(
        'element_parents' => implode('/', $element['#array_parents']),
        'form_build_id' => $form['form_build_id']['#value'],
      ),
    ),
    'wrapper' => $element['#id'] . '-ajax-wrapper',
    'effect' => 'fade',
    'progress' => array(
      'type' => $element['#progress_indicator'],
      'message' => $element['#progress_message'],
    ),
  );

  // Set up the buttons first since we need to check if they were clicked.
  $element['upload_button'] = array(
    '#name' => $parents_prefix . '_upload_button',
    '#type' => 'submit',
    '#value' => t('Upload'),
    '#attributes' => array('class' => array('js-hide')),
    '#validate' => array(),
    '#submit' => array('file_managed_file_submit'),
    '#limit_validation_errors' => array($element['#parents']),
    '#ajax' => $ajax_settings,
    '#weight' => -5,
  );

  // Force the progress indicator for the remove button to be either 'none' or
  // 'throbber', even if the upload button is using something else.
  $ajax_settings['progress']['type'] = ($element['#progress_indicator'] == 'none') ? 'none' : 'throbber';
  $ajax_settings['progress']['message'] = NULL;
  $ajax_settings['effect'] = 'none';
  $element['remove_button'] = array(
    '#name' => $parents_prefix . '_remove_button',
    '#type' => 'submit',
    '#value' => $element['#multiple'] ? t('Remove selected') : t('Remove'),
    '#validate' => array(),
    '#submit' => array('file_managed_file_submit'),
    '#limit_validation_errors' => array($element['#parents']),
    '#ajax' => $ajax_settings,
    '#weight' => 1,
  );

  $element['fids'] = array(
    '#type' => 'hidden',
    '#value' => $fids,
  );

  // Add progress bar support to the upload if possible.
  if ($element['#progress_indicator'] == 'bar' && $implementation = file_progress_implementation()) {
    $upload_progress_key = mt_rand();

    if ($implementation == 'uploadprogress') {
      $element['UPLOAD_IDENTIFIER'] = array(
        '#type' => 'hidden',
        '#value' => $upload_progress_key,
        '#attributes' => array('class' => array('file-progress')),
        // Uploadprogress extension requires this field to be at the top of the
        // form.
        '#weight' => -20,
      );
    }
    elseif ($implementation == 'apc') {
      $element['APC_UPLOAD_PROGRESS'] = array(
        '#type' => 'hidden',
        '#value' => $upload_progress_key,
        '#attributes' => array('class' => array('file-progress')),
        // Uploadprogress extension requires this field to be at the top of the
        // form.
        '#weight' => -20,
      );
    }

    // Add the upload progress callback.
    $element['upload_button']['#ajax']['progress']['path'] = 'file/progress/' . $upload_progress_key;
  }

  // The file upload field itself.
  $element['upload'] = array(
    '#name' => 'files[' . $parents_prefix . ']',
    '#type' => 'file',
    '#title' => t('Choose a file'),
    '#title_display' => 'invisible',
    '#size' => $element['#size'],
    '#multiple' => $element['#multiple'],
    '#theme_wrappers' => array(),
    '#weight' => -10,
  );

  if (!empty($fids) && $element['#files']) {
    foreach ($element['#files'] as $delta => $file) {
      $file_link = array(
        '#theme' => 'file_link',
        '#file' => $file,
      );
      if ($element['#multiple']) {
        $element['file_' . $delta]['selected'] = array(
          '#type' => 'checkbox',
          '#title' => drupal_render($file_link),
        );
      }
      else {
        $element['file_' . $delta]['filename'] = $file_link += array('#weight' => -10);
      }
    }
  }

  // Add the extension list to the page as JavaScript settings.
  if (isset($element['#upload_validators']['file_validate_extensions'][0])) {
    $extension_list = implode(',', array_filter(explode(' ', $element['#upload_validators']['file_validate_extensions'][0])));
    $element['upload']['#attached']['js'] = array(
      array(
        'type' => 'setting',
        'data' => array('file' => array('elements' => array('#' . $element['#id'] => $extension_list)))
      )
    );
  }

  // Prefix and suffix used for Ajax replacement.
  $element['#prefix'] = '<div id="' . $element['#id'] . '-ajax-wrapper">';
  $element['#suffix'] = '</div>';

  return $element;
}

/**
 * Render API callback: Determines the value for a managed_file type element.
 *
 * This function is assigned as a #value_callback in file_element_info().
 */
function file_managed_file_value(&$element, $input, &$form_state) {
  // Find the current value of this field.
  $fids = !empty($input['fids']) ? explode(' ', $input['fids']) : array();
  foreach ($fids as $key => $fid) {
    $fids[$key] = (int) $fid;
  }

  // Process any input and save new uploads.
  if ($input !== FALSE) {
    $input['fids'] = $fids;
    $return = $input;

    // Uploads take priority over all other values.
    if ($files = file_managed_file_save_upload($element, $form_state)) {
      if ($element['#multiple']) {
        $fids = array_merge($fids, array_keys($files));
      }
      else {
        $fids = array_keys($files);
      }
    }
    else {
      // Check for #filefield_value_callback values.
      // Because FAPI does not allow multiple #value_callback values like it
      // does for #element_validate and #process, this fills the missing
      // functionality to allow File fields to be extended through FAPI.
      if (isset($element['#file_value_callbacks'])) {
        foreach ($element['#file_value_callbacks'] as $callback) {
          $callback($element, $input, $form_state);
        }
      }

      // Load files if the FIDs have changed to confirm they exist.
      if (!empty($input['fids'])) {
        $fids = array();
        foreach ($input['fids'] as $fid) {
          if ($file = file_load($fid)) {
            $fids[] = $file->id();
          }
        }
      }
    }
  }

  // If there is no input, set the default value.
  else {
    if ($element['#extended']) {
      $default_fids = isset($element['#default_value']['fids']) ? $element['#default_value']['fids'] : array();
      $return = isset($element['#default_value']) ? $element['#default_value'] : array('fids' => array());
    }
    else {
      $default_fids = isset($element['#default_value']) ? $element['#default_value'] : array();
      $return = array('fids' => array());
    }

    // Confirm that the file exists when used as a default value.
    if (!empty($default_fids)) {
      $fids = array();
      foreach ($default_fids as $fid) {
        if ($file = file_load($fid)) {
          $fids[] = $file->id();
        }
      }
    }
  }

  $return['fids'] = $fids;
  return $return;
}

/**
 * Render API callback: Validates the managed_file element.
 *
 * This function is assigned as a #element_validate callback in
 * file_element_info().
 */
function file_managed_file_validate(&$element, &$form_state) {
  // If referencing an existing file, only allow if there are existing
  // references. This prevents unmanaged files from being deleted if this
  // item were to be deleted.
  $clicked_button = end($form_state['triggering_element']['#parents']);
  if ($clicked_button != 'remove_button' && !empty($element['fids']['#value'])) {
    $fids = $element['fids']['#value'];
    foreach ($fids as $fid) {
      if ($file = file_load($fid)) {
        if ($file->isPermanent()) {
          $references = \Drupal::service('file.usage')->listUsage($file);
          if (empty($references)) {
            form_error($element, $form_state, t('The file used in the !name field may not be referenced.', array('!name' => $element['#title'])));
          }
        }
      }
      else {
        form_error($element, $form_state, t('The file referenced by the !name field does not exist.', array('!name' => $element['#title'])));
      }
    }
  }

  // Check required property based on the FID.
  if ($element['#required'] && empty($element['fids']['#value']) && !in_array($clicked_button, array('upload_button', 'remove_button'))) {
    form_error($element['upload'], $form_state, t('!name field is required.', array('!name' => $element['#title'])));
  }

  // Consolidate the array value of this field to array of FIDs.
  if (!$element['#extended']) {
    form_set_value($element, $element['fids']['#value'], $form_state);
  }
}

/**
 * Form submission handler for upload / remove buttons of managed_file elements.
 *
 * @see file_managed_file_process()
 */
function file_managed_file_submit($form, &$form_state) {
  // Determine whether it was the upload or the remove button that was clicked,
  // and set $element to the managed_file element that contains that button.
  $parents = $form_state['triggering_element']['#array_parents'];
  $button_key = array_pop($parents);
  $element = NestedArray::getValue($form, $parents);

  // No action is needed here for the upload button, because all file uploads on
  // the form are processed by file_managed_file_value() regardless of which
  // button was clicked. Action is needed here for the remove button, because we
  // only remove a file in response to its remove button being clicked.
  if ($button_key == 'remove_button') {
    $fids = array_keys($element['#files']);
    // Get files that will be removed.
    if ($element['#multiple']) {
      $remove_fids = array();
      foreach (Element::children($element) as $name) {
        if (strpos($name, 'file_') === 0 && $element[$name]['selected']['#value']) {
          $remove_fids[] = (int) substr($name, 5);
        }
      }
      $fids = array_diff($fids, $remove_fids);
    }
    else {
      // If we deal with single upload element remove the file and set
      // element's value to empty array (file could not be removed from
      // element if we don't do that).
      $remove_fids = $fids;
      $fids = array();
    }

    foreach ($remove_fids as $fid) {
      // If it's a temporary file we can safely remove it immediately, otherwise
      // it's up to the implementing module to remove usages of files to have them
      // removed.
      if ($element['#files'][$fid] && $element['#files'][$fid]->isTemporary()) {
        $element['#files'][$fid]->delete();
      }
    }
    // Update both $form_state['values'] and $form_state['input'] to reflect
    // that the file has been removed, so that the form is rebuilt correctly.
    // $form_state['values'] must be updated in case additional submit handlers
    // run, and for form building functions that run during the rebuild, such as
    // when the managed_file element is part of a field widget.
    // $form_state['input'] must be updated so that file_managed_file_value()
    // has correct information during the rebuild.
    form_set_value($element['fids'], implode(' ', $fids), $form_state);
    NestedArray::setValue($form_state['input'], $element['fids']['#parents'], implode(' ', $fids));
  }

  // Set the form to rebuild so that $form is correctly updated in response to
  // processing the file removal. Since this function did not change $form_state
  // if the upload button was clicked, a rebuild isn't necessary in that
  // situation and setting $form_state['redirect'] to FALSE would suffice.
  // However, we choose to always rebuild, to keep the form processing workflow
  // consistent between the two buttons.
  $form_state['rebuild'] = TRUE;
}

/**
 * Saves any files that have been uploaded into a managed_file element.
 *
 * @param $element
 *   The FAPI element whose values are being saved.
 * @param array $form_state
 *   An associative array containing the current state of the form.
 *
 * @return
 *   An array of file entities for each file that was saved, keyed by its file
 *   ID, or FALSE if no files were saved.
 */
function file_managed_file_save_upload($element, array &$form_state) {
  $upload_name = implode('_', $element['#parents']);
  $file_upload = \Drupal::request()->files->get("files[$upload_name]", NULL, TRUE);
  if (empty($file_upload)) {
    return FALSE;
  }

  $destination = isset($element['#upload_location']) ? $element['#upload_location'] : NULL;
  if (isset($destination) && !file_prepare_directory($destination, FILE_CREATE_DIRECTORY)) {
    watchdog('file', 'The upload directory %directory for the file field !name could not be created or is not accessible. A newly uploaded file could not be saved in this directory as a consequence, and the upload was canceled.', array('%directory' => $destination, '!name' => $element['#field_name']));
    form_set_error($upload_name, $form_state, t('The file could not be uploaded.'));
    return FALSE;
  }

  // Save attached files to the database.
  $files_uploaded = $element['#multiple'] && count(array_filter($file_upload)) > 0;
  $files_uploaded |= !$element['#multiple'] && !empty($file_upload);
  if ($files_uploaded) {
    if (!$files = file_save_upload($upload_name, $element['#upload_validators'], $destination)) {
      watchdog('file', 'The file upload failed. %upload', array('%upload' => $upload_name));
      form_set_error($upload_name, $form_state, t('Files in the !name field were unable to be uploaded.', array('!name' => $element['#title'])));
      return array();
    }

    // Value callback expects FIDs to be keys.
    $files = array_filter($files);
    $fids = array_map(function($file) { return $file->id(); }, $files);

    return empty($files) ? array() : array_combine($fids, $files);
  }

  return array();
}

/**
 * Returns HTML for a managed file element.
 *
 * @param $variables
 *   An associative array containing:
 *   - element: A render element representing the file.
 *
 * @ingroup themeable
 */
function theme_file_managed_file($variables) {
  $element = $variables['element'];

  $attributes = array();
  if (isset($element['#id'])) {
    $attributes['id'] = $element['#id'];
  }
  if (!empty($element['#attributes']['class'])) {
    $attributes['class'] = (array) $element['#attributes']['class'];
  }
  $attributes['class'][] = 'form-managed-file';

  // This wrapper is required to apply JS behaviors and CSS styling.
  $output = '';
  $output .= '<div' . new Attribute($attributes) . '>';
  $output .= drupal_render_children($element);
  $output .= '</div>';
  return $output;
}

/**
 * Render API callback: Hides display of the upload or remove controls.
 *
 * Upload controls are hidden when a file is already uploaded. Remove controls
 * are hidden when there is no file attached. Controls are hidden here instead
 * of in file_managed_file_process(), because #access for these buttons depends
 * on the managed_file element's #value. See the documentation of form_builder()
 * for more detailed information about the relationship between #process,
 * #value, and #access.
 *
 * Because #access is set here, it affects display only and does not prevent
 * JavaScript or other untrusted code from submitting the form as though access
 * were enabled. The form processing functions for these elements should not
 * assume that the buttons can't be "clicked" just because they are not
 * displayed.
 *
 * This function is assigned as a #pre_render callback in file_element_info().
 *
 * @see file_managed_file_process()
 */
function file_managed_file_pre_render($element) {
  // If we already have a file, we don't want to show the upload controls.
  if (!empty($element['#value']['fids'])) {
    if (!$element['#multiple']) {
      $element['upload']['#access'] = FALSE;
      $element['upload_button']['#access'] = FALSE;
    }
  }
  // If we don't already have a file, there is nothing to remove.
  else {
    $element['remove_button']['#access'] = FALSE;
  }
  return $element;
}

/**
 * Returns HTML for a link to a file.
 *
 * @param $variables
 *   An associative array containing:
 *   - file: A file object to which the link will be created.
 *   - icon_directory: (optional) A path to a directory of icons to be used for
 *     files. Defaults to the value of the "icon.directory"
 *     variable.
 *   - description: A description to be displayed instead of the filename.
 *   - attributes: An associative array of attributes to be placed in the a tag.
 *
 * @ingroup themeable
 */
function theme_file_link($variables) {
  $file = $variables['file'];
  $options = array(
    'attributes' => $variables['attributes'],
  );

  // Set options as per anchor format described at
  // http://microformats.org/wiki/file-format-examples
  $options['attributes']['type'] = $file->getMimeType() . '; length=' . $file->getSize();

  // Use the description as the link text if available.
  if (empty($variables['description'])) {
    $link_text = $file->getFilename();
  }
  else {
    $link_text = $variables['description'];
    $options['attributes']['title'] = check_plain($file->getFilename());
  }

  $file_icon = array(
    '#theme' => 'file_icon',
    '#file' => $file,
    '#icon_directory' => $variables['icon_directory'],
  );

  return '<span class="file">' . drupal_render($file_icon) . ' ' . l($link_text, file_create_url($file->getFileUri()), $options) . '</span>';
}

/**
 * Returns HTML for an image with an appropriate icon for the given file.
 *
 * @param $variables
 *   An associative array containing:
 *   - file: A file entity for which to make an icon.
 *   - icon_directory: (optional) A path to a directory of icons to be used for
 *     files. Defaults to the value of the "icon.directory"
 *     variable.
 *
 * @ingroup themeable
 */
function theme_file_icon($variables) {
  $file = $variables['file'];
  $icon_directory = $variables['icon_directory'];

  $mime = check_plain($file->getMimeType());
  $icon_url = file_icon_url($file, $icon_directory);
  return '<img class="file-icon" alt="" title="' . $mime . '" src="' . $icon_url . '" />';
}

/**
 * Creates a URL to the icon for a file entity.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 * @param $icon_directory
 *   (optional) A path to a directory of icons to be used for files. Defaults to
 *   the value of the "icon.directory" variable.
 *
 * @return
 *   A URL string to the icon, or FALSE if an appropriate icon cannot be found.
 */
function file_icon_url(File $file, $icon_directory = NULL) {
  if ($icon_path = file_icon_path($file, $icon_directory)) {
    return base_path() . $icon_path;
  }
  return FALSE;
}

/**
 * Creates a path to the icon for a file entity.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 * @param $icon_directory
 *   (optional) A path to a directory of icons to be used for files. Defaults to
 *   the value of the "icon.directory" variable.
 *
 * @return
 *   A string to the icon as a local path, or FALSE if an appropriate icon could
 *   not be found.
 */
function file_icon_path(File $file, $icon_directory = NULL) {
  // Use the default set of icons if none specified.
  if (!isset($icon_directory)) {
    $icon_directory = \Drupal::config('file.settings')->get('icon.directory');
  }

  // If there's an icon matching the exact mimetype, go for it.
  $dashed_mime = strtr($file->getMimeType(), array('/' => '-'));
  $icon_path = $icon_directory . '/' . $dashed_mime . '.png';
  if (file_exists($icon_path)) {
    return $icon_path;
  }

  // For a few mimetypes, we can "manually" map to a generic icon.
  $generic_mime = (string) file_icon_map($file);
  $icon_path = $icon_directory . '/' . $generic_mime . '.png';
  if ($generic_mime && file_exists($icon_path)) {
    return $icon_path;
  }

  // Use generic icons for each category that provides such icons.
  foreach (array('audio', 'image', 'text', 'video') as $category) {
    if (strpos($file->getMimeType(), $category . '/') === 0) {
      $icon_path = $icon_directory . '/' . $category . '-x-generic.png';
      if (file_exists($icon_path)) {
        return $icon_path;
      }
    }
  }

  // Try application-octet-stream as last fallback.
  $icon_path = $icon_directory . '/application-octet-stream.png';
  if (file_exists($icon_path)) {
    return $icon_path;
  }

  // No icon can be found.
  return FALSE;
}

/**
 * Determines the generic icon MIME package based on a file's MIME type.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 *
 * @return
 *   The generic icon MIME package expected for this file.
 */
function file_icon_map(File $file) {
  switch ($file->getMimeType()) {
    // Word document types.
    case 'application/msword':
    case 'application/vnd.ms-word.document.macroEnabled.12':
    case 'application/vnd.oasis.opendocument.text':
    case 'application/vnd.oasis.opendocument.text-template':
    case 'application/vnd.oasis.opendocument.text-master':
    case 'application/vnd.oasis.opendocument.text-web':
    case 'application/vnd.openxmlformats-officedocument.wordprocessingml.document':
    case 'application/vnd.stardivision.writer':
    case 'application/vnd.sun.xml.writer':
    case 'application/vnd.sun.xml.writer.template':
    case 'application/vnd.sun.xml.writer.global':
    case 'application/vnd.wordperfect':
    case 'application/x-abiword':
    case 'application/x-applix-word':
    case 'application/x-kword':
    case 'application/x-kword-crypt':
      return 'x-office-document';

    // Spreadsheet document types.
    case 'application/vnd.ms-excel':
    case 'application/vnd.ms-excel.sheet.macroEnabled.12':
    case 'application/vnd.oasis.opendocument.spreadsheet':
    case 'application/vnd.oasis.opendocument.spreadsheet-template':
    case 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet':
    case 'application/vnd.stardivision.calc':
    case 'application/vnd.sun.xml.calc':
    case 'application/vnd.sun.xml.calc.template':
    case 'application/vnd.lotus-1-2-3':
    case 'application/x-applix-spreadsheet':
    case 'application/x-gnumeric':
    case 'application/x-kspread':
    case 'application/x-kspread-crypt':
      return 'x-office-spreadsheet';

    // Presentation document types.
    case 'application/vnd.ms-powerpoint':
    case 'application/vnd.ms-powerpoint.presentation.macroEnabled.12':
    case 'application/vnd.oasis.opendocument.presentation':
    case 'application/vnd.oasis.opendocument.presentation-template':
    case 'application/vnd.openxmlformats-officedocument.presentationml.presentation':
    case 'application/vnd.stardivision.impress':
    case 'application/vnd.sun.xml.impress':
    case 'application/vnd.sun.xml.impress.template':
    case 'application/x-kpresenter':
      return 'x-office-presentation';

    // Compressed archive types.
    case 'application/zip':
    case 'application/x-zip':
    case 'application/stuffit':
    case 'application/x-stuffit':
    case 'application/x-7z-compressed':
    case 'application/x-ace':
    case 'application/x-arj':
    case 'application/x-bzip':
    case 'application/x-bzip-compressed-tar':
    case 'application/x-compress':
    case 'application/x-compressed-tar':
    case 'application/x-cpio-compressed':
    case 'application/x-deb':
    case 'application/x-gzip':
    case 'application/x-java-archive':
    case 'application/x-lha':
    case 'application/x-lhz':
    case 'application/x-lzop':
    case 'application/x-rar':
    case 'application/x-rpm':
    case 'application/x-tzo':
    case 'application/x-tar':
    case 'application/x-tarz':
    case 'application/x-tgz':
      return 'package-x-generic';

    // Script file types.
    case 'application/ecmascript':
    case 'application/javascript':
    case 'application/mathematica':
    case 'application/vnd.mozilla.xul+xml':
    case 'application/x-asp':
    case 'application/x-awk':
    case 'application/x-cgi':
    case 'application/x-csh':
    case 'application/x-m4':
    case 'application/x-perl':
    case 'application/x-php':
    case 'application/x-ruby':
    case 'application/x-shellscript':
    case 'text/vnd.wap.wmlscript':
    case 'text/x-emacs-lisp':
    case 'text/x-haskell':
    case 'text/x-literate-haskell':
    case 'text/x-lua':
    case 'text/x-makefile':
    case 'text/x-matlab':
    case 'text/x-python':
    case 'text/x-sql':
    case 'text/x-tcl':
      return 'text-x-script';

    // HTML aliases.
    case 'application/xhtml+xml':
      return 'text-html';

    // Executable types.
    case 'application/x-macbinary':
    case 'application/x-ms-dos-executable':
    case 'application/x-pef-executable':
      return 'application-x-executable';

    default:
      return FALSE;
  }
}

/**
 * @defgroup file-module-api File module public API functions
 * @{
 * These functions may be used to determine if and where a file is in use.
 */

/**
 * Retrieves a list of references to a file.
 *
 * @param \Drupal\file\File $file
 *   A file entity.
 * @param \Drupal\Core\Field\FieldDefinitionInterface $field
 *   (optional) A field definition to be used for this check. If given, limits the
 *   reference check to the given field.
 * @param $age
 *   (optional) A constant that specifies which references to count. Use
 *   EntityStorageInterface::FIELD_LOAD_REVISION to retrieve all
 *   references within all revisions or
 *   EntityStorageInterface::FIELD_LOAD_CURRENT to retrieve references
 *   only in the current revisions.
 * @param $field_type
 *   (optional) The name of a field type. If given, limits the reference check
 *   to fields of the given type. If both $field and $field_type is given but
 *   $field is not the same type as $field_type, an empty array will be
 *   returned.
 *
 * @return
 *   A multidimensional array. The keys are field_name, entity_type,
 *   entity_id and the value is an entity referencing this file.
 */
function file_get_file_references(File $file, FieldDefinitionInterface $field = NULL, $age = EntityStorageInterface::FIELD_LOAD_REVISION, $field_type = 'file') {
  $references = &drupal_static(__FUNCTION__, array());
  $field_columns = &drupal_static(__FUNCTION__ . ':field_columns', array());

  // Fill the static cache, disregard $field and $field_type for now.
  if (!isset($references[$file->id()][$age])) {
    $references[$file->id()][$age] = array();
    $usage_list = \Drupal::service('file.usage')->listUsage($file);
    $file_usage_list = isset($usage_list['file']) ? $usage_list['file'] : array();
    foreach ($file_usage_list as $entity_type_id => $entity_ids) {
      $entity_type = \Drupal::entityManager()->getDefinition($entity_type_id);
      // The usage table contains usage of every revision. If we are looking
      // for every revision or the entity does not support revisions then
      // every usage is already a match.
      $match_entity_type = $age == EntityStorageInterface::FIELD_LOAD_REVISION || !$entity_type->hasKey('revision');
      $entities = entity_load_multiple($entity_type_id, array_keys($entity_ids));
      foreach ($entities as $entity) {
        $bundle = $entity->bundle();
        // We need to find file fields for this entity type and bundle.
        if (!isset($file_fields[$entity_type_id][$bundle])) {
          $file_fields[$entity_type_id][$bundle] = array();
          // This contains the possible field names.
          foreach ($entity->getFieldDefinitions() as $field_name => $field_definition) {
            $field_type = $field_definition->getType();
            // If this is the first time this field type is seen, check
            // whether it references files.
            if (!isset($field_columns[$field_type])) {
              $field_columns[$field_type] = file_field_find_file_reference_column($field_definition);
            }
            // If the field type does reference files then record it.
            if ($field_columns[$field_type]) {
              $file_fields[$entity_type_id][$bundle][$field_name] = $field_columns[$field_type];
            }
          }
        }
        foreach ($file_fields[$entity_type_id][$bundle] as $field_name => $field_column) {
          $match = $match_entity_type;
          // If we didn't match yet then iterate over the field items to find
          // the referenced file. This will fail if the usage checked is in a
          // non-current revision because field items are from the current
          // revision.
          if (!$match && ($items = $entity->get($field_name))) {
            foreach ($items as $item) {
              if ($file->id() == $item->{$field_column}) {
                $match = TRUE;
                break;
              }
            }
          }
          if ($match) {
            $references[$file->id()][$age][$field_name][$entity_type_id][$entity->id()] = $entity;
          }
        }
      }
    }
  }
  $return = $references[$file->id()][$age];
  // Filter the static cache down to the requested entries. The usual static
  // cache is very small so this will be very fast.
  if ($field || $field_type) {
    foreach ($return as $field_name => $data) {
      foreach (array_keys($data) as $entity_type_id) {
        $field_storage_definitions = \Drupal::entityManager()->getFieldStorageDefinitions($entity_type_id);
        $current_field = $field_storage_definitions[$field_name];
        if (($field_type && $current_field->getType() != $field_type) || ($field && $field->uuid() != $current_field->uuid())) {
          unset($return[$field_name][$entity_type_id]);
        }
      }
    }
  }
  return $return;
}

/**
 * @} End of "defgroup file-module-api".
 */

/**
 * Implements hook_permission().
 */
function file_permission() {
  $perms = array(
    'access files overview' => array(
      'title' => t('Access the Files overview page'),
      'description' => user_access('access files overview')
        ? t('Get an overview of <a href="@url">all files</a>.', array('@url' => url('admin/content/files')))
        : t('Get an overview of all files.'),
    ),
  );

  return $perms;
}

/**
 * Formats human-readable version of file status.
 *
 * @param int $choice
 *   integer Status code.
 * @return string
 *   string Text-represented file status.
 */
function _views_file_status($choice = NULL) {
  $status = array(
    0 => t('Temporary'),
    FILE_STATUS_PERMANENT => t('Permanent'),
  );

  if (isset($choice)) {
    return isset($status[$choice]) ? $status[$choice] : t('Unknown');
  }

  return $status;
}