Context 3.x API --------------- The following is an overview of using the Context API. The context static cache ------------------------ Context provides a centralized set of API functions for setting and retrieving a static cache: // Set a static cache value at [my_namspace][mykey] context_set('my_namespace', 'mykey', $value); // Retrieve a static cache value at [my_namespace][mykey] context_get('my_namespace', 'mykey'); // $value // Boolean for whether there is a value at [my_namespace][mykey] context_isset('my_namespace', 'mykey'); // TRUE These are used internally by context but may also be used by other modules. Just do not use the namespace `context` unless you want to affect things that context is up to. Adding a condition or reaction plugin ------------------------------------- Both context conditions and reactions utilize the CTools plugins API. In order to add a new condition or reaction for your module, follow these steps: 1. Implement `hook_context_plugins()` to define your plugins, classes, and class hierarchy. function mymodule_context_plugins() { $plugins = array(); $plugins['mymodule_context_condition_bar'] = array( 'handler' => array( 'path' => drupal_get_path('module', 'mymodule') .'/plugins', 'file' => 'mymodule_context_condition_bar.inc', 'class' => 'mymodule_context_condition_bar', 'parent' => 'context_condition', ), ); return $plugins; } 2. Implement `hook_context_registry()` to define your conditions and/or reactions and map them to plugins. function mymodule_context_registry() { return array( 'conditions' => array( 'bar' => array( 'title' => t('Name of condition "bar"'), 'plugin' => 'mymodule_context_condition_bar', ), ), ); } 3. Write your condition or reaction plugin class. It's best to look at one of the included plugins as a starting point. 4. Add in a Drupal integration point for your plugin. A node page condition plugin, for example, may be invoked from `hook_nodeapi()`. Replacing or extending existing plugins --------------------------------------- You can replace a condition or reaction plugin with your own plugin class using `hook_context_registry_alter()`: function mymodule_context_registry_alter(&$registry) { if (!empty($registry['conditions']['node'])) { $registry['conditions']['node']['plugin'] = 'mymodule_context_condition_customnode'; } } This entry would swap out the default node condition plugin for a custom one provided by `mymodule`. Note that any replacement plugins must have an entry in `hook_context_plugins()`.