The API for expanding the panels module comes in two pieces. First there is the layout API, which adds to the list of layouts you need. Second is the content types API, which lets modules supply content to the panels. Natively, panels module supports the content types of 'block', which just renders the output of a block, 'node' which simply renders a node_view, 'custom' which allows the user to enter custom content with filtering, and finally 'views' because I wrote them both. Where to put your code: ======================= With both types, there are two ways to implement a new type. First, you can implement the hook in your module and provide the necessary data. Or you can create a .inc file in the right format, and drop it into the proper directory in the panels module. Both are very similar, and only requires a minor naming adjustment. When using the .inc file, in place of 'hook' in the various hooks, use panels_FILENAME. Creating a new Layout Type: =========================== A layout consists of 4 things: 1) A bit of HTML in a theme function. I use heredoc notation to make it extra easy to convert these to .tpl.inc files in case they are to be overridden in php template. 2) A bit of CSS to describe how the layout should be, well, laid out. 3) An icon that is 50x75 which gives the user a visual indication of what the layout looks like. 4) An implementation of hook_panels_layouts() to tell panels the necessary information. hook_panels_layouts returns an array with the following information: 'module' => The module name providing this. This is necessary because it uses drupal_get_path('module', $module) to get the proper path for included CSS. 'title' => The title of the layout presented to the user. Use t(). 'icon' => The filename of the icon to use when listing avialable layouts. 'theme' => The theme function that contains the HTML, without the theme_ part. 'css' => The CSS file. 'content areas' => an array in the form of 'name' => t('Title') of content areas supported by the layout. For example, the simple 2 column layout uses array('left' => t('Left side'), 'right' => t('Right side')); -- the name is the internal identifier. Your theme function will see it as $content['name'] (so twocol gets $content['left'] and $content['right']). Creating a new Content Type: ============================ Content types require 1 hook and two callbacks. The hook defines what content types are available, the first callback displays the content in a dashboard, and the other callback does all of the administrative functions. hook_panels_content_types returns an array with the following information: 'callback' => The function to display the content. 'admin' => The function to administer the content. The callback function receives one argument: The $configuration array, as defined by the administrative callback. The administrative callback recieves 3 arguments: $op -- the operation to perform. See below. &$arg1 -- The first argument should be a reference and its meaning varies based on the op. $arg2 -- The second argument is optional, not a reference, and should default to NULL. Administrative operations: 'list': $arg1 is the configuration array. This op is called when panels lists what content is in a content area. It generally returns something similar to this: return 'Views: ' . $view->name . ' (' . $view->description . ')'; 'add button': arguments not used here. This op is called to display the 'add content type' button; it can also display additional information (such as the list of blocks or the autocomplete to select a node). The actual button should look something like this: $form['submit'] = array( '#type' => 'button', '#value' => t('Add view'), ); And it's a good idea to do this, but it's not required: $form['#prefix'] = '
'; $form['#suffix'] = '
'; 'add': $arg1 == the $configuration array This op is called to see if your add button has been clicked. It *must* start off by checking to see if this is true: if ($_POST['op'] != t('Add view')) { return; } If it is true, it should process that information and return a $configuration array populated from whatever other form items were presented in 'add button' and whatever defaults make sense. 'edit': $arg1 == the $configuration array This op is called to provide an edit form for a content type. It *must* ensure *all* information from the conf array is available, even if it is just hidden; panels has no way to remember this data between form clicks, so any data not put here will be lost. No buttons need to be added to the form. 'validate': $arg1 == $form_values, $arg2 == $form Called to validate the 'edit' form above. 'save': $arg1 == $form_values Called to convert a $form_values back into a $configuration array. All of the default types just send $form_values back as $configuration, but if you need to do some kind of transformation, this is where it happens.