View source for Cchost/developer/Hooking Page Render

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Page rendering happens in 2 main phases in the CCPage class. In Phase 1 all the variables are gathered into a huge variable array. In Phase 2 CCPage calls down to it's base class, CCSkin, to merge the variables with the config-selected page template.

Right before Phase 2 happens, CCPage triggers an event to let any custom code prepare any last minute hacks before handing off to the template engine (CCSkin).

If you create a module that hooks that event you can manipulate the variables (er, hack at the array) to change the appearance of any/all pages.

An example: (put the following code with a PHP extension into your '''<local_files>/lib''' directory):


  CCEvents::AddHandler(CC_EVENT_RENDER_PAGE,  'page_trapper' );
 
  function page_trapper( &$page )
  {
     // This might be an array (I think)
     $caption =& $page->vars['page-caption'];
 
     // same with this
     $title =& $page->vars['page-title'];
 
     $caption = 'CAP: ' . $caption;
     $title = 'TITLE: ' . $title;
  }

The code above will simply append strings to the caption and title to every page in the system. If you are looking for a specific page you can for that page's title (e.g. 'str_file_deleting').

Of course your hacks are not limited to these variables. You can also, say, remove the bread crumbs from specific page by simply null-ing out the 'bread_crumbs' var:

  CCEvents::AddHandler(CC_EVENT_RENDER_PAGE,  'page_trapper' );
 
  function page_trapper( &$page )
  {
     $title =& $page->vars['page-title'];
 
     if( $title == 'str_file_deleting' )
     {
        unset( $page->vars['bread_crumbs'] );
     }
  }

In order to get a full idea of what variables are available you can inspect the page object:

   CCDebug::Enable(true);
   CCDebug::PrintVar($page);

And don't forget about [[Cchost/guide/Troubleshooting#Variable_Dumps|variable dumps]].