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How to do it...

How it works...

Let's review the ModuleUrlManager::collectRules method.

If there are modules defined in our application, then we are checking if urlRules public property exists. If it does, then there are some rules defined in the module and they are added using CUrlManager::addRules.

CUrlManager::addRules description says "In order to make the new rules effective, this method must be called before CWebApplication::processRequest".

Now, let's check how our application works. In our index.php, we have the following line:

Yii::createWebApplication($config)->run();

After being initialized with configuration, we are calling CWebApplication::run():

public function run()
{
   if($this->hasEventHandler('onBeginRequest'))
      $this->onBeginRequest(new CEvent($this));
   $this->processRequest();
   if($this->hasEventHandler('onEndRequest'))
      $this->onEndRequest(new CEvent($this));
}

As we can see, there is an onBeginRequest event raised just before calling processRequest. That is why we are attaching our class method to it.

There's more...

As instantiating all application modules on every request is not good for performance, it is good to cache module rules. Caching strategy can vary depending on your application. Let's implement a simple one:

<?php
class ModuleUrlManager
{
  static function collectRules(){
    if(!empty(Yii::app()->modules))
    {
      $cache = Yii::app()->getCache();

      foreach(Yii::app()->modules as $moduleName => $config)
      {
         $urlRules = false;

         if($cache)
           $urlRules = $cache->get('module.urls.'.$moduleName);            

         if($urlRules===false){
           $urlRules = array();
           $module = Yii::app()->getModule($moduleName);
           if(isset($module->urlRules))
              $urlRules = $module->urlRules;

           if($cache)
              $cache->set('module.urls.'.$moduleName, $urlRules);
         }
         if(!empty($urlRules))
           Yii::app()->getUrlManager()->addRules($urlRules);
      }
   }

   return true;
  }
}

This implementation caches URL rules per module. So, adding new modules is not a problem but changing existing ones requires you to flush cache manually using Yii::app()->cache->flush().

See also