Calling the extension

When a user opens the web page containing our blog in their browser, this request (Request) will be forwarded to the remote TYPO3 server. Then TYPO3 starts the processing of this request straight away.

A request generally contains the page’s identifier (the so-called page slug) that should be generated (e. g. /blog). Using this page identifier, TYPO3 searches all relevant content elements on the specific page and collects their generated HTML code one after another. While processing this page request, TYPO3 discovers the content element for this example extension, the so-called plugin. This plugin should display a list of all blogs. Each with an individual title, a short description, and the amount of all enclosed posts. In figure 3-4, you can see the output of the plugin in the frontend. This output is embedded within the greater overview of the page.

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Figure 3-4: Output of the plugin of the example extension

The process of eradication is first forwarded to the dispatcher of Extbase by TYPO3. The dispatcher and the parent Boostrap complete several preliminary tasks before they hand the further processing on to the according position within the code of the blog example, which is part of the ActionController:

  • The RequestBuilder interprets the incoming request and bundles all relevant information into a Request object.
  • The Extbase Bootstrap loads the configuration of the extension from the different sources and makes it available.
  • The ActionController determines whether or not the request was manipulated in an illegal manner and when this is the case, it deflects it (e.g. in case of a maliciously added form input field).
  • The extension contains a set up of the persistence layer, which performs the persisting of new or changed objects. This is done in a mechanism of the Bootstrap, that automatically saves pending domain objects.
  • The extension contains definitions for the TYPO3 cache, by which the content is stored for faster reuse. TYPO3 will take care of this.
  • The dispatcher instantiates the controller of the extension depending on its configuration. The ActionController controls the further processing within the extension.

When these preparations are fulfilled, you can travel to the destination’s first stop: the ActionController which will be present under different names. In this example, all further processing is assigned to the BlogController. A reference to the request is handed over.

The class BlogController can be found in the file EXT:blog_example/Classes/Controller/BlogController.php. The complete name of the controller namespace class is \MyVendor\BlogExample\Controller\BlogController. At first this might seem long-winded, but the syntax follows a very strict convention.