The filters.yml Configuration File

The ~filters.yml~ configuration file describes the filter chain to be executed for every request.

The main filters.yml configuration file for an application can be found in the apps/APP_NAME/config/ directory.

As discussed in the introduction, the filters.yml file benefits from the configuration cascade mechanism, and can include constants.

The filters.yml configuration file contains a list of named filter definitions:

---
FILTER_1:
  # definition of filter 1

FILTER_2:
  # definition of filter 2

# ...

When the controller initializes the filter chain for a request, it reads the filters.yml file and registers the filters by looking for the class name of the filter (class) and the parameters (param) used to configure the filter object:

---
FILTER_NAME:
  class: CLASS_NAME
  param: { ARRAY OF PARAMETERS }

The filters are executed in the same order as they appear in the configuration file. As symfony executes the filters as a chain, the first registered filter is executed first and last.

The class name should extend the sfFilter base class.

If the filter class cannot be autoloaded, a file path can be defined and will be automatically included before the filter object is created:

---
FACTORY_NAME:
  class: CLASS_NAME
  file:  ABSOLUTE_PATH_TO_FILE

When you override the filters.yml file, you must keep all filters from the inherited configuration file:

---
rendering:
security:
cache:
execution:

To remove a filter, you need to disable it by setting the enabled key to false:

---
FACTORY_NAME:
  enabled: false

There are two special name filters: rendering and execution. They are both mandatory and are identified with the type parameter. The rendering filter should always be the first registered filter and the execution filter should be the last one:

---
rendering:
  class: sfRenderingFilter
  param:
    type: rendering

# ...

execution:
  class:  sfExecutionFilter
  param:
    type: execution

The filters.yml configuration file is cached as a PHP file; the process is automatically managed by the ~sfFilterConfigHandler~ class.

Filters

• rendering
• security
• cache
• execution

rendering

Default configuration:

---
rendering:
  class: sfRenderingFilter
  param:
    type: rendering

The rendering filter is responsible for the output of the response to the browser. As it should be the first filter registered, it is also the last one to have a chance to manage the request.

security

Default configuration:

---
security:
   class: sfBasicSecurityFilter
   param:
     type: security

The security filter checks the security by calling the getCredential() method of the action. Once the credential has been acquired, it verifies that the user has the same credential by calling the hasCredential() method of the user object.

The security filter must have a type of security.

The fine-grained configuration of the security filter is done via the security.yml configuration file.

If the requested action is not configured as secure in security.yml, the security filter will not be executed.

cache

Default configuration:

---
cache:
  class: sfCacheFilter
  param:
    condition: %SF_CACHE%

The cache filter manages the caching of actions and pages. It is also responsible for adding the needed HTTP cache headers to the response (Last-Modified, ETag, Cache-Control, Expires, ...).

execution

Default configuration:

---
execution:
  class:  sfExecutionFilter
  param:
    type: execution

The execution filter is at the center of the filter chain and does all action and view execution.

The execution filter should be the last registered filter.