Development

Documentation/ja_JP/book/1.0/06-Inside-the-Controller-Layer (diff)

You must first sign up to be able to contribute.

Changes from Version 1 of Documentation/ja_JP/book/1.0/06-Inside-the-Controller-Layer

Show
Ignore:
Author:
heihachiro (IP: 125.100.73.82)
Timestamp:
02/08/07 12:31:57 (11 years ago)
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • Documentation/ja_JP/book/1.0/06-Inside-the-Controller-Layer

    v0 v1  
     1 
     2{{{ 
     3#!WikiMarkdown 
     4Chapter 6 - Inside The Controller Layer 
     5======================================= 
     6 
     7In symfony, the controller layer, which contains the code linking the business logic and the presentation, is split into several components that you use for different purposes: 
     8 
     9  * The front controller is the unique entry point to the application. It loads the configuration and determines the action to execute. 
     10  * Actions contain the applicative logic. They check the integrity of the request and prepare the data needed by the presentation layer. 
     11  * The request, response, and session objects give access to the request parameters, the response headers, and the persistent user data. They are used very often in the controller layer. 
     12  * Filters are portions of code executed for every request, before or after the action. For example, the security and validation filters are commonly used in web applications. You can extend the framework by creating your own filters. 
     13 
     14This chapter describes all these components, but don't be intimidated by their number. For a basic page, you will probably need to write only a few lines in the action class, and that's all. The other controller components will be of use only in specific situations. 
     15 
     16The Front Controller 
     17-------------------- 
     18 
     19All web requests are handled by a single front controller, which is the unique entry point to the whole application in a given environment. 
     20 
     21When the front controller receives a request, it uses the routing system to match an action name and a module name with the URL typed (or clicked) by the user. For instance, the following request URL calls the `index.php` script (that's the front controller) and will be understood as a call to the action `myAction` of the module `mymodule`: 
     22 
     23    http://localhost/index.php/mymodule/myAction 
     24 
     25If you are not interested in symfony's internals, that's all that you need to know about the front controller. It is an indispensable component of the symfony MVC architecture, but you will seldom need to change it. So you can jump to the next section unless you really want to know about the guts of the front controller. 
     26 
     27### The Front Controller's Job in Detail 
     28 
     29The front controller does the dispatching of the request, but that means a little more than just determining the action to execute. In fact, it executes the code that is common to all actions, including the following: 
     30 
     31  1. Define the core constants. 
     32  2. Locate the symfony libraries. 
     33  3. Load and initiate the core framework classes. 
     34  4. Load the configuration. 
     35  5. Decode the request URL to determine the action to execute and the request parameters. 
     36  6. If the action does not exist, redirect to the 404 error action. 
     37  7. Activate filters (for instance, if the request needs authentication). 
     38  8. Execute the filters, first pass. 
     39  9. Execute the action and render the view. 
     40  10. Execute the filters, second pass. 
     41  11. Output the response. 
     42 
     43### The Default Front Controller 
     44 
     45The default front controller, called `index.php` and located in the `web/` directory of the project, is a simple PHP file, as shown in Listing 6-1. 
     46 
     47Listing 6-1 - The Default Production Front Controller 
     48 
     49    [php] 
     50    <?php 
     51 
     52    define('SF_ROOT_DIR',    realpath(dirname(__FILE__).'/..')); 
     53    define('SF_APP',         'myapp'); 
     54    define('SF_ENVIRONMENT', 'prod'); 
     55    define('SF_DEBUG',       false); 
     56 
     57    require_once(SF_ROOT_DIR.DIRECTORY_SEPARATOR.'apps'.DIRECTORY_SEPARATOR.SF_APP.DIRECTORY_SEPARATOR.'config'.DIRECTORY_SEPARATOR.'config.php'); 
     58 
     59    sfContext::getInstance()->getController()->dispatch(); 
     60 
     61The constants definition corresponds to the first step described in the previous section. Then the front controller includes the application config.php, which takes care of steps 2 through 4. The call to the dispatch() method of the `sfController` object (which is the core controller object of the symfony MVC architecture) dispatches the request, taking care of steps 5 through 7. The last steps are handled by the filter chain, as explained later in this chapter. 
     62 
     63### Calling Another Front Controller to Switch the Environment 
     64 
     65One front controller exists per environment. As a matter of fact, it is the very existence of a front controller that defines an environment. The environment is defined in the `SF_ENVIRONMENT` constant. 
     66 
     67To change the environment in which you're browsing your application, just choose another front controller. The default front controllers available when you create a new application with the `symfony init-app` task are `index.php` for the production environment and `myapp_dev.php` for the development environment (provided that your application is called `myapp`). The default `mod_rewrite` configuration will use `index.php` when the URL doesn't contain a front controller script name. So both of these URLs display the same page (`mymodule/index`) in the production environment: 
     68 
     69    http://localhost/index.php/mymodule/index 
     70    http://localhost/mymodule/index 
     71 
     72and this URL displays that same page in the development environment: 
     73 
     74    http://localhost/myapp_dev.php/mymodule/index 
     75 
     76Creating a new environment is as easy as creating a new front controller. For instance, you may need a staging environment to allow your customers to test the application before going to production. To create this staging environment, just copy `web/myapp_dev.php` into `web/myapp_staging.php`, and change the value of the `SF_ENVIRONMENT` constant to `staging`. Now, in all the configuration files, you can add a new `staging:` section to set specific values for this environment, as shown in Listing 6-2. 
     77 
     78Listing 6-2 - Sample `app.yml` with Specific Settings for the Staging Environment 
     79 
     80    staging: 
     81      mail: 
     82        webmaster:    dummy@mysite.com 
     83        contact:      dummy@mysite.com 
     84    all: 
     85      mail: 
     86        webmaster:    webmaster@mysite.com 
     87        contact:      contact@mysite.com 
     88 
     89If you want to see how the application reacts in this new environment, call the related front controller: 
     90 
     91    http://localhost/myapp_staging.php/mymodule/index 
     92 
     93### Batch Files 
     94 
     95You may want to execute a script from the command line (or via a cron table) with access to all the symfony classes and features, for instance to launch batch e-mail jobs or to periodically update your model through a process-intensive calculation. For such a script, you need to include the same lines as in a front controller at the beginning. Listing 6-3 shows an example of the beginning of a batch script. 
     96 
     97Listing 6-3 - Sample Batch Script 
     98 
     99    [php] 
     100    <?php 
     101 
     102    define('SF_ROOT_DIR',    realpath(dirname(__FILE__).'/..')); 
     103    define('SF_APP',         'myapp'); 
     104    define('SF_ENVIRONMENT', 'prod'); 
     105    define('SF_DEBUG',       false); 
     106 
     107    require_once(SF_ROOT_DIR.DIRECTORY_SEPARATOR.'apps'.DIRECTORY_SEPARATOR.SF_APP.DIRECTORY_SEPARATOR.'config'.DIRECTORY_SEPARATOR.'config.php'); 
     108 
     109    // add code here 
     110 
     111You can see that the only missing line is the call to the dispatch() method of the sfController object, which can be used only with a web server, not in a batch process. Defining an application and an environment gives you access to a specific configuration. Including the application `config.php` initiates the context and the autoloading. 
     112 
     113>**TIP** 
     114>The symfony CLI offers an `init-batch` task, which automatically creates a skeleton similar to the one in Listing 6-3 in the `batch/` directory. Just pass it an application name, an environment name, and a batch name as arguments. 
     115 
     116Actions 
     117------- 
     118 
     119The actions are the heart of an application, because they contain all the application's logic. They use the model and define variables for the view. When you make a web request in a symfony application, the URL defines an action and the request parameters. 
     120 
     121### The Action Class 
     122 
     123Actions are methods named `executeActionName` of a class named `moduleNameActions` inheriting from the `sfActions` class, and grouped by modules. The action class of a module is stored in an `actions.class.php` file, in the module's `actions/` directory. 
     124 
     125Listing 6-4 shows an example of an `actions.class.php` file with only an `index` action for the whole `mymodule` module. 
     126 
     127Listing 6-4 - Sample Action Class, in `apps/myapp/modules/mymodule/actions/actions.class.php` 
     128 
     129    [php] 
     130    class mymoduleActions extends sfActions 
     131    { 
     132      public function executeIndex() 
     133      { 
     134 
     135      } 
     136    } 
     137 
     138>**CAUTION** 
     139>Even if method names are not case-sensitive in PHP, they are in symfony. So don't forget that the action methods must start with a lowercase `execute`, followed by the exact action name with the first letter capitalized. 
     140 
     141In order to request an action, you need to call the front controller script with the module name and action name as parameters. By default, this is done by appending the couple `module_name`/`acti`on_name to the script. This means that the action defined in Listing 6-4 can be called by this URL: 
     142 
     143    http://localhost/index.php/mymodule/index 
     144 
     145Adding more actions just means adding more `execute` methods to the `sfActions` object, as shown in Listing 6-5. 
     146 
     147Listing 6-5 - Action Class with Two Actions, in myapp/modules/mymodule/actions/actions.cla`ss.php` 
     148 
     149    [php] 
     150    class mymoduleActions extends sfActions 
     151    { 
     152      public function executeIndex() 
     153      { 
     154        ... 
     155      } 
     156 
     157      public function executeList() 
     158      { 
     159        ... 
     160      } 
     161    } 
     162 
     163If the size of an action class grows too much, you probably need to do some refactoring and move some code to the model layer. Actions should often be kept short (not more than a few lines), and all the business logic should usually be in the model. 
     164 
     165Still, the number of actions in a module can be important enough to lead you to split it in two modules. 
     166 
     167>**SIDEBAR** 
     168>Symfony coding standards 
     169> 
     170>In the code examples given in this book, you probably noticed that the opening and closing curly braces (`{` and `}`) occupy one line each. This standard makes the code easier to read. 
     171> 
     172>Among the other coding standards of the framework, indentation is always done by two blank spaces; tabs are not used. This is because tabs have a different space value according to the text editor you use, and because code with mixed tab and blank indentation is impossible to read. 
     173> 
     174>Core and generated symfony PHP files do not end with the usual `?>` closing tag. This is because it is not really needed, and because it can create problems in the output if you ever have blanks after this tag. 
     175> 
     176>And if you really pay attention, you will see that a line never ends with a blank space in symfony. The reason, this time, is more prosaic: lines ending with blanks look ugly in Fabien's text editor. 
     177 
     178### Alternative Action Class Syntax 
     179 
     180An alternative action syntax is available to dispatch the actions in separate files, one file per action. In this case, each action class extends `sfAction` (instead of `sfActions`) and is named `actionNameAction`. The actual action method is simply named `execute`. The file name is the same as the class name. This means that the equivalent of Listing 6-5 can be written with the two files shown in Listings 6-6 and 6-7. 
     181 
     182Listing 6-6 - Single Action File, in `myapp/modules/mymodule/actions/indexAction.class.php` 
     183 
     184    [php] 
     185    class indexAction extends sfAction 
     186    { 
     187      public function execute() 
     188      { 
     189        ... 
     190      } 
     191    } 
     192 
     193Listing 6-7 - Single Action File, in `myapp/modules/mymodule/actions/listAction.class.php` 
     194 
     195    [php] 
     196    class listAction extends sfAction 
     197    { 
     198      public function execute() 
     199      { 
     200        ... 
     201      } 
     202    } 
     203 
     204### Retrieving Information in the Action 
     205 
     206The action class offers a way to access controller-related information and the core symfony objects. Listing 6-8 demonstrates how to use them. 
     207 
     208Listing 6-8 - `sfActions` Common Methods 
     209 
     210    [php] 
     211    class mymoduleActions extends sfActions 
     212    { 
     213      public function executeIndex() 
     214      { 
     215        // Retrieving request parameters 
     216        $password    = $this->getRequestParameter('password'); 
     217 
     218        // Retrieving controller information 
     219        $moduleName  = $this->getModuleName(); 
     220        $actionName  = $this->getActionName(); 
     221 
     222        // Retrieving framework core objects 
     223        $request     = $this->getRequest(); 
     224        $userSession = $this->getUser(); 
     225        $response    = $this->getResponse(); 
     226        $controller  = $this->getController(); 
     227        $context     = $this->getContext(); 
     228 
     229        // Setting action variables to pass information to the template 
     230        $this->setVar('foo', 'bar'); 
     231        $this->foo = 'bar';            // Shorter version 
     232 
     233      } 
     234    } 
     235 
     236>**SIDEBAR** 
     237>The context singleton 
     238> 
     239>You already saw, in the front controller, a call to sfContext::getInstance(). In an action, the getContext() method returns the same singleton. It is a very useful object that stores a reference to all the symfony core objects related to a given request, and offers an accessor for each of them: 
     240> 
     241>`sfController`: The controller object (`->getController()`) `sfRequest`: The request object (`->getRequest()`) `sfResponse`: The response object (`->getResponse()`) `sfUser`: The user session object (`->getUser()`) `sfDatabaseConnection`: The database connection (`->getDatabaseConnection()`) `sfLogger`: The logger object (`->getLogger()`) `sfI18N`: The internationalization object (`->getI18N()`) 
     242> 
     243>You can call the `sfContext::getInstance()` singleton from any part of the code. 
     244 
     245### Action Termination 
     246 
     247Various behaviors are possible at the conclusion of an action's execution. The value returned by the action method determines how the view will be rendered. Constants of the `sfView` class are used to specify which template is to be used to display the result of the action. 
     248 
     249If there is a default view to call (this is the most common case), the action should end as follows: 
     250 
     251    [php] 
     252    return sfView::SUCCESS; 
     253 
     254Symfony will then look for a template called `actionNameSuccess.php`. This is defined as the default action behavior, so if you omit the `return` statement in an action method, symfony will also look for an `actionNameSuccess.php` template. Empty actions will also trigger that behavior. See Listing 6-9 for examples of successful action termination. 
     255 
     256Listing 6-9 - Actions That Will Call the `indexSuccess.php` and `listSuccess.php` Templates 
     257 
     258    [php] 
     259    public function executeIndex() 
     260    { 
     261      return sfView::SUCCESS; 
     262    } 
     263 
     264    public function executeList() 
     265    { 
     266    } 
     267 
     268If there is an error view to call, the action should end like this: 
     269 
     270    [php] 
     271    return sfView::ERROR; 
     272 
     273Symfony will then look for a template called `actionNameError.php`. 
     274 
     275To call a custom view, use this ending: 
     276 
     277    [php] 
     278    return 'MyResult'; 
     279 
     280Symfony will then look for a template called `actionNameMyResult.php`. 
     281 
     282If there is no view to call--for instance, in the case of an action executed in a batch process--the action should end as follows: 
     283 
     284    [php] 
     285    return sfView::NONE; 
     286 
     287No template will be executed in that case. It means that you can bypass completely the view layer and output HTML code directly from an action. As shown in Listing 6-10, symfony provides a specific renderText() method for this case. This can be useful when you need extreme responsiveness of the action, such as for Ajax interactions, which will be discussed in Chapter 11. 
     288 
     289Listing 6-10 - Bypassing the View by Echoing the Response and Returning `sfView::NONE` 
     290 
     291    [php] 
     292    public function executeIndex() 
     293    { 
     294      echo "<html><body>Hello, World!</body></html>"; 
     295 
     296      return sfView::NONE; 
     297    } 
     298 
     299    // Is equivalent to 
     300    public function executeIndex() 
     301    { 
     302      return $this->renderText("<html><body>Hello, World!</body></html>"); 
     303    } 
     304 
     305In some cases, you need to send an empty response but with some headers defined in it (especially the `X-JSON` header). Define the headers via the `sfResponse` object, discussed in the next chapter, and return the `sfView::HEADER_ONLY` constant, as shown in Listing 6-11. 
     306 
     307Listing 6-11 - Escaping View Rendering and Sending Only Headers 
     308 
     309    [php] 
     310    public function executeRefresh() 
     311    { 
     312      $output = '<"title","My basic letter"],["name","Mr Brown">'; 
     313      $this->getResponse()->setHttpHeader("X-JSON", '('.$output.')'); 
     314 
     315      return sfView::HEADER_ONLY; 
     316    } 
     317 
     318If the action must be rendered by a specific template, ignore the `return` statement and use the `setTemplate()` method instead. 
     319 
     320    [php] 
     321    $this->setTemplate('myCustomTemplate'); 
     322 
     323### Skipping to Another Action 
     324 
     325In some cases, the action execution ends by requesting a new action execution. For instance, an action handling a form submission in a POST request usually redirects to another action after updating the database. Another example is an action alias: the `index` action is often a way to display a list, and actually forwards to a `list` action. 
     326 
     327The action class provides two methods to execute another action: 
     328 
     329  * If the action forwards the call to another action: 
     330 
     331    [php] 
     332    $this->forward('otherModule', 'index'); 
     333 
     334  * If the action results in a web redirection: 
     335 
     336    [php] 
     337    $this->redirect('otherModule/index'); 
     338    $this->redirect('http://www.google.com/'); 
     339 
     340>**NOTE** 
     341>The code located after a forward or a redirect in an action is never executed. You can consider that these calls are equivalent to a `return` statement. They throw an `sfStopException` to stop the execution of the action; this exception is later caught by symfony and simply ignored. 
     342 
     343The choice between a redirect or a forward is sometimes tricky. To choose the best solution, keep in mind that a forward is internal to the application and transparent to the user. As far as the user is concerned, the displayed URL is the same as the one requested. In contrast, a redirect is a message to the user's browser, involving a new request from it and a change in the final resulting URL. 
     344 
     345If the action is called from a submitted form with `method="post"`, you should always do a redirect. The main advantage is that if the user refreshes the resulting page, the form will not be submitted again; in addition, the back button works as expected by displaying the form and not an alert asking the user if he wants to resubmit a POST request. 
     346 
     347There is a special kind of forward that is used very commonly. The `forward404()` method forwards to a "page not found" action. This method is often called when a parameter necessary to the action execution is not present in the request (thus detecting a wrongly typed URL). Listing 6-12 shows an example of a `show` action expecting an `id` parameter. 
     348 
     349Listing 6-12 - Use of the `forward404()` Method 
     350 
     351    [php] 
     352    public function executeShow() 
     353    { 
     354      $article = ArticlePeer::retrieveByPK($this->getRequestParameter('id')); 
     355      if (!$article) 
     356      { 
     357        $this->forward404(); 
     358      } 
     359    } 
     360 
     361>**TIP** 
     362>If you are looking for the error 404 action and template, you will find them in the `$sf_symfony_ data_dir/modules/default/` directory. You can customize this page by adding a new `default` module to your application, overriding the one located in the framework, and by defining an `error404` action and an error404Success template inside. Alternatively, you can set the error_404_module and error_404_ action constants in the `settings.yml` file to use an existing action. 
     363 
     364Experience shows that, most of the time, an action makes a redirect or a forward after testing something, such as in Listing 6-12. That's why the sfActions class has a few more methods, named forwardIf(), forwardUnless(), forward404If(), forward404Unless(), redirectI`f()`, and `r`edirectUnless(). These methods simply take an additional parameter representing a condition that triggers the execution if tested true (for the xxxIf() methods) or false (for the xxxUnless() methods), as illustrated in Listing 6-13. 
     365 
     366Listing 6-13 - Use of the `forward404If()` Method 
     367 
     368    [php] 
     369    // This action is equivalent to the one shown in Listing 6-12 
     370    public function executeShow() 
     371    { 
     372      $article = ArticlePeer::retrieveByPK($this->getRequestParameter('id')); 
     373      $this->forward404If(!$article); 
     374    } 
     375 
     376    // So is this one 
     377    public function executeShow() 
     378    { 
     379      $article = ArticlePeer::retrieveByPK($this->getRequestParameter('id')); 
     380      $this->forward404Unless($article); 
     381    } 
     382 
     383Using these methods will not only keep your code short, but it will also make it more readable. 
     384 
     385>**TIP** 
     386>When the action calls forward404() or its fellow methods, symfony throws an sfError404Exception that manages the 404 response. This means that if you need to display a 404 message from somewhere where you don't want to access the controller, you can just throw a similar exception. 
     387 
     388### Repeating Code for Several Actions of a Module 
     389 
     390The convention to name actions `executeActionName()` (in the case of an `sfActions` class) or execute() (in the case of an sfAction class) guarantees that symfony will find the action method. It gives you the ability to add other methods of your own that will not be considered as actions, as long as they don't start with `execute`. 
     391 
     392There is another useful convention for when you need to repeat several statements in each action before the actual action execution. You can then extract them into the `preExecute()` method of your action class. You can probably guess how to repeat statements after every action is executed: wrap them in a `postExecute()` method. The syntax of these methods is shown in Listing 6-14. 
     393 
     394Listing 6-14 - Using `preExecute`, `postExecute`, and Custom Methods in an Action Class 
     395 
     396    [php] 
     397    class mymoduleActions extends sfActions 
     398    { 
     399      public function preExecute() 
     400      { 
     401        // The code inserted here is executed at the beginning of each action call 
     402        ... 
     403      } 
     404 
     405      public function executeIndex() 
     406      { 
     407        ... 
     408      } 
     409 
     410      public function executeList() 
     411      { 
     412        ... 
     413        $this->myCustomMethod();  // Methods of the action class are accessible 
     414      } 
     415 
     416      public function postExecute() 
     417      { 
     418        // The code inserted here is executed at the end of each action call 
     419        ... 
     420      } 
     421 
     422      protected function myCustomMethod() 
     423      { 
     424        // You can also add your own methods, as long as they don't start with "execute" 
     425        // In that case, it's better to declare them as protected or private 
     426        ... 
     427      } 
     428    } 
     429 
     430Accessing the Request 
     431--------------------- 
     432 
     433You're familiar with the `getRequestParameter('myparam')` method, used to retrieve the value of a request parameter by its name. As a matter of fact, this method is a proxy for a chain of calls to the request's parameter holder `getRequest()->getParameter('myparam')`. The action class has access to the request object, called `sfWebRequest` in symfony, and to all its methods, via the `getRequest()` method. Table 6-1 lists the most useful `sfWebRequest` methods. 
     434 
     435Table 6-1.  Methods of the `sfWebRequest` Object 
     436Name  Function  Sample Output 
     437Request Information 
     438 
     439`getMethod()` 
     440 
     441Request method 
     442 
     443Returns `sfRequest::GET` or `sfRequest::POST` constants 
     444 
     445`getMethodName()` 
     446 
     447Request method name 
     448 
     449`'POST'` 
     450 
     451`getHttpHeader('Server')` 
     452 
     453Value of a given HTTP header 
     454 
     455`'Apache/2.0.59 (Unix) DAV/2 PHP/5.1.6'` 
     456 
     457`getCookie('foo')` 
     458 
     459Value of a named cookie 
     460 
     461`'bar'` 
     462 
     463`isXmlHttpRequest()`* 
     464 
     465Is it an Ajax request? 
     466 
     467`true` 
     468 
     469`isSecure()` 
     470 
     471Is it an SSL request? 
     472 
     473`true` 
     474 
     475Request Parameters 
     476 
     477`hasParameter('foo')` 
     478 
     479Is a parameter present in the request? 
     480 
     481`true` 
     482 
     483`getParameter('foo')` 
     484 
     485Value of a named parameter 
     486 
     487`'bar'` 
     488 
     489`getParameterHolder()->getAll()` 
     490 
     491Array of all request parameters 
     492 
     493URI-Related Information 
     494 
     495`getUri()` 
     496 
     497Full URI 
     498 
     499`'http://localhost/myapp_dev.php/mymodule/myaction'` 
     500 
     501`getPathInfo()` 
     502 
     503Path info 
     504 
     505`'/mymodule/myaction'` 
     506 
     507`getReferer()`** 
     508 
     509Referrer 
     510 
     511`'http://localhost/myapp_dev.php/'` 
     512 
     513`getHost()` 
     514 
     515Host name 
     516 
     517`'localhost'` 
     518 
     519`getScriptName()` 
     520 
     521Front controller path and name 
     522 
     523`'myapp_dev.php'` 
     524 
     525Client Browser Information 
     526 
     527`getLanguages()` 
     528 
     529Array of accepted languages 
     530 
     531`Array( ` ` [0] => fr ` ` [1] => fr_FR ` ` [2] => en_US ` ` [3] => en )` 
     532 
     533`getCharsets()` 
     534 
     535Array of accepted charsets 
     536 
     537`Array( ` ` [0] => ISO-8859-1 ` ` [1] => UTF-8 ` ` [2] => * )` 
     538 
     539getAcceptableContentType() 
     540 
     541Array of accepted content types 
     542 
     543`Array( [0] => text/xml [1] => text/html` 
     544 
     545*Works only with prototype **Sometimes blocked by proxies 
     546 
     547The `sfActions` class offers a few proxies to access the request methods more quickly, as shown in Listing 6-15. 
     548 
     549Listing 6-15 - Accessing the `sfRequest` Object Methods from an Action 
     550 
     551    [php] 
     552    class mymoduleActions extends sfActions 
     553    { 
     554      public function executeIndex() 
     555      { 
     556        $hasFoo = $this->getRequest()->hasParameter('foo'); 
     557        $hasFoo = $this->hasRequestParameter('foo');  // Shorter version 
     558        $foo     = $this->getRequest()->getParameter('foo'); 
     559        $foo     = $this->getRequestParameter('foo');  // Shorter version 
     560      } 
     561    } 
     562 
     563For multipart requests to which users attach files, the `sfWebRequest` object provides a means to access and move these files, as shown in Listing 6-16. 
     564 
     565Listing 6-16 - The `sfWebRequest` Object Knows How to Handle Attached Files 
     566 
     567    [php] 
     568    class mymoduleActions extends sfActions 
     569    { 
     570      public function executeUpload() 
     571      { 
     572        if ($this->getRequest()->hasFiles()) 
     573        { 
     574          foreach ($this->getRequest()->getFileNames() as $fileName) 
     575          { 
     576            $fileSize  = $this->getRequest()->getFileSize($fileName); 
     577            $fileType  = $this->getRequest()->getFileType($fileName); 
     578            $fileError = $this->getRequest()->hasFileError($fileName); 
     579            $uploadDir = sfConfig::get('sf_upload_dir'); 
     580            $this->getRequest()->moveFile('file', $uploadDir.'/'.$fileName); 
     581          } 
     582        } 
     583      } 
     584    } 
     585 
     586You don't have to worry about whether your server supports the `$_SERVER` or the `$_ENV` variables, or about default values or server-compatibility issues--the `sfWebRequest` methods do it all for you. Besides, their names are so evident that you will no longer need to browse the PHP documentation to find out how to get information from the request. 
     587 
     588User Session 
     589------------ 
     590 
     591Symfony automatically manages user sessions and is able to keep persistent data between requests for users. It uses the built-in PHP session-handling mechanisms and enhances them to make them more configurable and easier to use. 
     592 
     593### Accessing the User Session 
     594 
     595The session object for the current user is accessed in the action with the `getUser()` method and is an instance of the `sfUser` class. This class contains a parameter holder that allows you to store any user attribute in it. This data will be available to other requests until the end of the user session, as shown in Listing 6-17. User attributes can store any type of data (strings, arrays, and associative arrays). They can be set for every individual user, even if that user is not identified. 
     596 
     597Listing 6-17 - The `sfUser` Object Can Hold Custom User Attributes Existing Across Requests 
     598 
     599    [php] 
     600    class mymoduleActions extends sfActions 
     601    { 
     602      public function executeFirstPage() 
     603      { 
     604        $nickname = $this->getRequestParameter('nickname'); 
     605 
     606        // Store data in the user session 
     607        $this->getUser()->setAttribute('nickname', $nickname); 
     608      } 
     609 
     610      public function executeSecondPage() 
     611      { 
     612        // Retrieve data from the user session with a default value 
     613        $nickname = $this->getUser()->getAttribute('nickname', 'Anonymous Coward'); 
     614      } 
     615    } 
     616 
     617>**CAUTION** 
     618>You can store objects in the user session, but it is strongly discouraged. This is because the session object is serialized between requests and stored in a file. When the session is deserialized, the class of the stored objects must already be loaded, and that's not always the case. In addition, there can be "stalled" objects if you store Propel objects. 
     619 
     620Like many getters in symfony, the `getAttribute()` method accepts a second argument, specifying the default value to be used when the attribute is not defined. To check whether an attribute has been defined for a user, use the `hasAttribute()` method. The attributes are stored in a parameter holder that can be accessed by the `getAttributeHolder()` method. It allows for easy cleanup of the user attributes with the usual parameter holder methods, as shown in Listing 6-18. 
     621 
     622Listing 6-18 - Removing Data from the User Session 
     623 
     624    [php] 
     625    class mymoduleActions extends sfActions 
     626    { 
     627      public function executeRemoveNickname() 
     628      { 
     629        $this->getUser()->getAttributeHolder()->remove('nickname'); 
     630      } 
     631 
     632      public function executeCleanup() 
     633      { 
     634        $this->getUser()->getAttributeHolder()->clear(); 
     635      } 
     636    } 
     637 
     638The user session attributes are also available in the templates by default via the `$sf_user` variable, which stores the current `sfUser` object, as shown in Listing 6-19. 
     639 
     640Listing 6-19 - Templates Also Have Access to the User Session Attributes 
     641 
     642    [php] 
     643    <p> 
     644      Hello, <?php echo $sf_user->getAttribute('nickname') ?> 
     645    </p> 
     646 
     647>**NOTE** 
     648>If you need to store information just for the duration of the current request--for instance, to pass information through a chain of action calls--you may prefer the `sfRequest` class, which also has `getAttribute()` and `setAttribute()` methods. Only the attributes of the `sfUser` object are persistent between requests. 
     649 
     650### Flash Attributes 
     651 
     652A recurrent problem with user attributes is the cleaning of the user session once the attribute is not needed anymore. For instance, you may want to display a confirmation after updating data via a form. As the form-handling action makes a redirect, the only way to pass information from this action to the action it redirects to is to store the information in the user session. But once the confirmation message is displayed, you need to clear the attribute; otherwise, it will remain in the session until it expires. 
     653 
     654The flash attribute is an ephemeral attribute that you can define and forget, knowing that it will disappear after the very next request and leave the user session clean for the future. In your action, define the flash attribute like this: 
     655 
     656    [php] 
     657    $this->setFlash('attrib', $value); 
     658 
     659The template will be rendered and delivered to the user, who will then make a new request to another action. In this second action, just get the value of the flash attribute like this: 
     660 
     661    [php] 
     662    $value = $this->getFlash('attrib'); 
     663 
     664Then forget about it. After delivering this second page, the `attrib` flash attribute will be flushed. And even if you don't require it during this second action, the flash will disappear from the session anyway. 
     665 
     666If you need to access a flash attribute from a template, use the `$sf_flash` object: 
     667 
     668    [php] 
     669    <?php if ($sf_flash->has('attrib')): ?> 
     670      <?php echo $sf_flash->get('attrib') ?> 
     671    <?php endif; ?> 
     672 
     673or just: 
     674 
     675    [php] 
     676    <?php echo $sf_flash->get('attrib') ?> 
     677 
     678Flash attributes are a clean way of passing information to the very next request. 
     679 
     680### Session Management 
     681 
     682Symfony's session-handling feature completely masks the client and server storage of the session IDs to the developer. However, if you want to modify the default behaviors of the session-management mechanisms, it is still possible. This is mostly for advanced users. 
     683 
     684On the client side, sessions are handled by cookies. The symfony session cookie is called `symfony`, but you can change its name by editing the `factories.yml` configuration file, as shown in Listing 6-20. 
     685 
     686Listing 6-20 - Changing the Session Cookie Name, in `apps/myapp/config/factories.yml` 
     687 
     688    all: 
     689      storage: 
     690        class: sfSessionStorage 
     691        param: 
     692          session_name: my_cookie_name 
     693 
     694>**TIP** 
     695>The session is started (with the PHP function `session_start()`) only if the `auto_start` parameter is set to true in factories.yml (which is the case by default). If you want to start the user session manually, disable this setting of the storage factory. 
     696 
     697Symfony's session handling is based on PHP sessions. This means that if you want the client-side management of sessions to be handled by URL parameters instead of cookies, you just need to change the use_trans_sid setting in your php.ini. Be aware that this is not recommended. 
     698 
     699    session.use_trans_sid = 1 
     700 
     701On the server side, symfony stores user sessions in files by default. You can store them in your database by changing the value of the `class` parameter in `factories.yml`, as shown in Listing 6-21. 
     702 
     703Listing 6-21 - Changing the Server Session Storage, in `apps/myapp/config/factories.yml` 
     704 
     705    all: 
     706      storage: 
     707        class: sfMySQLSessionStorage 
     708        param: 
     709          db_table: SESSION_TABLE_NAME      # Name of the table storing the sessions 
     710          database: DATABASE_CONNECTION     # Name of the database connection to use 
     711 
     712The available session storage classes are `sfMySQLSessionStorage`, `sfPostgreSQLSessionStorage`, and `sfPDOSessionStorage`; the latter is preferred. The optional `database` setting defines the database connection to be used; symfony will then use `databases.yml` (see Chapter 8) to determine the connection settings (host, database name, user, and password) for this connection. 
     713 
     714Session expiration occurs automatically after sf_timeout seconds. This constant is 30 minutes by default and can be modified for each environment in the `settings.yml` configuration file, as shown in Listing 6-22. 
     715 
     716Listing 6-22 - Changing Session Lifetime, in `apps/myapp/config/settings.yml` 
     717 
     718    default: 
     719      .settings: 
     720        timeout:     1800           # Session lifetime in seconds 
     721 
     722Action Security 
     723--------------- 
     724 
     725The ability to execute an action can be restricted to users with certain privileges. The tools provided by symfony for this purpose allow the creation of secure applications, where users need to be authenticated before accessing some features or parts of the application. Securing an application requires two steps: declaring the security requirements for each action and logging in users with privileges so that they can access these secure actions. 
     726 
     727### Access Restriction 
     728 
     729Before being executed, every action passes by a special filter that checks if the current user has the privileges to access the requested action. In symfony, privileges are composed of two parts: 
     730 
     731  * Secure actions require users to be authenticated. 
     732  * Credentials are named security privileges that allow organizing security by group. 
     733 
     734Restricting access to an action is simply made by creating and editing a YAML configuration file called `security.yml` in the module `config/` directory. In this file, you can specify the security requirements that users must fulfill for each action or for `all` actions. Listing 6-23 shows a sample `security.yml`. 
     735 
     736Listing 6-23 - Setting Access Restrictions, in `apps/myapp/modules/mymodule/config/security.yml` 
     737 
     738    read: 
     739      is_secure:   off       # All users can request the read action 
     740 
     741    update: 
     742      is_secure:   on        # The update action is only for authenticated users 
     743 
     744    delete: 
     745      is_secure:   on        # Only for authenticated users 
     746      credentials: admin     # With the admin credential 
     747 
     748    all: 
     749      is_secure:  off        # off is the default value anyway 
     750 
     751Actions are not secure by default, so when there is no `security.yml` or no mention of an action in it, actions are accessible by everyone. If there is a `security.yml`, symfony looks for the name of the requested action and, if it exists, checks the fulfillment of the security requirements. What happens when a user tries to access a restricted action depends on his credentials: 
     752 
     753  * If the user is authenticated and has the proper credentials, the action is executed. 
     754  * If the user is not identified, he will be redirected to the default login action. 
     755  * If the user is identified but doesn't have the proper credentials, he will be redirected to the default secure action, shown in Figure 6-1. 
     756 
     757The default login and secure pages are pretty simple, and you will probably want to customize them. You can configure which actions are to be called in case of insufficient privileges in the application `settings.yml` by changing the value of the properties shown in Listing 6-24. 
     758 
     759![][8] 
     760 
     761   [8]: 
     762 
     763Figure 6-1 - The default secure action page 
     764 
     765Listing 6-24 - Default Security Actions Are Defined in `apps/myapp/config/security.yml` 
     766 
     767    all: 
     768      .actions: 
     769        login_module:           default 
     770        login_action:           login 
     771 
     772        secure_module:          default 
     773        secure_action:          secure 
     774 
     775### Granting Access 
     776 
     777To get access to restricted actions, users need to be authenticated and/or to have certain credentials. You can extend a user's privileges by calling methods of the `sfUser` object. The authenticated status of the user is set by the `setAuthenticated()` method. Listing 6-25 shows a simple example of user authentication. 
     778 
     779Listing 6-25 - Setting the Authenticated Status of a User 
     780 
     781    [php] 
     782    class myAccountActions extends sfActions 
     783    { 
     784      public function executeLogin() 
     785      { 
     786        if ($this->getRequestParameter('login') == 'foobar') 
     787        { 
     788          $this->getUser()->setAuthenticated(true); 
     789        } 
     790      } 
     791 
     792      public function executeLogout() 
     793      { 
     794        $this->getUser()->setAuthenticated(false); 
     795      } 
     796    } 
     797 
     798Credentials are a bit more complex to deal with, since you can check, add, remove, and clear credentials. Listing 6-26 describes the credential methods of the `sfUser` class. 
     799 
     800Listing 6-26 - Dealing with User Credentials in an Action 
     801 
     802    [php] 
     803    class myAccountActions extends sfActions 
     804    { 
     805      public function executeDoThingsWithCredentials() 
     806      { 
     807        $user = $this->getUser(); 
     808 
     809        // Add one or more credentials 
     810        $user->addCredential('foo'); 
     811        $user->addCredentials('foo', 'bar'); 
     812 
     813        // Check if the user has a credential 
     814        echo $user->hasCredential('foo');                     =>   true 
     815 
     816        // Check if the user has one of the credentials 
     817        echo $user->hasCredential(array('foo', 'bar'));       =>   true 
     818 
     819        // Check if the user has both credentials 
     820        echo $user->hasCredential(array('foo', 'bar'), true); =>   true 
     821 
     822        // Remove a credential 
     823        $user->removeCredential('foo'); 
     824        echo $user->hasCredential('foo');                     =>   false 
     825 
     826        // Remove all credentials (useful in the logout process) 
     827        $user->clearCredentials(); 
     828        echo $user->hasCredential('bar');                     =>   false 
     829      } 
     830    } 
     831 
     832If a user has the `'foo'` credential, that user will be able to access the actions for which the `security.yml` requires that credential. Credentials can also be used to display only authorized content in a template, as shown in Listing 6-27. 
     833 
     834Listing 6-27 - Dealing with User Credentials in a Template 
     835 
     836    [php] 
     837    <ul> 
     838      <li><?php echo link_to('section1', 'content/section1') ?></li> 
     839      <li><?php echo link_to('section2', 'content/section2') ?></li> 
     840      <?php if ($sf_user->hasCredential('section3')): ?> 
     841      <li><?php echo link_to('section3', 'content/section3') ?></li> 
     842      <?php endif; ?> 
     843    </ul> 
     844 
     845As for the authenticated status, credentials are often given to users during the login process. This is why the `sfUser` object is often extended to add login and logout methods, in order to set the security status of users in a central place. 
     846 
     847>**TIP** 
     848>Among the symfony plug-ins, the `sfGuardPlugin` extends the session class to make login and logout easy. Refer to Chapter 17 for more information. 
     849 
     850### Complex Credentials 
     851 
     852The YAML syntax used in the security.yml file allows you to restrict access to users having a combination of credentials, using either AND-type or OR-type associations. With such a combination, you can build a complex workflow and user privilege management system--for instance, a content management system (CMS) back-office accessible only to users with the admin credential, where articles can be edited only by users with the `editor` credential and published only by the ones with the `publisher` credential. Listing 6-28 shows this example. 
     853 
     854Listing 6-28 - Credentials Combination Syntax 
     855 
     856    editArticle: 
     857      credentials: [ admin, editor ]              # admin AND editor 
     858 
     859    publishArticle: 
     860      credentials: [ admin, publisher ]           # admin AND publisher 
     861 
     862    userManagement: 
     863      credentials: < admin, superuser >         # admin OR superuser 
     864 
     865Each time you add a new level of square brackets, the logic swaps between AND and OR. So you can create very complex credential combinations, such as this: 
     866 
     867    credentials: , accounts]] 
     868                 # root OR (supplier AND (owner OR quasiowner)) OR accounts 
     869 
     870Validation and Error-Handling Methods 
     871------------------------------------- 
     872 
     873Validating the action input--mostly request parameters--is a repetitive and tedious task. Symfony offers a built-in request validation system, using methods of the action class. 
     874 
     875Let's start with an example. When a user makes a request for `myAction`, symfony always looks for a method called `validateMyAction()` first. If it is found, then symfony executes it. The return value of this validation method determines the next method to be executed: if it returns `true`, then `executeMyAction()` is executed; otherwise, `handleErrorMyAction()` is executed. And, if in the latter case, handleErrorMyAction() doesn't exist, symfony looks for a generic handleError() method. If that doesn't exist either, it simply returns `sfView::ERROR` to render the `myActionError. php` template. Figure 6-2 depicts this process. 
     876 
     877![][9] 
     878 
     879   [9]: 
     880 
     881Figure 6-2 - The validation process 
     882 
     883So the key to validation is to respect the naming conventions for the action methods: 
     884 
     885  * `validateActionName` is the validation method, returning `true` or `false`. It is the first method looked for when the action `ActionName` is requested. If it doesn't exist, the action method is executed directly. 
     886  * `hand`leErrorActionName is the method called when the validation method fails. If it doesn't exist, the `Error` template is displayed. 
     887  * `executeActionName` is the action method. It must exist for all actions. 
     888 
     889Listing 6-29 shows an example of an action class with validation methods. Whether the validation passes or fails in this example, the `myActionSuccess.php` template will be executed, but not with the same parameters. 
     890 
     891Listing 6-29 - Sample Validation Methods 
     892 
     893    [php] 
     894    class mymoduleActions extends sfActions 
     895    { 
     896      public function validateMyAction() 
     897      { 
     898        return ($this->getRequestParameter('id') > 0); 
     899      } 
     900 
     901      public function handleErrorMyAction() 
     902      { 
     903        $this->message = "Invalid parameters"; 
     904 
     905        return sfView::SUCCESS; 
     906      } 
     907 
     908      public function executeMyAction() 
     909      { 
     910        $this->message = "The parameters are correct"; 
     911      } 
     912    } 
     913 
     914You can put any code you want in the `validate()` methods. Just make sure they return either `true` or `false`. As it is a method of the `sfActions` class, it has access to the `sfRequest` and `sfUser` objects as well, which can be really useful for input and context validation. 
     915 
     916You could use this mechanism to implement form validation (that is, control the values entered by the user in a form before processing it), but this is the type of repetitive task for which symfony provides automated tools, as described in Chapter 10. 
     917 
     918Filters 
     919------- 
     920 
     921The security process can be understood as a filter by which all requests must pass before executing the action. According to some tests executed in the filter, the processing of the request is modified--for instance, by changing the action executed (default/secure instead of the requested action in the case of the security filter). Symfony extends this idea to filter classes. You can specify any number of filter classes to be executed before the action execution or before the response rendering, and do this for every request. You can see filters as a way to package some code, similar to `preExecute()` and `postExecute()`, but at a higher level (for a whole application instead of for a whole module). 
     922 
     923### The Filter Chain 
     924 
     925Symfony actually sees the processing of a request as a chain of filters. When a request is received by the framework, the first filter (which is always the `sfRenderingFilter`) is executed. At some point, it calls the next filter in the chain, then the next, and so on. When the last filter (which is always `sfExecutionFilter`) is executed, the previous filter can finish, and so on back to the rendering filter. Figure 6-3 illustrates this idea with a sequence diagram, using an artificially small filter chain (the real one contains more filters). 
     926 
     927![][10] 
     928 
     929   [10]: 
     930 
     931Figure 6-3 - Sample filter chain 
     932 
     933This process justifies the structure of the filter classes. They all extend the `sfFilter` class, and contain one `execute()` method, expecting a `$filterChain` object as parameter. Somewhere in this method, the filter passes to the next filter in the chain by calling $filterChain->execute(). See Listing 6-30 for an example. So basically, filters are divided into two parts: 
     934 
     935  * The code before the call to $filterChain->execute() executes before the action execution. 
     936  * The code after the call to `$filterChain->execute()` executes after the action execution and before the rendering. 
     937 
     938Listing 6-30 - Filter Class Struture 
     939 
     940    [php] 
     941    class myFilter extends sfFilter 
     942    { 
     943      public function execute ($filterChain) 
     944      { 
     945        // Code to execute before the action execution 
     946        ... 
     947 
     948        // Execute next filter in the chain 
     949        $filterChain->execute(); 
     950 
     951        // Code to execute after the action execution, before the rendering 
     952        ... 
     953      } 
     954    } 
     955 
     956The default filter chain is defined in an application configuration file called `filters.yml`, and is shown in Listing 6-31. This file lists the filters that are to be executed for every request. 
     957 
     958Listing 6-31 - Default Filter Chain, in `myapp/config/filters.yml` 
     959 
     960    rendering: ~ 
     961    web_debug: ~ 
     962    security:  ~ 
     963 
     964    # Generally, you will want to insert your own filters here 
     965 
     966    cache:     ~ 
     967    common:    ~ 
     968    flash:     ~ 
     969    execution: ~ 
     970 
     971These declarations have no parameter (the tilde character, `~`, means "null" in YAML), because they inherit the parameters defined in the symfony core. In the core, symfony defines `class` and `param` settings for each of these filters. For instance, Listing 6-32 shows the default parameters for the `rendering` filter. 
     972 
     973Listing 6-32 - Default Parameters of the rendering Filter, in $sf_symfony_data_dir/config/filters.yml 
     974 
     975    rendering: 
     976      class: sfRenderingFilter   # Filter class 
     977      param:                     # Filter parameters 
     978        type: rendering 
     979 
     980By leaving the empty value (`~`) in the application `filters.yml`, you tell symfony to apply the filter with the default settings defined in the core. 
     981 
     982You can customize the filter chain in various ways: 
     983 
     984  * Disable some filters from the chain by adding an `enabled: off` parameter. For instance, to disable the web debug filter, write: 
     985 
     986    web_debug: 
     987      enabled: off 
     988 
     989  * Do not remove an entry from the `filters.yml` to disable a filter; symfony would throw an exception in this case. 
     990  * Add your own declarations somewhere in the chain (usually after the `security` filter) to add a custom filter (as discussed in the next section). Be aware that the `rendering` filter must be the first entry, and the `execution` filter must be the last entry of the filter chain. 
     991  * Override the default class and parameters of the default filters (notably to modify the security system and use your own security filter). 
     992 
     993![][11] 
     994 
     995   [11]: 
     996 
     997Tip  The `enabled: off` parameter works well to disable your own filters, but you can deactivate the default filters via the `settings.yml` file, by modifying the values of the `web_debug`, `use_security`, `cache`, and `use_flash` settings. This is because each of the default filters has a `condition` parameter that tests the value of these settings. 
     998 
     999![][12] 
     1000 
     1001   [12]: 
     1002 
     1003### Building Your Own Filter 
     1004 
     1005It is pretty simple to build a filter. Create a class definition similar to the one shown in Listing 6-30, and place it in one of the project's lib/ folders to take advantage of the autoloading feature. 
     1006 
     1007As an action can forward or redirect to another action and consequently relaunch the full chain of filters, you might want to restrict the execution of your own filters to the first action call of the request. The `isFirstCall()` method of the `sfFilter` class returns a Boolean for this purpose. This call only makes sense before the action execution. 
     1008 
     1009These concepts are clearer with an example. Listing 6-33 shows a filter used to auto-log users with a specific `MyWebSite` cookie, which is supposedly created by the login action. It is a rudimentary but working way to implement the "remember me" feature offered in login forms. 
     1010 
     1011Listing 6-33 - Sample Filter Class File, Saved in `apps/myapp/lib/rememberFilter.class.php` 
     1012 
     1013    [php] 
     1014    class rememberFilter extends sfFilter 
     1015    { 
     1016      public function execute($filterChain) 
     1017      { 
     1018        // Execute this filter only once 
     1019        if ($this->isFirstCall()) 
     1020        { 
     1021          // Filters don't have direct access to the request and user objects. 
     1022          // You will need to use the context object to get them 
     1023          $request = $this->getContext()->getRequest(); 
     1024          $user    = $this->getContext()->getUser(); 
     1025 
     1026          if ($request->getCookie('MyWebSite')) 
     1027          { 
     1028            // sign in 
     1029            $user->setAuthenticated(true); 
     1030          } 
     1031        } 
     1032 
     1033        // Execute next filter 
     1034        $filterChain->execute(); 
     1035      } 
     1036    } 
     1037 
     1038In some cases, instead of continuing the filter chain execution, you will need to forward to a specific action at the end of a filter. sfFilter doesn't have a forward() method, but sfController does, so you can simply do that by calling the following: 
     1039 
     1040    [php] 
     1041    return $this->getController()->forward('mymodule', 'myAction'); 
     1042 
     1043>**NOTE** 
     1044>The `sfFilter` class has an `initialize()` method, executed when the filter object is created. You can override it in your custom filter if you need to deal with filter parameters (defined in `filters.yml`, as described next) in your own way. 
     1045 
     1046### Filter Activation and Parameters 
     1047 
     1048Creating a filter file is not enough to activate it. You need to add your filter to the filter chain, and for that, you must declare the filter class in the `filters.yml`, located in the application or in the module `config/` directory, as shown in Listing 6-34. 
     1049 
     1050Listing 6-34 - Sample Filter Activation File, Saved in `apps/myapp/config/filters.yml` 
     1051 
     1052    rendering: ~ 
     1053    web_debug: ~ 
     1054    security:  ~ 
     1055 
     1056    remember:                 # Filters need a unique name 
     1057      class: rememberFilter 
     1058      param: 
     1059        cookie_name: MyWebSite 
     1060        condition:   %APP_ENABLE_REMEMBER_ME% 
     1061 
     1062    cache:     ~ 
     1063    common:    ~ 
     1064    flash:     ~ 
     1065    execution: ~ 
     1066 
     1067When activated, the filter is executed for each request. The filter configuration file can contain one or more parameter definitions under the `param` key. The filter class has the ability to get the value of these parameters with the getParameter() method. Listing 6-35 demonstrates how to get a filter parameter value. 
     1068 
     1069Listing 6-35 - Getting the Parameter Value, in `apps/myapp/lib/rememberFilter.class.php` 
     1070 
     1071    [php] 
     1072    class rememberFilter extends sfFilter 
     1073    { 
     1074      public function execute ($filterChain) 
     1075      { 
     1076          ... 
     1077          if ($request->getCookie($this->getParameter('cookie_name'))) 
     1078          ... 
     1079      } 
     1080    } 
     1081 
     1082The `condition` parameter is tested by the filter chain to see if the filter must be executed. So your filter declarations can rely on an application configuration, just like the one in Listing 6-34. The remember filter will be executed only if your application `app.yml` shows this: 
     1083 
     1084    all: 
     1085      enable_remember_me: on 
     1086 
     1087### Sample Filters 
     1088 
     1089The filter feature is useful to repeat code for every action. For instance, if you use a distant analytics system, you probably need to put a code snippet calling a distant tracker script in every page. You could put this code in the global layout, but then it would be active for all of the application. Alternatively, you could place it in a filter, such as the one shown in Listing 6-36, and activate it on a per-module basis. 
     1090 
     1091Listing 6-36 - Google Analytics Filter 
     1092 
     1093    [php] 
     1094    class sfGoogleAnalyticsFilter extends sfFilter 
     1095    { 
     1096      public function execute($filterChain) 
     1097      { 
     1098        // Nothing to do before the action 
     1099        $filterChain->execute(); 
     1100 
     1101        // Decorate the response with the tracker code 
     1102        $googleCode = ' 
     1103    <script src="http://www.google-analytics.com/urchin.js"  type="text/javascript"> 
     1104    </script> 
     1105    <script type="text/javascript"> 
     1106      _uacct="UA-'.$this->getParameter('google_id').'";urchinTracker(); 
     1107    </script>'; 
     1108        $response = $this->getContext()->getResponse(); 
     1109        $response->setContent(str_ireplace('</body>', $googleCode.'</body>',$response->getContent())); 
     1110       } 
     1111    } 
     1112 
     1113Be aware that this filter is not perfect, as it should not add the tracker on responses that are not HTML. 
     1114 
     1115Another example would be a filter that switches the request to SSL if it is not already, to secure the communication, as shown in Listing 6-37. 
     1116 
     1117Listing 6-37 - Secure Communication Filter 
     1118 
     1119    [php] 
     1120    class sfSecureFilter extends sfFilter 
     1121    { 
     1122      public function execute($filterChain) 
     1123      { 
     1124        $context = $this->getContext(); 
     1125        $request = $context->getRequest(); 
     1126        if (!$request->isSecure()) 
     1127        { 
     1128          $secure_url = str_replace('http', 'https', $request->getUri()); 
     1129          return $context->getController()->redirect($secure_url); 
     1130          // We don't continue the filter chain 
     1131        } 
     1132        else 
     1133        { 
     1134          // The request is already secure, so we can continue 
     1135          $filterChain->execute(); 
     1136        } 
     1137      } 
     1138    } 
     1139 
     1140Filters are used extensively in plug-ins, as they allow you to extend the features of an application globally. Refer to Chapter 17 to learn more about plug-ins, and see the online wiki (`http://www.symfony-project.com/trac/wiki`) for more filter examples. 
     1141 
     1142Module Configuration 
     1143-------------------- 
     1144 
     1145A few module behaviors rely on configuration. To modify them, you must create a `module.yml` file in the module's `config/` directory and define settings on a per-environment basis (or under the `all:` header for all environments). Listing 6-38 shows an example of a `module.yml` file for the `mymodule` module. 
     1146 
     1147Listing 6-38 - Module Configuration, in `apps/myapp/modules/mymodule/config/module.yml` 
     1148 
     1149    all:                 # For all environments 
     1150      enabled:     true 
     1151      is_internal: false 
     1152      view_name:   sfPhpView 
     1153 
     1154The enabled parameter allows you to disable all actions of a module. All actions are redirected to the module_disabled_module/module_disabled_action action (as defined in settings.yml). 
     1155 
     1156The is_internal parameter allows you to restrict the execution of all actions of a module to internal calls. For example, this is useful for mail actions that you must be able to call from another action, to send an e-mail message, but not from the outside. 
     1157 
     1158The view_name parameter defines the view class. It must inherit from sfView. Overriding this value allows you to use other view systems, with other templating engines, such as Smarty. 
     1159 
     1160Summary 
     1161------- 
     1162 
     1163In symfony, the controller layer is split into two parts: the front controller, which is the unique entry point to the application for a given environment, and the actions, which contain the page logic. An action has the ability to determine how its view will be executed, by returning one of the sfView constants. Inside an action, you can manipulate the different elements of the context, including the request object (sfRequest) and the current user session object (sfUser). 
     1164 
     1165Combining the power of the session object, the action object, and the security configuration provides a complete security system, with access restriction and credentials. Special validate() and handleError() methods in actions allow handling of request validation. And if the preExecute() and postExecute() methods are made for reusability of code inside a module, the filters authorize the same reusability for all the applications by making controller code executed for every request. 
     1166 
     1167}}} 
     1168 
     1169---- 
     1170[wiki:Documentation/ja_JP/ 目次]