Chapter: Generating content in an unsupported format
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Create a response ¶
If you have to deal with an unsupported format in Jelix, just create a new response.
You have to follow these steps:
- create a class inheriting from jResponse (or another existing response), and implementing methods to support your specific format.
- save this class in a file located under responses application folder.
- declare the new response type in configuration file and assign its alias.
Create a class ¶
A response class must declare at min two methods: output() and outputErrors(). And overload default value of $_type member with its specific response type. output() generates response content by means of call to print or echo. outputErrors is called if blocking errors are raised through action processing. A different response is then generated maybe respecting the specific format also. And do not forget to specify the format type in HTTP header.
Example (it's a totally funny format, of course):
class myFooResponse extends jResponse {
protected $_type = 'foo';
public $content = '';
/**
* generate content and send it to the client.
* @return boolean true if process is ok, false otherwise
*/
public function output(){
global $gJConfig;
$this->_httpHeaders['Content-Type']='text/foo;charset='.$gJConfig->charset;
$this->sendHttpHeaders();
echo "content:\n".$this->content."/content;";
return true;
}
public function outputErrors(){
global $gJConfig;
header('Content-Type: text/foo;charset='.$gJConfig->charset);
echo "errors\n";
foreach( $GLOBALS['gJCoord']->errorMessages as $e){
echo '['.$e[0].' '.$e[1].'] '.$e[2]." \t".$e[3]." \t".$e[4]."\n";
}
echo "/errors;";
}
}
As shown above, you can added any new member properties and methods to your response (such as $content) to deal with your format. But, jResponse defines an API that you can use by default: it instantiates a template, it has a title property for setting an HTML page title, it defines methods to fill the <head> block, etc. Dive into lib/jelix/response and pick a response to inherit if your format is close this existing response.
Class location ¶
there is no naming convention for your response class but it has to be repeated in class filename. In the example above, the class should live in a "myFooResponse.class.php" file under responses folder of your application.
Declare a response ¶
Last step, your new response must be declared and given an alias in configuration file. Just add this line alias=class in [responses] section of config.ini.php.
Example:
[responses]
foo=myFooResponse
Then in a controller, you can use myFooResponse:
function index(){
$rep = this->getResponse('foo');
$rep->content='hello world';
return $rep;
}
Note: Jelix uses aliases for responses. It allows to redefine transparently a response type and customize it. See common processes documentation.
About the use of templates ¶
In template, you have to use some plugins like functions. Template plugins are related to a specific type of response. So if you create a new response type, and if you want to reuse some existing plugins, you have to recreate some plugins for this type.
However, if your response object inherits from an existing response object (like jResponseHtml), you can use existing plugins in your template, unless you modify the value of the type property of the response object.
