Chapter: Creating a response for a specific format
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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 the
responses/
application folder or also in the folderresponses/
of your own module. - 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(){
$this->_httpHeaders['Content-Type']='text/foo;charset='.jApp::config()->charset;
$this->sendHttpHeaders();
echo "content:\n".$this->content."/content;";
return true;
}
public function outputErrors(){
header('Content-Type: text/foo;charset='.jApp::config()->charset);
echo "errors\n";
foreach (jApp::coord()->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 closed to 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 or module.
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.
Here is an example of a response for your application :
[responses]
foo=myFooResponse
Here is an example of a response from your module :
[responses]
foo="mymodule~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.