public interface UserServiceAjaxRequest
The use of an Ajax callback implies to correctly handle the HTTP request and the HTTP response using JavaScript code.
The plain-text response generated by the callback is wrapped by EBX® in
specific XML content. Therefore, it is strongly advised to use the
provided JavaScript prototype EBX_AJAXResponseHandler
for
sending the request and handling the response.
This prototype defines the method sendRequest(urlToAjaxComponent)
for sending the Ajax request.
The URL to the Ajax callback can be generated by calling method
UserServiceResourceLocator.getURLForAjaxRequest(UserServiceAjaxRequest)
.
The following methods must be redefined and are mandatory in JavaScript
code that will use the EBX_AJAXResponseHandler
prototype.
handleAjaxResponseSuccess(responseContent)
:
this method defines the operations to perform if the Ajax
response has been generated successfully.
The parameter responseContent
contains the plain-text
response generated by this component.
handleAjaxResponseFailed(responseContent)
:
this method defines the operations to perform if the Ajax response
has failed, namely in case of a network error or server-side
exception.
The parameter responseContent
contains the plain-text
response generated by this component.
The following JavaScript example shows how to use this prototype:
// Definition of the custom Ajax handler MyAjaxHandler = function(anyParameters){ // Not mandatory, but for potential storage of parameters (e.g. an id of an HTML element) this.initialParameters = anyParameters; // This method is mandatory this.handleAjaxResponseSuccess = function(responseContent){ // Operations to perform if the Ajax response has been successfully generated. }; // This method is mandatory this.handleAjaxResponseFailed = function(responseContent){ // Operations to perform if the Ajax response has failed. }; }; // Specifies that the custom Ajax handler uses the prototype provided by EBX® MyAjaxHandler.prototype = new EBX_AJAXResponseHandler(); // Defines the function that sends the Ajax request. // This function can be attached to a JavaScript event (i.e. onclick, onkeydown, etc.). function callAjaxComponent(anyParameters, anyRequestParameter){ // Initializes the custom Ajax handler var myAjaxHandler = new MyAjaxHandler(anyParameters); // Some parameters can be added to the request, then retrieved on the server side usingUserServiceRequest.getParameter(String)
var requestParameter = "¶meter=" + anyRequestParameter; // Sends the request to the Ajax callback. // The URL to the Ajax component is obtained callingUserServiceResourceLocator.getURLForAjaxRequest(UserServiceAjaxRequest)
myAjaxHandler.sendRequest(urlToAjaxComponent + requestParameter); };
When the function sendRequest(urlToAjaxComponent)
is called,
the request is sent to the server and the callback method
processRequest(UserServiceAjaxContext, UserServiceAjaxResponse)
is called. The server sends the response from the Ajax component
to the client code, and the function handleAjaxResponseSuccess
or
handleAjaxResponseFailed
will automatically be called to
handle the response.
If the callback throws an exception, the exception's message will be added to
kernel.log
. On the client side, the method
handleAjaxResponseFailed(responseContent)
will be invoked.
Error, warning and info messages can also be added to the client-side message box by calling
UserServiceAjaxResponse.addMessage(UserMessage)
.
Modifier and Type | Method and Description |
---|---|
void |
processRequest(UserServiceAjaxContext anAjaxContext,
UserServiceAjaxResponse anAjaxResponse)
Processes the Ajax request and writes the response.
|
void processRequest(UserServiceAjaxContext anAjaxContext, UserServiceAjaxResponse anAjaxResponse)
anAjaxContext
- provides information on the request.anAjaxResponse
- the object to use to generate the response.