Why do you say a redirect happens ? Does your page refresh when you
change the selectbox value ?
It won't refresh because all your doing is call a javascript function.
There's no redirect.
Britske wrote:
since your example effectively calls a ActionLink through AJAX, a redirect
DOES happen. It's the result of the ActionLink. If I'm seeing this correctly
what then is the advantage of doing a call through AJAX or a form.submit()
for the discussed purpose, since both result in a redirect?
//Geert-Jan
HugoPalma wrote:
The method i suggested is implemented so that you don't have to submit
the form. That's what AJAX is all about, you make a request to the
server and then update a portion of your page based on the response from
the server using javascript. There's no page reload of for submission.
Britske wrote:
yeah indeed it is only called once when the template is rendered, I
discovered now.
However i don't need to return a dynamic url or whatever based on the
getTheLink-method.
what I need is a way to reliably catch a event at the server/java side
(in
this case onChange) every time that event occurs. I don't want to submit
my
form when that happens (otherwise I could use the method you suggested)
but
I want to update some information on the current page and stay there.
This means that i have to redirect to my currentpage with a couple of
queryparameters in the url which depend on the selected fields in the
form.
hmm, the more i think about it, I don't think i really need to catch the
event server-side. I just redirect to the current page on onChange using
javascript:window.location=... and parse the querystrings correctly in
it.
hope this makes sense,
thanks!
Geert-Jan
HugoPalma wrote:
That's the way it's supposed to be.
You only see the getTheLink method executed once because that what it
need to replace ${theLink} in your template with the correct link that
is returned from your method. This is done once when the page renders.
If you look at the rendered page source you won't see ${theLink} there,
instead you will the the generated link to your listener.
Anyway, does it really matter how many times the getTheLink method is
invoked ? I think not. What really matters is that the listener method
to which your getTheLink method should be returning the URL to is called
whenever you call the "sendRequest" function.
Britske wrote:
thanks that works partially.
However, the event is only catched twice:
1. on pageload (??m the sendRequest isn't called, but somehow the
getTheLink()-method is executed.)
2. the first time i send a onchange.
However after the first onchange all other onchange-event don't get
getTheLink() executed, although sendRequest() is called on the
client-side
each time.
This is my relevant code:
in html:
<script>
function sendRequest()
{
alert("sendRequest reached");
new Ajax.Request('${theLink}',
{asynchronous:true,onSuccess:handleResponse});
}
</script>
...
<select t:type="select" t:model="themaList" t:value="thema"
onchange="sendRequest()" name="thema" id="thema" tabindex="4"
class="formElement"/>
in the page-class:
public String getTheLink()
{
System.out.println("catched!!");
return "catched!";
}
Do you 've got any idea what causes this behavior?
Thanks,
Geert-Jan
HugoPalma wrote:
I would suggest that you use AJAX instead of doing the form submit.
Although the AJAX integration in T5 is still not implemented it's very
easy to do using the provided prototype and json javascripts. I did
this
successfully for some simple events also.
Shortly, here's how i did it:
In my page i have these two javascript functions:
function handleResponse(xhrResponse) {
var json = xhrResponse.responseText.evalJSON(true);
//Do whatever you want with the server response
}
// -->
function sendRequest() {
new Ajax.Request('${theLink}', {asynchronous:true,
onSuccess:handleResponse});
}
On the page class i have:
public String getTheLink() {
Link l = _resources.createActionLink("myAction", false);
return l.toURI();
}
public StreamResponse onMyAction() {
Collection<Casta> castas =
_regiaoDao.getRegiao(regiao).getCastas();
JSONObject jsonObject = new JSONObject();
// Add whatever info you want to send to the client
return new TextStreamResponse("text/xml",
jsonObject.toString());
}
And that's it. Works great. All you have to do now is call the
sendRequest function from whatever javascript event you want to catch.
Hope this helps.
Britske wrote:
I have a use-case in which i need to catch a onchange of of
select-component
on the server-side.
The only way I know how to do that is do a javascript
onchange='this.form.submit()' and catch the onsubmit() event on the
serverside.
This works well when i don't have a submit-component in the form as
well.
However, when I do have a submit the onchange doesn't give a
onsubmit()
on
the serverside anymore.
So, the onchange in the following snippet doesn't give a server side
onsubmit()-event:
<body>
<form t:type="form" t:id="form" id="form">
<select t:type="select" t:model="countryList" t:value="country"
onchange="this.form.submit();"/>
<input t:type="Submit" value="All results"/>
</form>
</body>
However, the following does:
<body>
<form t:type="form" t:id="form" id="form">
<select t:type="select" t:model="countryList" t:value="country"
onchange="this.form.submit();"/>
<!--<input t:type="Submit" value="All results"/>-->
</form>
</body>
This isn't expected behavior since both examples do work with plain
html
form elements.
anyone?
Geert-Jan
