Re: Combining EXTJS with WebObjects.
Re: Combining EXTJS with WebObjects.
- Subject: Re: Combining EXTJS with WebObjects.
- From: Gustavo Pizano <email@hidden>
- Date: Fri, 4 Sep 2009 13:51:00 +0200
John Thanks for the reply.. let me digest it... hehehe..
Well I know EXT its heavy, but I see no other way to create such a grid, due my lack of knowledge in JS and the resquest-response loop, I need to check more theory then.
Ok so let me see If I understood after reading 3 times... and checking google what is JSON about... hehe,.. I ko about it, but I never worked with it.. I thought it was dead notation. :S.
So.
public WOActionResults handleRequest(WORequest request, WOContext context) {
will be invoked when form within the JS I will create a new XMLRequest() ? which as I think it's done by the prototype.js that uses the Ajax framework isn't? (Im jsut checking the JSONExample in the Ajax examples).
then it will look in the request a String with binding "data" and then convert it to a JSON object and place it in the response.
So here in this method is where I generate the list of objects I need to send and place it into a JSON object, put it in the respose and send back to the client.. isn't ?
Not clear:
1. the actionName... this comes from the parent? no... where is that binding?
2. JSONObject jsonResponse = (JSONObject) action.invoke(parent(), new
JSONObject(inputString)); .... what am I doing here?.
3/. What for do I need to get the String of "data" String inputString = request.stringFormValueForKey("data"); If when Im requesting it has nothing? I dunno.. im kinda confused here..
I dunno if the JSONExample that is there, does what Im trying to do here... and what you explain me... I see there is a AjaxProxy binding, and then simply they ask for data form the JS as var a = <name>. <proxyName>.method(). and then in the Application.java they register the service which in the example is a ExampleService?..
so I can do something like that but with my custom logic that return the data as an Object?
I dunno to many things in my mind,.. but if this what Im thinking its correct then my mind its getting clear.. I wish to learn more in depth how to do things.. but I will be reinventing the wheel... hehe .
G.
On Fri, Sep 4, 2009 at 12:47 PM, John Bruce
<email@hidden> wrote:
Hi Gustavo,
You can use the Wonder Ajax framework to get JSON data loaded so that
Ext can use it as a data store. The pricipal is to have a component
that generates a url which Ext can use as the remote address for a
JSON data store. A very rough example which is similar to the
AjaxProxy one is:
public class AjaxSimpleProxy extends AjaxComponent {
public String actionName;
public AjaxSimpleProxy(WOContext context) {
super(context);
}
@Override
public void reset() {
actionName = null;
super.reset();
}
@Override
protected void addRequiredWebResources(WOResponse response) {
}
@Override
public void appendToResponse(WOResponse response, WOContext context) {
//WOComponent component = context.component();
String actionUrl = AjaxUtils.ajaxComponentActionUrl(context);
response.appendContentString(actionUrl);
super.appendToResponse(response, context);
}
public String actionName() {
if (actionName == null) {
actionName = (String) valueForBinding("actionName");
}
return actionName;
}
@Override
public WOActionResults handleRequest(WORequest request, WOContext context) {
WOResponse response = AjaxUtils.createResponse(request, context);
String inputString = request.stringFormValueForKey("data");
if (log.isDebugEnabled()) {
log.debug("AjaxSimpleProxy.handleRequest: input = " + inputString);
}
NSSelector action = "" NSSelector(actionName(), new Class[] {
JSONObject.class } );
try {
JSONObject jsonResponse = (JSONObject) action.invoke(parent(), new
JSONObject(inputString));
response.setContent(jsonResponse.toString());
response.setHeader("application/json", "content-type");
} catch (Exception e) {
e.printStackTrace();
}
return response;
}
}
Basically the idea in this component is to bind the name of an action
in the parent component that accepts a JSONObject as the argument.
When rendering the main HTML response for that page this component
generates a url which when called will looked for a request paramater
called "data" which it expects to be JSON data. It will then turn that
into a JSON object and invoke a method in the parent component that
match the name of the "actionName" binding. It expects that this
method takes a JSONObject as the only parameter. In that method you
can do whatever you need but the return value should also be a
JSONObject and then that result is returned as the content of the
response.
This is a very basic component and is just to illustrate one way it
can be done. You would want to clean it up if you actually use it in
production. It doesn't do anything cleaver for you but can allow you
to send JSON data back and forth to a WOComponent from JS in your
page.
Other ways include creating a direct action to return the JSON data
for the EXT grid. This is simpler but has the problem that it is
outside your component.
Ext can be very heavy weight and require a lot of files to be
downloaded to the client browser. It's also likes things to be done in
the *Ext Way* which can sometimes be a pain. Although the widgets are
very nice... . It does work with WO but you do need to do a bit of
work.
HTH
John
On Fri, Sep 4, 2009 at 11:16 AM, Gustavo
Pizano<
email@hidden> wrote:
> Hello,.. Well after almost giving up on my requirement to put more than one
> column in a wobrowser to have multiple selections. I remind that before I
> did some little work with EXTJS. It has what we need. a GRID
> extjsComponent.. :D:D.. now how do I integrate WO and EXTJS?
> In the example of grid they are loading data from an array of arrays, and
> configuring "hard-coded" all the grid. How can I from the JS ask the WO
> server for the data to congifure the grid? is it possible?..
> another approach I saw was to generate a hidden WORepetition and generate
> all the data, then form the JS get the element and create the grid, but this
> approach I don't like it, becuase if I need another grid somewhere else I
> have to do all again, I want to reuse code.
> Another approach is to load the data form an xml, the same, grid has a url:
> attribute I fetch the xml there, so in th backend I will need to generate
> the xml, keep it there, while EXTJS via the url: ask for it.. what comes to
> my mind are security stuff... and some theoretical stuff like:
> How WO knows that the JS that its requesting is valid for the session in
> the WO application?.
> I think this is about the request-n-response loop... isn't it?
>
> So.. any advice... help, clue, light, code?
> G.
>
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