[need help] Loading a TreePanel with C# webservice

[photoz]

I almost have this working, but am stuck getting proper JSON response from my C# webservice. I have been working off of this thread to get this far:
http://extjs.com/forum/showthread.ph...t=asp.net+json

Here is my JS:

            Ext.Ajax.on('beforerequest', function(conn, options){
	            conn.defaultHeaders = {'Content-Type': 'application/json; charset=utf-8'}
            });
var Tree = Ext.tree;
            
            var tree = new Tree.TreePanel('west-div', {
                animate:true,
                loader: new Tree.TreeLoader(),
                enableDD:true,
                containerScroll: true
            });
            
            var root = new Tree.AsyncTreeNode({
                text: 'Instrument',
                draggable: false,
                loader: new Tree.TreeLoader({
                    dataUrl:'../ws/Treeloading.asmx/GetNodes'
                }),
                id:'source'
            });
            tree.setRootNode(root);
            tree.render();
            root.expand();

Here is my WS (just test code for now):

[WebMethod]
    [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public TreeNode GetNodes() {
        TreeNode mynode = new TreeNode();
        mynode.id = "test";
        mynode.text = "Test node";
        mynode.leaf = true;
        mynode.cls = "file";

        //System.Web.Script.Serialization.JavaScriptSerializer js = new System.Web.Script.Serialization.JavaScriptSerializer();
        //return js.Serialize(mynode);
        return mynode;
    }

Currently, my WS is returning this output which is response type 'text/xml':

<?xml version="1.0" encoding="utf-8"?>

<TreeNode xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"

 xmlns="http://tempuri.org/">

  <text>Test node</text>

  <id>test</id>

  <leaf>true</leaf>

  <cls>file</cls>

</TreeNode>

Here are my ideas as to why this is failing:
When the TreeLoader calls the WS, it does a post and sets the content-type to (from Firebug):

Content-Type:application/x-www-form-urlencoded,application/json

You can see that the application/json is tacked on after the form encoding.

So it seems that sending form data in the request (and thus setting the incorrect Content-Type) is causing .NET to send back XML instead of JSON.

I can make a call to the WS via 'Atlas' just fine like so:

Treeloading.GetNodes(null, null ,null);

And this will return the proper JSON response:

{"__type":"TreeNode","text":"Test node","id":"test","leaf":true,"cls":"file"}

But the Atlas request has the proper Content-Type of only:

application/json; charset=utf-8

I'm stuck, could use some help. Thanks!

[photoz]

I have attached a project for testing, you will need to supply the ext-1.1 folder into the webroot.

If anyone can shed some light on how to get that webservice to spit out JSON instead of XML, I'd really appreciate it!

[photoz]

bump for some love.

[photoz]

From what I can tell, what is happening is that Ext is sending the request with the incorrect Content-Type. When I change the defaultHeaders to application/json, its still sending form-urlencoded in there with it.

This only seems to be happening with the TreePanel, because in this thread I was using to come up with this code, they were doing an HttpProxy and changing the defaultHeaders, which appears to work there.

Is this a possible bug with the TreePanel?

Still looking for some help on this. Thanks for your time.

[photoz]

I'll continue replying to myself, its fun and exciting.

I did manage to force Ext to force the Content-type to only be application/json.

            Ext.lib.Ajax.useDefaultHeader = false;
            Ext.Ajax.on('beforerequest', function(conn, options){
	            conn.defaultHeaders = {'Content-Type': 'application/json; charset=utf-8'}
            });

This got me half way there.

After doing that, the next problem is that the POST data that is sent (node=currentNode) is sent as a name-value pair and not in JSON format, which causes the C# webservice to 500 on the request.

So in the end I broke down and gave up on the webservice model and went with writing a *gasp* webpage that clears the response buffer, resets the content-type to application/json and sends back the JSON object.

This solution is not as elegant, but at this point, I just need something that freaking works.

If at some point in the future the TreeLoader can be made to make a JSON request as opposed to the traditional form-POST request, I could go back to the webservice model and let C# wrap my objects for me in JSON.

[MarcusGarvey'sGhost]

I am having exactly the same problem as well, having to now use Response Page model within .Net to get jason back which is a very horrible approach as I’m having to split my logic across two models. Would be handy if this get's fixed in an upcoming release. Many thanks guys.

[Vaevictus]

got the same problem.

would be nice if the treelaoder accepted config options such as

dataUrl: 'WebService.asmx/GetTreeNodes',
method: 'post',
jsonData: { somevar: somevalue },
headers: { 'Content-Type': 'application/json; charset=utf-8;' }

treeloaders ajax request is not consistent with the rest of extjs ajax requests

[Vaevictus]

This thread should be in the 3.x forum I think.......