My problem is this: I'm having difficulty taking the JSON data I receive from a Servlet after transforming it from JSON text to a JSON Object and using it as a dojo.data.ItemFileReadStore data store in a dijit.form.FilteringSelect. Please see below for a detailed description of the problem.
Summary: Presently I'm working on a UI widget that will dynamically populate a dijit.form.FilteringSelect widget with data that is supplied from a database returned in an HTTP response object using the dojo.xhrGet() method. After struggling some to understand how things should be working I've successfully built up a JSON object in Java and returned it from the servlet in the HTTP response object.
The JSON text (a list of publications) looks like this coming from the servlet:
{"code":"01",
"runCodes":[{"name":"Mainsheet","codes":["MA"]}],
"name":"Publication1",
"id":1},
{"code":"02",
"runCodes":[{"name":"Mainsheet","codes":["MA"]}],
"name":"Publication2",
"id":2},
{"code":"03","runCodes":[{"name":"Mainsheet","codes":["MA"]}],
"name":"Publication3",
"id":3},
{"code":"04","runCodes":[{"name":"Mainsheet","codes":["MA"]}],
"name":"Publication4",
"id":4},
...
{"code":"99","runCodes":[{"name":"Mainsheet","codes":["MA"]}],
"name":"Publication99",
"id":99}
]
This seems to be in line with an acceptable format of data for parsing JSON as I transform the JSON text that comes from the servlet into an actual JSON object using JavaScript's eval() method just after I perform the xhrGet method (which, by the way is a synchronous, or blocking, request). The following code is a snippet of how I'm doing this:
url: 'path/to/Servlet',
handleAs: 'text',
content: {action: 'xhr'},
load: function(response, args) {
console.debug("Loading the XHR...");
return(response);
},
error: function(response, args) {
console.error("XML HTTP Request Error with [HTTP] status code: ", args.xhr.status);
return(response);
}};
var response = dojo.xhrGet(xhr);
this.publications = eval('(' + response.results[0] + ')');
My problem lies in using this JSON object to populate a data store to be used with a filtering select, the code I use to create the filtering select is as follows:
var dataStore = new dojo.data.ItemFileReadStore({data: jsonObj});
var fs = new dijit.form.FilteringSelect({name: 'publication', store: dataStore}, this.itemNode);
fs.startup();
But when the code attempts to execute the code to create the new FilteringSelect widget, I receive an error "arrayOfValues has no properties." I've narrowed it down and run a few test cases, the error seems to be because when creating the data store, all values are indexed within arrays, even if they are only one element--that being the case the system can't extract the proper value for identifier, and conceivably the label fields.
Is there any way around this, do I need to implement a new data store as an extension of the ItemFileReadStore class? I found some posts in the Dojo forums that might help me, but none that are specific to this issue so far as I could tell.
Reference posts:
Partial Resolution...?
Apparently part of my problem was that the JSON data needs to be a flat structure (without embedded arrays) or else the data store(s) have a problem processing the data in regards to "identifier" and "label" properties. This seems to be the resolution to the problem I was having.