Dojo ItemFileWriteStore not reading JSON server file - json

Question

I am using Dojo and it's dojo/data/ItemFileWriteStore module to read a JSON data file on my local server. In my .js file I have
var myDataStore = new ItemFileWriteStore({
url: "app/data/mydata.json",
handleAs: "json",
clearOnClose: true,
urlPreventCache: true
})
This is located in the postCreate function for my return declare function... so:
define([
"dojo/_base/declare",
"com/cayuse/base/_widget",
"dojo/text!./templates/myform.html",
...
"dojo/data/ItemFileWriteStore",
"dojo/store/DataStore",
"dojo/store/Observable",
"dojo/data/ObjectStore",
"dojo/domReady!"
],
function(declare, widget, template, ..., ItemFileWriteStore, DataStore,
Observable, ObjectStore){
return declare("app.myform", widget, {
templateString: template,
postCreate: function(){
domConstruct.create("link",{
type: "text/css",
rel: "stylesheet",
href: require.toUrl('dojox/form/resources/CheckedMultiSelect.css')
}, document.getElementsByTagName("head")[0]);
// data store
var myDataStore = new ItemFileWriteStore({
url: "app/data/mydata.json",
handleAs: "json",
clearOnClose: true,
urlPreventCache: true
})
console.log(myDataStore);
}
});
}
);
I can change the data store access from what you see above using IFWS method to
var myDataStore = dojo.xhrGet({
url: "app/data/mydata.json",
handleAs: "json",
load: function(data, ioArgs){
console.log(data);
}
});
and it finds the file with no problems.
This is so bizarre! Any ideas on what is going wrong here?
UPDATED:
Here is the data in the file I am reading. I believe it conforms to the JSON format. Let me know if not. xhrGet reads it fine.
{ "identifier": "id",
"label": "firstName",
"items":[
{"id":"0","firstName":"Robert","website":"www.barker.com","email":"robert#barker.com","bday":"1928-08-09","color":"Blue","toolkits":["Dojo","Moo"],"sendEmail":["on"],"format":"HTML"},
{"id":"1","firstName":"Vanna","website":"www.white.com","email":"vanna#white.com","bday":"1968-07-23","color":"Green","toolkits":["Dojo","jQuery"],"sendEmail":["off"],"format":"Text"}
]
}

Answer 1

ItemFileWriteStore requires your data being structured into something like this:
{ identifier: 'abbr',
label: 'name',
items: [
{ abbr:'ec', name:'Ecuador', capital:'Quito' },
{ abbr:'eg', name:'Egypt', capital:'Cairo' },
{ abbr:'sv', name:'El Salvador', capital:'San Salvador' },
{ abbr:'gq', name:'Equatorial Guinea', capital:'Malabo' },
{ abbr:'er', name:'Eritrea', capital:'Asmara' },
{ abbr:'ee', name:'Estonia', capital:'Tallinn' },
{ abbr:'et', name:'Ethiopia', capital:'Addis Ababa' }
]}
That is 'identifier' being your "ID" field, 'label' being your "label" field and then all your objects inside an array called "items".
You can check it out here in ItemFileWriteStore's documentation. If you don't have your JSON data structured like that it's possible that you may end up reading your file with the IFWS and actually not reading any data.
There are other store implementations in dojo 1.7 that don't require such structure, e.g. Memory Store that you can combine with other file reading techniques to achieve the same.

Answer 2

Try using dojo.data.ItemFileReadStore for reading
json data files, instead of dojo/data/ItemFileWriteStore.
Note that dojo.data.ItemFileWriteStore is used for writting json data.

Answer 3

If your code is EXACTLY as you posted it above then the interpreter might not like the fact that you omitted the semicolon from the ItemFileWriteStore assignment. Try adding the ';' as below:
// data store
var myDataStore = new ItemFileWriteStore({
url: "app/data/mydata.json",
handleAs: "json",
clearOnClose: true,
urlPreventCache: true
});
console.log(myDataStore);