I now have JsonReader as
/**
* @class Ext.data.JsonReader
* @extends Ext.data.DataReader
* Data reader class to create an Array of {@link Ext.data.Record} objects from a JSON response
* based on mappings in a provided {@link Ext.data.Record} constructor.<br>
* <p>
* Example code:
* <pre><code>
var Employee = Ext.data.Record.create([
{name: 'firstname'}, // map the Record's "firstname" field to the row object's key of the same name
{name: 'job', mapping: 'occupation'} // map the Record's "job" field to the row object's "occupation" key
]);
var myReader = new Ext.data.JsonReader(
{ // The metadata property, with configuration options:
totalProperty: "results", // the property which contains the total dataset size (optional)
root: "rows", // the property which contains an Array of row objects
idProperty: "id" // the property within each row object that provides an ID for the record (optional)
},
Employee // {@link Ext.data.Record} constructor that provides mapping for JSON object
);
</code></pre>
* <p>This would consume a JSON data object of the form:</p><pre><code>
{
results: 2, // Reader's configured totalProperty
rows: [ // Reader's configured root
{ id: 1, firstname: 'Bill', occupation: 'Gardener' }, // a row object
{ id: 2, firstname: 'Ben' , occupation: 'Horticulturalist' } // another row object
]
}
</code></pre>
* <p><b><u>Automatic configuration using metaData</u></b>
* <p>It is possible to change a JsonReader's metadata at any time by including a <b><tt>metaData</tt></b>
* property in the JSON data object. If the JSON data object has a <b><tt>metaData</tt></b> property, a
* {@link Ext.data.Store Store} object using this Reader will reconfigure itself to use the newly provided
* field definition and fire its {@link Ext.data.Store#metachange metachange} event. The metachange event
* handler may interrogate the <b><tt>metaData</tt></b> property to perform any configuration required.
* Note that reconfiguring a Store potentially invalidates objects which may refer to Fields or Records
* which no longer exist.</p>
* <p>The <b><tt>metaData</tt></b> property in the JSON data object may contain:</p>
* <div class="mdetail-params"><ul>
* <li>any of the configuration options for this class</li>
* <li>a <b><tt>{@link Ext.data.Record#fields fields}</tt></b> property which the JsonReader will
* use as an argument to the {@link Ext.data.Record#create data Record create method} in order to
* configure the layout of the Records it will produce.</li>
* <li>a <b><tt>{@link Ext.data.Store#sortInfo sortInfo}</tt></b> property which the JsonReader will
* use to set the {@link Ext.data.Store}'s {@link Ext.data.Store#sortInfo sortInfo} property</li>
* <li>any user-defined properties needed</li>
* </ul></div>
* <p>To use this facility to send the same data as the example above (without having to code the creation
* of the Record constructor), you would create the JsonReader like this:</p><pre><code>
var myReader = new Ext.data.JsonReader();
</code></pre>
* <p>The first data packet from the server would configure the reader by containing a
* <b><tt>metaData</tt></b> property <b>and</b> the data. For example, the JSON data object might take
* the form:</p>
<pre><code>
{
metaData: {
idProperty: 'id',
root: 'rows',
totalProperty: 'results',
fields: [
{name: 'name'},
{name: 'job', mapping: 'occupation'}
],
sortInfo: {field: 'name', direction:'ASC'}, // used by store to set its sortInfo
foo: 'bar' // custom property
},
results: 2,
rows: [
{ 'id': 1, 'name': 'Bill', occupation: 'Gardener' },
{ 'id': 2, 'name': 'Ben', occupation: 'Horticulturalist' }
]
}
</code></pre>
* @cfg {String} totalProperty Name of the property from which to retrieve the total number of records
* in the dataset. This is only needed if the whole dataset is not passed in one go, but is being
* paged from the remote server.
* @cfg {String} successProperty Name of the property from which to retrieve the success attribute used by forms.
* @cfg {String} root name of the property which contains the Array of row objects.
* @cfg {String} idProperty Name of the property within a row object that contains a record identifier value.
* @constructor
* Create a new JsonReader
* @param {Object} meta Metadata configuration options.
* @param {Object} recordType Either an Array of field definition objects as passed to
* {@link Ext.data.Record#create}, or a {@link Ext.data.Record Record} constructor created using {@link Ext.data.Record#create}.
*/
Ext.data.JsonReader = function(meta, recordType){
meta = meta || {};
Ext.data.JsonReader.superclass.constructor.call(this, meta, recordType || meta.fields);
};
Ext.extend(Ext.data.JsonReader, Ext.data.DataReader, {
dataPropertyName: 'jsonData',
idPropertyName: 'idProperty',
/**
* This JsonReader's metadata as passed to the constructor, or as passed in
* the last data packet's <b><tt>metaData</tt></b> property.
* @type Mixed
* @property meta
*/
/**
* After any data loads, the raw JSON data is available for further custom processing. If no data is
* loaded or there is a load exception this property will be undefined.
* @type Object
* @property jsonData
*/
/**
* This method is only used by a DataProxy which has retrieved data from a remote server.
* @param {Object} response The XHR object which contains the JSON data in its responseText.
* @return {Object} data A data block which is used by an Ext.data.Store object as
* a cache of Ext.data.Records.
*/
read : function(response){
var json = response.responseText;
var o = Ext.decode(json);
if(!o) {
throw {message: "JsonReader.read: Json object not found"};
}
return this.readRecords(o);
},
// private function a store will implement
onMetaChange : function(meta, recordType, o){
},
/**
* @ignore
*/
simpleAccess: function(obj, subsc) {
return obj[subsc];
},
/**
* @ignore
*/
getJsonAccessor: function(){
var re = /[\[\.]/;
return function(expr) {
try {
return(re.test(expr))
? new Function("obj", "return obj." + expr)
: function(obj){
return obj[expr];
};
} catch(e){}
return Ext.emptyFn;
};
}(),
/**
* Create a data block containing Ext.data.Records from a JSON object.
* @param {Object} o An object which contains an Array of row objects in the property specified
* in the config as 'root, and optionally a property, specified in the config as 'totalProperty'
* which contains the total size of the dataset.
* @return {Object} data A data block which is used by an Ext.data.Store object as
* a cache of Ext.data.Records.
*/
readRecords : function(o){
this[this.dataPropertyName] = o;
if(o.metaData){
delete this.ef;
this.meta = o.metaData;
this.recordType = Ext.data.Record.create(o.metaData.fields);
this.onMetaChange(this.meta, this.recordType, o);
}
var s = this.meta, Record = this.recordType,
f = Record.prototype.fields, fi = f.items, fl = f.length;
// Generate extraction functions for the total property, the success property, the root, the id, and for each field
if (!this.ef) {
this.ef = this.buildExtractors();
}
var root = this.getRoot(o), c = root.length, totalRecords = c, success = true;
if(this.getTotal){
var v = parseInt(this.getTotal(o), 10);
if(!isNaN(v)){
totalRecords = v;
}
}
if(this.getSuccess){
var v = this.getSuccess(o);
if(v === false || v === 'false'){
success = false;
}
}
var records = [];
for(var i = 0; i < c; i++){
var n = root[i];
var record = new Record(this.extractValues(n, fi, fl), this.getId(n));
record.json = n;
records[i] = record;
}
return {
success : success,
records : records,
totalRecords : totalRecords
};
},
// private
buildExtractors : function() {
var p, s = this.meta, Record = this.recordType,
f = Record.prototype.fields, fi = f.items, fl = f.length;
if(p = s.totalProperty) {
this.getTotal = this.getJsonAccessor(p);
}
if(p = s.successProperty) {
this.getSuccess = this.getJsonAccessor(p);
}
this.getRoot = s.root ? this.getJsonAccessor(s.root) : function(p){return p;};
if (p = (s.id || s[this.idPropertyName])) {
var g = this.getJsonAccessor(p);
this.getId = function(rec) {
var r = g(rec);
return (r === undefined || r === "") ? null : r;
};
} else {
this.getId = function(){return null;};
}
var ef = [];
for(var i = 0; i < fl; i++){
f = fi[i];
var map = (f.mapping !== undefined && f.mapping !== null) ? f.mapping : (this.useArray ? i : f.name);
ef.push(this.getJsonAccessor(map));
}
return ef;
},
// private extractValues
extractValues: function(data, items, len) {
var f, values = {};
for(var j = 0; j < len; j++){
f = items[j];
var v = this.ef[j](data);
values[f.name] = f.convert((v !== undefined) ? v : f.defaultValue, data);
}
return values;
},
/**
* readResponse
* decodes a json response from server
* @param {String} action [Ext.data.Api.actions.create|read|update|destroy]
* @param {Object} response
*/
readResponse : function(action, response) {
var json = response.responseText;
var o = Ext.decode(json);
if(!o) {
throw new Ext.data.JsonReader.Error('response', 'JsonReader.js');
}
if (Ext.isEmpty(o[this.meta.successProperty])) {
throw new Ext.data.JsonReader.Error('success', 'JsonReader.js', this.meta.successProperty);
}
// TODO, separate empty and undefined exceptions.
else if ((action == Ext.data.Api.actions.create || action == Ext.data.Api.actions.update) && Ext.isEmpty(o[this.meta.root])) {
throw new Ext.data.JsonReader.Error('root', 'JsonReader.js', this.meta.root);
}
// makde sure extaction functions are defined.
if (!this.ef) {
this.ef = this.buildExtractors();
}
return o;
}
});
/**
* Error class for JsonReader
*/
Ext.data.JsonReader.Error = Ext.extend(Ext.Error, {
cls : 'Ext.data.JsonReader',
render : function(id, file, data) {
switch (id) {
case 'response':
return "An error occurred while json-decoding your server response";
break;
case 'success':
return 'Could not locate your "successProperty" (' + data + ') in your server response. Please review your JsonReader config to ensure the config-property "successProperty" matches the property in your server-response. See the JsonReader docs.';
break;
case 'root':
return 'Could not locate your "root" property (' + data + ') in your server response. Please review your JsonReader config to ensure the config-property "root" matches the property your server-response. See the JsonReader docs.';
break;
}
}
});
So ArrayReader is just
Ext.data.ArrayReader = Ext.extend(Ext.data.JsonReader, {
/**
* @cfg {String} idProperty
* @hide
*/
/**
* @cfg {Number} id (optional) The subscript within row Array that provides an ID for the Record.
* Deprecated. Use {@link #idIndex} instead.
*/
/**
* @cfg {Number} idIndex (optional) The subscript within row Array that provides an ID for the Record.
*/
dataPropertyName: 'arrayData',
idPropertyName: 'idIndex',
useArray: true
});