/**
* @class Ext.data.XmlReader
* @extends Ext.data.DataReader
* <p>Data reader class to create an Array of {@link Ext.data.Record} objects from an XML document
* based on mappings in a provided {@link Ext.data.Record} constructor.</p>
* <p><b>Note</b>: that in order for the browser to parse a returned XML document, the Content-Type
* header in the HTTP response must be set to "text/xml" or "application/xml".</p>
* <p>Example code:</p>
* <pre><code>
var Employee = Ext.data.Record.create([
{name: 'name', mapping: 'name'}, // "mapping" property not needed if it is the same as "name"
{name: 'occupation'} // This field will use "occupation" as the mapping.
]);
var myReader = new Ext.data.XmlReader({
totalProperty: "results", // The element which contains the total dataset size (optional)
record: "row", // The repeated element which contains row information
idProperty: "id" // The element within the row that provides an ID for the record (optional)
messageProperty: "msg" // The element within the response that provides a user-feedback message (optional)
}, Employee);
</code></pre>
* <p>
* This would consume an XML file like this:
* <pre><code>
<?xml version="1.0" encoding="UTF-8"?>
<dataset>
<results>2</results>
<row>
<id>1</id>
<name>Bill</name>
<occupation>Gardener</occupation>
</row>
<row>
<id>2</id>
<name>Ben</name>
<occupation>Horticulturalist</occupation>
</row>
</dataset>
</code></pre>
* @cfg {String} totalProperty The DomQuery path 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} record The DomQuery path to the repeated element which contains record information.
* @cfg {String} successProperty The DomQuery path to the success attribute used by forms.
* @cfg {String} idPath The DomQuery path relative from the record element to the element that contains
* a record identifier value.
* @constructor
* Create a new XmlReader.
* @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 Record constructor object created using {@link Ext.data.Record#create}.
*/
Ext.data.XmlReader = function(meta, recordType){
meta = meta || {};
// backwards compat, convert idPath or id / success
Ext.applyIf(meta, {
idProperty: meta.idProperty || meta.idPath || meta.id,
successProperty: meta.successProperty || meta.success
});
Ext.data.XmlReader.superclass.constructor.call(this, meta, recordType || meta.fields);
};
Ext.extend(Ext.data.XmlReader, Ext.data.DataReader, {
/**
* 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 parsed XML document. The response is expected
* to contain a property called <tt>responseXML</tt> which refers to an XML document object.
* @return {Object} records A data block which is used by an {@link Ext.data.Store} as
* a cache of Ext.data.Records.
*/
read : function(response){
var doc = response.responseXML;
if(!doc) {
throw {message: "XmlReader.read: XML Document not available"};
}
return this.readRecords(doc);
},
/**
* Create a data block containing Ext.data.Records from an XML document.
* @param {Object} doc A parsed XML document.
* @return {Object} records A data block which is used by an {@link Ext.data.Store} as
* a cache of Ext.data.Records.
*/
readRecords : function(doc){
/**
* After any data loads/reads, the raw XML Document is available for further custom processing.
* @type XMLDocument
*/
this.xmlData = doc;
var root = doc.documentElement || doc,
q = Ext.DomQuery,
totalRecords = 0,
success = true;
if(this.meta.totalProperty){
totalRecords = this.getTotal(root, 0);
}
if(this.meta.successProperty){
success = this.getSuccess(root);
}
var records = this.extractData(q.select(this.meta.record, root), true); // <-- true to return Ext.data.Record[]
// TODO return Ext.data.Response instance. @see #readResponse
return {
success : success,
records : records,
totalRecords : totalRecords || records.length
};
},
/**
* Decode an XML response from server.
* @param {String} action [{@link Ext.data.Api#actions} create|read|update|destroy]
* @param {Object} response HTTP Response object from browser.
* @return {Ext.data.Response} An instance of {@link Ext.data.Response}
*/
readResponse : function(action, response) {
var q = Ext.DomQuery,
doc = response.responseXML,
root = doc.documentElement || doc;
// create general Response instance.
var res = new Ext.data.Response({
action: action,
success : this.getSuccess(root),
message: this.getMessage(root),
data: this.extractData(q.select(this.meta.record, root) || q.select(this.meta.root, root), false),
raw: doc
});
if (Ext.isEmpty(res.success)) {
throw new Ext.data.DataReader.Error('successProperty-response', this.meta.successProperty);
}
// Create actions from a response having status 200 must return pk
if (action === Ext.data.Api.actions.create) {
var def = Ext.isDefined(res.data);
if (def && Ext.isEmpty(res.data)) {
throw new Ext.data.JsonReader.Error('root-empty', this.meta.root);
}
else if (!def) {
throw new Ext.data.JsonReader.Error('root-undefined-response', this.meta.root);
}
}
return res;
},
getSuccess : function() {
return true;
},
* build response-data extractor functions.
* @private
* @ignore
*/
buildExtractors : function() {
if(this.ef){
return;
}
var s = this.meta,
Record = this.recordType,
f = Record.prototype.fields,
fi = f.items,
fl = f.length;
if(s.totalProperty) {
this.getTotal = this.createAccessor(s.totalProperty);
}
if(s.successProperty) {
this.getSuccess = this.createAccessor(s.successProperty);
}
if (s.messageProperty) {
this.getMessage = this.createAccessor(s.messageProperty);
}
this.getRoot = function(res) {
return (!Ext.isEmpty(res[this.meta.record])) ? res[this.meta.record] : res[this.meta.root];
};
if (s.idPath || s.idProperty) {
var g = this.createAccessor(s.idPath || s.idProperty);
this.getId = function(rec) {
var id = g(rec) || rec.id;
return (id === undefined || id === '') ? null : id;
};
} 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 : f.name;
ef.push(this.createAccessor(map));
}
this.ef = ef;
},
/**
* Creates a function to return some particular key of data from a response.
* @param {String} key
* @return {Function}
* @private
* @ignore
*/
createAccessor : function(){
var q = Ext.DomQuery;
return function(key) {
if (Ext.isFunction(key)) {
return key;
}
switch(key) {
case this.meta.totalProperty:
return function(root, def){
return q.selectNumber(key, root, def);
};
break;
case this.meta.successProperty:
return function(root, def) {
var sv = q.selectValue(key, root, true);
var success = sv !== false && sv !== 'false';
return success;
};
break;
default:
return function(root, def) {
return q.selectValue(key, root, def);
};
break;
}
};
}(),
* extracts values and type-casts a row of data from server, extracted by #extractData
* @param {Hash} data
* @param {Ext.data.Field[]} items
* @param {Number} len
* @private
* @ignore
*/
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;
}
});