/**
* @author Ed Spencer
* @class Ext.data.reader.Xml
* @extends Ext.data.reader.Reader
*
* <p>The XML Reader is used by a Proxy to read a server response that is sent back in XML format. This usually
* happens as a result of loading a Store - for example we might create something like this:</p>
*
<pre><code>
Ext.define('User', {
extend: 'Ext.data.Model',
fields: ['id', 'name', 'email']
});
var store = new Ext.data.Store({
model: 'User',
proxy: {
type: 'ajax',
url : 'users.xml',
reader: {
type: 'xml',
record: 'user'
}
}
});
</code></pre>
*
* <p>The example above creates a 'User' model. Models are explained in the {@link Ext.data.Model Model} docs if you're
* not already familiar with them.</p>
*
* <p>We created the simplest type of XML Reader possible by simply telling our {@link Ext.data.Store Store}'s
* {@link Ext.data.proxy.Proxy Proxy} that we want a XML Reader. The Store automatically passes the configured model to the
* Store, so it is as if we passed this instead:
*
<pre><code>
reader: {
type : 'xml',
model: 'User',
record: 'user'
}
</code></pre>
*
* <p>The reader we set up is ready to read data from our server - at the moment it will accept a response like this:</p>
*
<pre><code>
<?xml version="1.0" encoding="UTF-8"?>
<user>
<id>1</id>
<name>Ed Spencer</name>
<email>ed@sencha.com</email>
</user>
<user>
<id>2</id>
<name>Abe Elias</name>
<email>abe@sencha.com</email>
</user>
</code></pre>
*
* <p>The XML Reader uses the configured {@link #record} option to pull out the data for each record - in this case we
* set record to 'user', so each <user> above will be converted into a User model.</p>
*
* <p><u>Reading other XML formats</u></p>
*
* <p>If you already have your XML format defined and it doesn't look quite like what we have above, you can usually
* pass XmlReader a couple of configuration options to make it parse your format. For example, we can use the
* {@link #root} configuration to parse data that comes back like this:</p>
*
<pre><code>
<?xml version="1.0" encoding="UTF-8"?>
<users>
<user>
<id>1</id>
<name>Ed Spencer</name>
<email>ed@sencha.com</email>
</user>
<user>
<id>2</id>
<name>Abe Elias</name>
<email>abe@sencha.com</email>
</user>
</users>
</code></pre>
*
* <p>To parse this we just pass in a {@link #root} configuration that matches the 'users' above:</p>
*
<pre><code>
reader: {
type : 'xml',
root : 'users',
record: 'user'
}
</code></pre>
*
* <p>Note that XmlReader doesn't care whether your {@link #root} and {@link #record} elements are nested deep inside
* a larger structure, so a response like this will still work:
*
<pre><code>
<?xml version="1.0" encoding="UTF-8"?>
<deeply>
<nested>
<xml>
<users>
<user>
<id>1</id>
<name>Ed Spencer</name>
<email>ed@sencha.com</email>
</user>
<user>
<id>2</id>
<name>Abe Elias</name>
<email>abe@sencha.com</email>
</user>
</users>
</xml>
</nested>
</deeply>
</code></pre>
*
* <p><u>Response metadata</u></p>
*
* <p>The server can return additional data in its response, such as the {@link #totalProperty total number of records}
* and the {@link #successProperty success status of the response}. These are typically included in the XML response
* like this:</p>
*
<pre><code>
<?xml version="1.0" encoding="UTF-8"?>
<total>100</total>
<success>true</success>
<users>
<user>
<id>1</id>
<name>Ed Spencer</name>
<email>ed@sencha.com</email>
</user>
<user>
<id>2</id>
<name>Abe Elias</name>
<email>abe@sencha.com</email>
</user>
</users>
</code></pre>
*
* <p>If these properties are present in the XML response they can be parsed out by the XmlReader and used by the
* Store that loaded it. We can set up the names of these properties by specifying a final pair of configuration
* options:</p>
*
<pre><code>
reader: {
type: 'xml',
root: 'users',
totalProperty : 'total',
successProperty: 'success'
}
</code></pre>
*
* <p>These final options are not necessary to make the Reader work, but can be useful when the server needs to report
* an error or if it needs to indicate that there is a lot of data available of which only a subset is currently being
* returned.</p>
*
* <p><u>Response format</u></p>
*
* <p><b>Note:</b> 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". This is very important - the XmlReader will not
* work correctly otherwise.</p>
*/
Ext.define('Ext.data.reader.Xml', {
extend: 'Ext.data.reader.Reader',
alternateClassName: 'Ext.data.XmlReader',
alias : 'reader.xml',
/**
* @cfg {String} record The DomQuery path to the repeated element which contains record information.
*/
/**
* @private
* Creates a function to return some particular key of data from a response. The totalProperty and
* successProperty are treated as special cases for type casting, everything else is just a simple selector.
* @param {String} key
* @return {Function}
*/
createAccessor: function(expr) {
var me = this;
if (Ext.isEmpty(expr)) {
return Ext.emptyFn;
}
if (Ext.isFunction(expr)) {
return expr;
}
return function(root) {
return me.getNodeValue(Ext.DomQuery.selectNode(expr, root));
};
},
getNodeValue: function(node) {
if (node && node.firstChild) {
return node.firstChild.nodeValue;
}
return undefined;
},
//inherit docs
getResponseData: function(response) {
var xml = response.responseXML;
//<debug>
if (!xml) {
Ext.Error.raise({
response: response,
msg: 'XML data not found in the response'
});
}
//</debug>
return xml;
},
/**
* Normalizes the data object
* @param {Object} data The raw data object
* @return {Object} Returns the documentElement property of the data object if present, or the same object if not
*/
getData: function(data) {
return data.documentElement || data;
},
/**
* @private
* Given an XML object, returns the Element that represents the root as configured by the Reader's meta data
* @param {Object} data The XML data object
* @return {Element} The root node element
*/
getRoot: function(data) {
var nodeName = data.nodeName,
root = this.root;
if (!root || (nodeName && nodeName == root)) {
return data;
} else if (Ext.DomQuery.isXml(data)) {
// This fix ensures we have XML data
// Related to TreeStore calling getRoot with the root node, which isn't XML
// Probably should be resolved in TreeStore at some point
return Ext.DomQuery.selectNode(root, data);
}
},
* @private
* We're just preparing the data for the superclass by pulling out the record nodes we want
* @param {Element} root The XML root node
* @return {Array} The records
*/
extractData: function(root) {
var recordName = this.record;
//<debug>
if (!recordName) {
Ext.Error.raise('Record is a required parameter');
}
//</debug>
if (recordName != root.nodeName) {
root = Ext.DomQuery.select(recordName, root);
} else {
root = [root];
}
return this.callParent([root]);
},
/**
* @private
* See Ext.data.reader.Reader's getAssociatedDataRoot docs
* @param {Mixed} data The raw data object
* @param {String} associationName The name of the association to get data for (uses associationKey if present)
* @return {Mixed} The root
*/
getAssociatedDataRoot: function(data, associationName) {
return Ext.DomQuery.select(associationName, data)[0];
},
/**
* Parses an XML document and returns a ResultSet containing the model instances
* @param {Object} doc Parsed XML document
* @return {Ext.data.ResultSet} The parsed result set
*/
readRecords: function(doc) {
//it's possible that we get passed an array here by associations. Make sure we strip that out (see Ext.data.reader.Reader#readAssociated)
if (Ext.isArray(doc)) {
doc = doc[0];
}
/**
* DEPRECATED - will be removed in Ext JS 5.0. This is just a copy of this.rawData - use that instead
* @property xmlData
* @type Object
*/
this.xmlData = doc;
return this.callParent([doc]);
}
});