dataschema-xml.js revision 3a38d5b7ad9ebee258ce6cb2ebe712f058ea27c5
/**
* The DataSchema utility provides a common configurable interface for widgets to
* apply a given schema to a variety of data.
*
* @module dataschema
*/
var LANG = Y.Lang,
/**
* XML subclass for the YUI DataSchema utility.
* @class DataSchema.XML
* @extends DataSchema.Base
* @static
*/
SchemaXML = {
/////////////////////////////////////////////////////////////////////////////
//
// DataSchema.XML static methods
//
/////////////////////////////////////////////////////////////////////////////
/**
* Returns string name.
*
* @method toString
* @return {String} String representation for this object.
*/
toString: function() {
return "DataSchema.XML";
},
/**
* Applies a given schema to given XML data.
*
* @method apply
* @param schema {Object} Schema to apply.
* @param data {XMLDoc} XML document.
* @return {Object} Schema-parsed data.
* @static
*/
apply: function(schema, data) {
var xmldoc = data,
data_out = {results:[],meta:{}};
if(LANG.isObject(xmldoc) && schema) {
// Parse results data
data_out = SchemaXML._parseResults(schema, xmldoc, data_out);
// Parse meta data
data_out = SchemaXML._parseMeta(schema.metaFields, xmldoc, data_out);
}
else {
Y.log("XML data could not be schema-parsed: " + Y.dump(data) + " " + Y.dump(data), "error", SchemaXML.toString());
data_out.error = new Error(this.toString() + " Schema parse failure");
}
return data_out;
},
/**
* Get an XPath-specified value for a given field from an XML node or document.
*
* @method _getLocationValue
* @param field {String | Object} Field definition.
* @param context {Object} XML node or document to search within.
* @return {Object} Data value or null.
* @static
* @protected
*/
_getLocationValue: function(field, context) {
var locator = field.locator || field.key || field,
xmldoc = context.ownerDocument || context,
result, res, value = null;
try {
// Standards mode
if(!LANG.isUndefined(xmldoc.evaluate)) {
result = xmldoc.evaluate(locator, context, xmldoc.createNSResolver(!context.ownerDocument ? context.documentElement : context.ownerDocument.documentElement), 0, null);
while(res = result.iterateNext()) {
value = res.textContent;
}
}
// IE mode
else {
xmldoc.setProperty("SelectionLanguage", "XPath");
result = context.selectNodes(locator)[0];
value = result.value || result.text || null;
}
return Y.DataSchema.Base.parse(value, field);
}
catch(e) {
}
},
/**
* Parses results data according to schema
*
* @method _parseMeta
* @param xmldoc_in {Object} XML document parse.
* @param data_out {Object} In-progress schema-parsed data to update.
* @return {Object} Schema-parsed data.
* @static
* @protected
*/
_parseMeta: function(metaFields, xmldoc_in, data_out) {
if(LANG.isObject(metaFields)) {
var key,
xmldoc = xmldoc_in.ownerDocument || xmldoc_in;
for(key in metaFields) {
if (metaFields.hasOwnProperty(key)) {
data_out.meta[key] = SchemaXML._getLocationValue(metaFields[key], xmldoc);
}
}
}
return data_out;
},
/**
* Schema-parsed list of results from full data
*
* @method _parseResults
* @param schema {Object} Schema to parse against.
* @param xmldoc_in {Object} XML document parse.
* @param data_out {Object} In-progress schema-parsed data to update.
* @return {Object} Schema-parsed data.
* @static
* @protected
*/
_parseResults: function(schema, xmldoc_in, data_out) {
if(schema.resultsLocator && LANG.isArray(schema.resultsFields)) {
var nodeList = xmldoc_in.getElementsByTagName(schema.resultsLocator),
fields = schema.resultsFields,
results = [],
node, field, result, i, j;
if(nodeList.length) {
// Loop through each result node
for(i=nodeList.length-1; i>= 0; i--) {
result = {};
node = nodeList[i];
// Find each field value
for(j=fields.length-1; j>= 0; j--) {
field = fields[j];
result[field.key || field] = SchemaXML._getLocationValue(field, node);
}
results[i] = result;
}
data_out.results = results;
}
else {
data_out.error = new Error(this.toString() + " Result nodes retrieval failure");
}
}
return data_out;
}
};
Y.DataSchema.XML = Y.mix(SchemaXML, Y.DataSchema.Base);