1 YUI.add('dataschema-xml', function (Y, NAME) {

     2 

     3 /**

     4 Provides a DataSchema implementation which can be used to work with XML data.

     5 

     6 @module dataschema

     7 @submodule dataschema-xml

     8 **/

     9 

    10 /**

    11 Provides a DataSchema implementation which can be used to work with XML data.

    12 

    13 See the `apply` method for usage.

    14 

    15 @class DataSchema.XML

    16 @extends DataSchema.Base

    17 @static

    18 **/

    19 var Lang = Y.Lang,

    20 

    21     okNodeType = {

    22         1 : true,

    23         9 : true,

    24         11: true

    25     },

    26 

    27     SchemaXML;

    28 

    29 SchemaXML = {

    30 

    31     ////////////////////////////////////////////////////////////////////////////

    32     //

    33     // DataSchema.XML static methods

    34     //

    35     ////////////////////////////////////////////////////////////////////////////

    36     /**

    37     Applies a schema to an XML data tree, returning a normalized object with

    38     results in the `results` property. Additional information can be parsed out

    39     of the XML for inclusion in the `meta` property of the response object.  If

    40     an error is encountered during processing, an `error` property will be

    41     added.

    42 

    43     Field data in the nodes captured by the XPath in _schema.resultListLocator_

    44     is extracted with the field identifiers described in _schema.resultFields_.

    45     Field identifiers are objects with the following properties:

    46 

    47       * `key`    : <strong>(required)</strong> The desired property name to use

    48             store the retrieved value in the result object.  If `locator` is

    49             not specified, `key` is also used as the XPath locator (String)

    50       * `locator`: The XPath locator to the node or attribute within each

    51             result node found by _schema.resultListLocator_ containing the

    52             desired field data (String)

    53       * `parser` : A function or the name of a function on `Y.Parsers` used

    54             to convert the input value into a normalized type.  Parser

    55             functions are passed the value as input and are expected to

    56             return a value.

    57       * `schema` : Used to retrieve nested field data into an array for

    58             assignment as the result field value.  This object follows the same

    59             conventions as _schema_.

    60 

    61     If no value parsing or nested parsing is needed, you can use XPath locators

    62     (strings) instead of field identifiers (objects) -- see example below.

    63 

    64     `response.results` will contain an array of objects with key:value pairs.

    65     The keys are the field identifier `key`s, and the values are the data

    66     values extracted from the nodes or attributes found by the field `locator`

    67     (or `key` fallback).

    68 

    69     To extract additional information from the XML, include an array of

    70     XPath locators in _schema.metaFields_.  The collected values will be

    71     stored in `response.meta` with the XPath locator as keys.

    72 

    73     @example

    74         var schema = {

    75                 resultListLocator: '//produce/item',

    76                 resultFields: [

    77                     {

    78                         locator: 'name',

    79                         key: 'name'

    80                     },

    81                     {

    82                         locator: 'color',

    83                         key: 'color',

    84                         parser: function (val) { return val.toUpperCase(); }

    85                     }

    86                 ]

    87             };

    88 

    89         // Assumes data like

    90         // <inventory>

    91         //   <produce>

    92         //     <item><name>Banana</name><color>yellow</color></item>

    93         //     <item><name>Orange</name><color>orange</color></item>

    94         //     <item><name>Eggplant</name><color>purple</color></item>

    95         //   </produce>

    96         // </inventory>

    97 

    98         var response = Y.DataSchema.JSON.apply(schema, data);

    99 

   100         // response.results[0] is { name: "Banana", color: "YELLOW" }

   101 

   102     @method apply

   103     @param {Object} schema Schema to apply.  Supported configuration

   104         properties are:

   105       @param {String} [schema.resultListLocator] XPath locator for the

   106           XML nodes that contain the data to flatten into `response.results`

   107       @param {Array} [schema.resultFields] Field identifiers to

   108           locate/assign values in the response records. See above for

   109           details.

   110       @param {Array} [schema.metaFields] XPath locators to extract extra

   111           non-record related information from the XML data

   112     @param {XMLDocument} data XML data to parse

   113     @return {Object} An Object with properties `results` and `meta`

   114     @static

   115     **/

   116     apply: function(schema, data) {

   117         var xmldoc = data, // unnecessary variables

   118             data_out = { results: [], meta: {} };

   119 

   120         if (xmldoc && okNodeType[xmldoc.nodeType] && schema) {

   121             // Parse results data

   122             data_out = SchemaXML._parseResults(schema, xmldoc, data_out);

   123 

   124             // Parse meta data

   125             data_out = SchemaXML._parseMeta(schema.metaFields, xmldoc, data_out);

   126         } else {

   127             data_out.error = new Error("XML schema parse failure");

   128         }

   129 

   130         return data_out;

   131     },

   132 

   133     /**

   134      * Get an XPath-specified value for a given field from an XML node or document.

   135      *

   136      * @method _getLocationValue

   137      * @param field {String | Object} Field definition.

   138      * @param context {Object} XML node or document to search within.

   139      * @return {Object} Data value or null.

   140      * @static

   141      * @protected

   142      */

   143     _getLocationValue: function(field, context) {

   144         var locator = field.locator || field.key || field,

   145             xmldoc = context.ownerDocument || context,

   146             result, res, value = null;

   147 

   148         try {

   149             result = SchemaXML._getXPathResult(locator, context, xmldoc);

   150             while ((res = result.iterateNext())) {

   151                 value = res.textContent || res.value || res.text || res.innerHTML || res.innerText || null;

   152             }

   153 

   154             // FIXME: Why defer to a method that is mixed into this object?

   155             // DSchema.Base is mixed into DSchema.XML (et al), so

   156             // DSchema.XML.parse(...) will work.  This supports the use case

   157             // where DSchema.Base.parse is changed, and that change is then

   158             // seen by all DSchema.* implementations, but does not support the

   159             // case where redefining DSchema.XML.parse changes behavior. In

   160             // fact, DSchema.XML.parse is never even called.

   161             return Y.DataSchema.Base.parse.call(this, value, field);

   162         } catch (e) {

   163         }

   164 

   165         return null;

   166     },

   167 

   168     /**

   169      * Fetches the XPath-specified result for a given location in an XML node

   170      * or document.

   171      *

   172      * @method _getXPathResult

   173      * @param locator {String} The XPath location.

   174      * @param context {Object} XML node or document to search within.

   175      * @param xmldoc {Object} XML document to resolve namespace.

   176      * @return {Object} Data collection or null.

   177      * @static

   178      * @protected

   179      */

   180     _getXPathResult: function(locator, context, xmldoc) {

   181         // Standards mode

   182         if (! Lang.isUndefined(xmldoc.evaluate)) {

   183             return xmldoc.evaluate(locator, context, xmldoc.createNSResolver(context.ownerDocument ? context.ownerDocument.documentElement : context.documentElement), 0, null);

   184 

   185         }

   186         // IE mode

   187         else {

   188             var values=[], locatorArray = locator.split(/\b\/\b/), i=0, l=locatorArray.length, location, subloc, m, isNth;

   189 

   190             // XPath is supported

   191             try {

   192                 // this fixes the IE 5.5+ issue where childnode selectors begin at 0 instead of 1

   193                 try {

   194                    xmldoc.setProperty("SelectionLanguage", "XPath");

   195                 } catch (e) {}

   196 

   197                 values = context.selectNodes(locator);

   198             }

   199             // Fallback for DOM nodes and fragments

   200             catch (e) {

   201                 // Iterate over each locator piece

   202                 for (; i<l && context; i++) {

   203                     location = locatorArray[i];

   204 

   205                     // grab nth child []

   206                     if ((location.indexOf("[") > -1) && (location.indexOf("]") > -1)) {

   207                         subloc = location.slice(location.indexOf("[")+1, location.indexOf("]"));

   208                         //XPath is 1-based while DOM is 0-based

   209                         subloc--;

   210                         context = context.children[subloc];

   211                         isNth = true;

   212                     }

   213                     // grab attribute value @

   214                     else if (location.indexOf("@") > -1) {

   215                         subloc = location.substr(location.indexOf("@"));

   216                         context = subloc ? context.getAttribute(subloc.replace('@', '')) : context;

   217                     }

   218                     // grab that last instance of tagName

   219                     else if (-1 < location.indexOf("//")) {

   220                         subloc = context.getElementsByTagName(location.substr(2));

   221                         context = subloc.length ? subloc[subloc.length - 1] : null;

   222                     }

   223                     // find the last matching location in children

   224                     else if (l != i + 1) {

   225                         for (m=context.childNodes.length-1; 0 <= m; m-=1) {

   226                             if (location === context.childNodes[m].tagName) {

   227                                 context = context.childNodes[m];

   228                                 m = -1;

   229                             }

   230                         }

   231                     }

   232                 }

   233 

   234                 if (context) {

   235                     // attribute

   236                     if (Lang.isString(context)) {

   237                         values[0] = {value: context};

   238                     }

   239                     // nth child

   240                     else if (isNth) {

   241                         values[0] = {value: context.innerHTML};

   242                     }

   243                     // all children

   244                     else {

   245                         values = Y.Array(context.childNodes, 0, true);

   246                     }

   247                 }

   248             }

   249 

   250             // returning a mock-standard object for IE

   251             return {

   252                 index: 0,

   253 

   254                 iterateNext: function() {

   255                     if (this.index >= this.values.length) {return undefined;}

   256                     var result = this.values[this.index];

   257                     this.index += 1;

   258                     return result;

   259                 },

   260 

   261                 values: values

   262             };

   263         }

   264     },

   265 

   266     /**

   267      * Schema-parsed result field.

   268      *

   269      * @method _parseField

   270      * @param field {String | Object} Required. Field definition.

   271      * @param result {Object} Required. Schema parsed data object.

   272      * @param context {Object} Required. XML node or document to search within.

   273      * @static

   274      * @protected

   275      */

   276     _parseField: function(field, result, context) {

   277         var key = field.key || field,

   278             parsed;

   279 

   280         if (field.schema) {

   281             parsed = { results: [], meta: {} };

   282             parsed = SchemaXML._parseResults(field.schema, context, parsed);

   283 

   284             result[key] = parsed.results;

   285         } else {

   286             result[key] = SchemaXML._getLocationValue(field, context);

   287         }

   288     },

   289 

   290     /**

   291      * Parses results data according to schema

   292      *

   293      * @method _parseMeta

   294      * @param xmldoc_in {Object} XML document parse.

   295      * @param data_out {Object} In-progress schema-parsed data to update.

   296      * @return {Object} Schema-parsed data.

   297      * @static

   298      * @protected

   299      */

   300     _parseMeta: function(metaFields, xmldoc_in, data_out) {

   301         if(Lang.isObject(metaFields)) {

   302             var key,

   303                 xmldoc = xmldoc_in.ownerDocument || xmldoc_in;

   304 

   305             for(key in metaFields) {

   306                 if (metaFields.hasOwnProperty(key)) {

   307                     data_out.meta[key] = SchemaXML._getLocationValue(metaFields[key], xmldoc);

   308                 }

   309             }

   310         }

   311         return data_out;

   312     },

   313 

   314     /**

   315      * Schema-parsed result to add to results list.

   316      *

   317      * @method _parseResult

   318      * @param fields {Array} Required. A collection of field definition.

   319      * @param context {Object} Required. XML node or document to search within.

   320      * @return {Object} Schema-parsed data.

   321      * @static

   322      * @protected

   323      */

   324     _parseResult: function(fields, context) {

   325         var result = {}, j;

   326 

   327         // Find each field value

   328         for (j=fields.length-1; 0 <= j; j--) {

   329             SchemaXML._parseField(fields[j], result, context);

   330         }

   331 

   332         return result;

   333     },

   334 

   335     /**

   336      * Schema-parsed list of results from full data

   337      *

   338      * @method _parseResults

   339      * @param schema {Object} Schema to parse against.

   340      * @param context {Object} XML node or document to parse.

   341      * @param data_out {Object} In-progress schema-parsed data to update.

   342      * @return {Object} Schema-parsed data.

   343      * @static

   344      * @protected

   345      */

   346     _parseResults: function(schema, context, data_out) {

   347         if (schema.resultListLocator && Lang.isArray(schema.resultFields)) {

   348             var xmldoc = context.ownerDocument || context,

   349                 fields = schema.resultFields,

   350                 results = [],

   351                 node, nodeList, i=0;

   352 

   353             if (schema.resultListLocator.match(/^[:\-\w]+$/)) {

   354                 nodeList = context.getElementsByTagName(schema.resultListLocator);

   355 

   356                 // loop through each result node

   357                 for (i = nodeList.length - 1; i >= 0; --i) {

   358                     results[i] = SchemaXML._parseResult(fields, nodeList[i]);

   359                 }

   360             } else {

   361                 nodeList = SchemaXML._getXPathResult(schema.resultListLocator, context, xmldoc);

   362 

   363                 // loop through the nodelist

   364                 while ((node = nodeList.iterateNext())) {

   365                     results[i] = SchemaXML._parseResult(fields, node);

   366                     i += 1;

   367                 }

   368             }

   369 

   370             if (results.length) {

   371                 data_out.results = results;

   372             } else {

   373                 data_out.error = new Error("XML schema result nodes retrieval failure");

   374             }

   375         }

   376         return data_out;

   377     }

   378 };

   379 

   380 Y.DataSchema.XML = Y.mix(SchemaXML, Y.DataSchema.Base);

   381 

   382 

   383 }, '@VERSION@', {"requires": ["dataschema-base"]});