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   1  /*
   2  YUI 3.17.2 (build 9c3c78e)
   3  Copyright 2014 Yahoo! Inc. All rights reserved.
   4  Licensed under the BSD License.
   5  http://yuilibrary.com/license/
   6  */
   7  
   8  YUI.add('dataschema-xml', function (Y, NAME) {
   9  
  10  /**
  11  Provides a DataSchema implementation which can be used to work with XML data.
  12  
  13  @module dataschema
  14  @submodule dataschema-xml
  15  **/
  16  
  17  /**
  18  Provides a DataSchema implementation which can be used to work with XML data.
  19  
  20  See the `apply` method for usage.
  21  
  22  @class DataSchema.XML
  23  @extends DataSchema.Base
  24  @static
  25  **/
  26  var Lang = Y.Lang,
  27  
  28      okNodeType = {
  29          1 : true,
  30          9 : true,
  31          11: true
  32      },
  33  
  34      SchemaXML;
  35  
  36  SchemaXML = {
  37  
  38      ////////////////////////////////////////////////////////////////////////////
  39      //
  40      // DataSchema.XML static methods
  41      //
  42      ////////////////////////////////////////////////////////////////////////////
  43      /**
  44      Applies a schema to an XML data tree, returning a normalized object with
  45      results in the `results` property. Additional information can be parsed out
  46      of the XML for inclusion in the `meta` property of the response object.  If
  47      an error is encountered during processing, an `error` property will be
  48      added.
  49  
  50      Field data in the nodes captured by the XPath in _schema.resultListLocator_
  51      is extracted with the field identifiers described in _schema.resultFields_.
  52      Field identifiers are objects with the following properties:
  53  
  54        * `key`    : <strong>(required)</strong> The desired property name to use
  55              store the retrieved value in the result object.  If `locator` is
  56              not specified, `key` is also used as the XPath locator (String)
  57        * `locator`: The XPath locator to the node or attribute within each
  58              result node found by _schema.resultListLocator_ containing the
  59              desired field data (String)
  60        * `parser` : A function or the name of a function on `Y.Parsers` used
  61              to convert the input value into a normalized type.  Parser
  62              functions are passed the value as input and are expected to
  63              return a value.
  64        * `schema` : Used to retrieve nested field data into an array for
  65              assignment as the result field value.  This object follows the same
  66              conventions as _schema_.
  67  
  68      If no value parsing or nested parsing is needed, you can use XPath locators
  69      (strings) instead of field identifiers (objects) -- see example below.
  70  
  71      `response.results` will contain an array of objects with key:value pairs.
  72      The keys are the field identifier `key`s, and the values are the data
  73      values extracted from the nodes or attributes found by the field `locator`
  74      (or `key` fallback).
  75  
  76      To extract additional information from the XML, include an array of
  77      XPath locators in _schema.metaFields_.  The collected values will be
  78      stored in `response.meta` with the XPath locator as keys.
  79  
  80      @example
  81          var schema = {
  82                  resultListLocator: '//produce/item',
  83                  resultFields: [
  84                      {
  85                          locator: 'name',
  86                          key: 'name'
  87                      },
  88                      {
  89                          locator: 'color',
  90                          key: 'color',
  91                          parser: function (val) { return val.toUpperCase(); }
  92                      }
  93                  ]
  94              };
  95  
  96          // Assumes data like
  97          // <inventory>
  98          //   <produce>
  99          //     <item><name>Banana</name><color>yellow</color></item>
 100          //     <item><name>Orange</name><color>orange</color></item>
 101          //     <item><name>Eggplant</name><color>purple</color></item>
 102          //   </produce>
 103          // </inventory>
 104  
 105          var response = Y.DataSchema.JSON.apply(schema, data);
 106  
 107          // response.results[0] is { name: "Banana", color: "YELLOW" }
 108  
 109      @method apply
 110      @param {Object} schema Schema to apply.  Supported configuration
 111          properties are:
 112        @param {String} [schema.resultListLocator] XPath locator for the
 113            XML nodes that contain the data to flatten into `response.results`
 114        @param {Array} [schema.resultFields] Field identifiers to
 115            locate/assign values in the response records. See above for
 116            details.
 117        @param {Array} [schema.metaFields] XPath locators to extract extra
 118            non-record related information from the XML data
 119      @param {XMLDocument} data XML data to parse
 120      @return {Object} An Object with properties `results` and `meta`
 121      @static
 122      **/
 123      apply: function(schema, data) {
 124          var xmldoc = data, // unnecessary variables
 125              data_out = { results: [], meta: {} };
 126  
 127          if (xmldoc && okNodeType[xmldoc.nodeType] && schema) {
 128              // Parse results data
 129              data_out = SchemaXML._parseResults(schema, xmldoc, data_out);
 130  
 131              // Parse meta data
 132              data_out = SchemaXML._parseMeta(schema.metaFields, xmldoc, data_out);
 133          } else {
 134              Y.log("XML data could not be schema-parsed: " + Y.dump(data) + " " + Y.dump(data), "error", "dataschema-xml");
 135              data_out.error = new Error("XML schema parse failure");
 136          }
 137  
 138          return data_out;
 139      },
 140  
 141      /**
 142       * Get an XPath-specified value for a given field from an XML node or document.
 143       *
 144       * @method _getLocationValue
 145       * @param field {String | Object} Field definition.
 146       * @param context {Object} XML node or document to search within.
 147       * @return {Object} Data value or null.
 148       * @static
 149       * @protected
 150       */
 151      _getLocationValue: function(field, context) {
 152          var locator = field.locator || field.key || field,
 153              xmldoc = context.ownerDocument || context,
 154              result, res, value = null;
 155  
 156          try {
 157              result = SchemaXML._getXPathResult(locator, context, xmldoc);
 158              while ((res = result.iterateNext())) {
 159                  value = res.textContent || res.value || res.text || res.innerHTML || res.innerText || null;
 160              }
 161  
 162              // FIXME: Why defer to a method that is mixed into this object?
 163              // DSchema.Base is mixed into DSchema.XML (et al), so
 164              // DSchema.XML.parse(...) will work.  This supports the use case
 165              // where DSchema.Base.parse is changed, and that change is then
 166              // seen by all DSchema.* implementations, but does not support the
 167              // case where redefining DSchema.XML.parse changes behavior. In
 168              // fact, DSchema.XML.parse is never even called.
 169              return Y.DataSchema.Base.parse.call(this, value, field);
 170          } catch (e) {
 171              Y.log('SchemaXML._getLocationValue failed: ' + e.message);
 172          }
 173  
 174          return null;
 175      },
 176  
 177      /**
 178       * Fetches the XPath-specified result for a given location in an XML node
 179       * or document.
 180       *
 181       * @method _getXPathResult
 182       * @param locator {String} The XPath location.
 183       * @param context {Object} XML node or document to search within.
 184       * @param xmldoc {Object} XML document to resolve namespace.
 185       * @return {Object} Data collection or null.
 186       * @static
 187       * @protected
 188       */
 189      _getXPathResult: function(locator, context, xmldoc) {
 190          // Standards mode
 191          if (! Lang.isUndefined(xmldoc.evaluate)) {
 192              return xmldoc.evaluate(locator, context, xmldoc.createNSResolver(context.ownerDocument ? context.ownerDocument.documentElement : context.documentElement), 0, null);
 193  
 194          }
 195          // IE mode
 196          else {
 197              var values=[], locatorArray = locator.split(/\b\/\b/), i=0, l=locatorArray.length, location, subloc, m, isNth;
 198  
 199              // XPath is supported
 200              try {
 201                  // this fixes the IE 5.5+ issue where childnode selectors begin at 0 instead of 1
 202                  try {
 203                     xmldoc.setProperty("SelectionLanguage", "XPath");
 204                  } catch (e) {}
 205  
 206                  values = context.selectNodes(locator);
 207              }
 208              // Fallback for DOM nodes and fragments
 209              catch (e) {
 210                  // Iterate over each locator piece
 211                  for (; i<l && context; i++) {
 212                      location = locatorArray[i];
 213  
 214                      // grab nth child []
 215                      if ((location.indexOf("[") > -1) && (location.indexOf("]") > -1)) {
 216                          subloc = location.slice(location.indexOf("[")+1, location.indexOf("]"));
 217                          //XPath is 1-based while DOM is 0-based
 218                          subloc--;
 219                          context = context.children[subloc];
 220                          isNth = true;
 221                      }
 222                      // grab attribute value @
 223                      else if (location.indexOf("@") > -1) {
 224                          subloc = location.substr(location.indexOf("@"));
 225                          context = subloc ? context.getAttribute(subloc.replace('@', '')) : context;
 226                      }
 227                      // grab that last instance of tagName
 228                      else if (-1 < location.indexOf("//")) {
 229                          subloc = context.getElementsByTagName(location.substr(2));
 230                          context = subloc.length ? subloc[subloc.length - 1] : null;
 231                      }
 232                      // find the last matching location in children
 233                      else if (l != i + 1) {
 234                          for (m=context.childNodes.length-1; 0 <= m; m-=1) {
 235                              if (location === context.childNodes[m].tagName) {
 236                                  context = context.childNodes[m];
 237                                  m = -1;
 238                              }
 239                          }
 240                      }
 241                  }
 242  
 243                  if (context) {
 244                      // attribute
 245                      if (Lang.isString(context)) {
 246                          values[0] = {value: context};
 247                      }
 248                      // nth child
 249                      else if (isNth) {
 250                          values[0] = {value: context.innerHTML};
 251                      }
 252                      // all children
 253                      else {
 254                          values = Y.Array(context.childNodes, 0, true);
 255                      }
 256                  }
 257              }
 258  
 259              // returning a mock-standard object for IE
 260              return {
 261                  index: 0,
 262  
 263                  iterateNext: function() {
 264                      if (this.index >= this.values.length) {return undefined;}
 265                      var result = this.values[this.index];
 266                      this.index += 1;
 267                      return result;
 268                  },
 269  
 270                  values: values
 271              };
 272          }
 273      },
 274  
 275      /**
 276       * Schema-parsed result field.
 277       *
 278       * @method _parseField
 279       * @param field {String | Object} Required. Field definition.
 280       * @param result {Object} Required. Schema parsed data object.
 281       * @param context {Object} Required. XML node or document to search within.
 282       * @static
 283       * @protected
 284       */
 285      _parseField: function(field, result, context) {
 286          var key = field.key || field,
 287              parsed;
 288  
 289          if (field.schema) {
 290              parsed = { results: [], meta: {} };
 291              parsed = SchemaXML._parseResults(field.schema, context, parsed);
 292  
 293              result[key] = parsed.results;
 294          } else {
 295              result[key] = SchemaXML._getLocationValue(field, context);
 296          }
 297      },
 298  
 299      /**
 300       * Parses results data according to schema
 301       *
 302       * @method _parseMeta
 303       * @param xmldoc_in {Object} XML document parse.
 304       * @param data_out {Object} In-progress schema-parsed data to update.
 305       * @return {Object} Schema-parsed data.
 306       * @static
 307       * @protected
 308       */
 309      _parseMeta: function(metaFields, xmldoc_in, data_out) {
 310          if(Lang.isObject(metaFields)) {
 311              var key,
 312                  xmldoc = xmldoc_in.ownerDocument || xmldoc_in;
 313  
 314              for(key in metaFields) {
 315                  if (metaFields.hasOwnProperty(key)) {
 316                      data_out.meta[key] = SchemaXML._getLocationValue(metaFields[key], xmldoc);
 317                  }
 318              }
 319          }
 320          return data_out;
 321      },
 322  
 323      /**
 324       * Schema-parsed result to add to results list.
 325       *
 326       * @method _parseResult
 327       * @param fields {Array} Required. A collection of field definition.
 328       * @param context {Object} Required. XML node or document to search within.
 329       * @return {Object} Schema-parsed data.
 330       * @static
 331       * @protected
 332       */
 333      _parseResult: function(fields, context) {
 334          var result = {}, j;
 335  
 336          // Find each field value
 337          for (j=fields.length-1; 0 <= j; j--) {
 338              SchemaXML._parseField(fields[j], result, context);
 339          }
 340  
 341          return result;
 342      },
 343  
 344      /**
 345       * Schema-parsed list of results from full data
 346       *
 347       * @method _parseResults
 348       * @param schema {Object} Schema to parse against.
 349       * @param context {Object} XML node or document to parse.
 350       * @param data_out {Object} In-progress schema-parsed data to update.
 351       * @return {Object} Schema-parsed data.
 352       * @static
 353       * @protected
 354       */
 355      _parseResults: function(schema, context, data_out) {
 356          if (schema.resultListLocator && Lang.isArray(schema.resultFields)) {
 357              var xmldoc = context.ownerDocument || context,
 358                  fields = schema.resultFields,
 359                  results = [],
 360                  node, nodeList, i=0;
 361  
 362              if (schema.resultListLocator.match(/^[:\-\w]+$/)) {
 363                  nodeList = context.getElementsByTagName(schema.resultListLocator);
 364  
 365                  // loop through each result node
 366                  for (i = nodeList.length - 1; i >= 0; --i) {
 367                      results[i] = SchemaXML._parseResult(fields, nodeList[i]);
 368                  }
 369              } else {
 370                  nodeList = SchemaXML._getXPathResult(schema.resultListLocator, context, xmldoc);
 371  
 372                  // loop through the nodelist
 373                  while ((node = nodeList.iterateNext())) {
 374                      results[i] = SchemaXML._parseResult(fields, node);
 375                      i += 1;
 376                  }
 377              }
 378  
 379              if (results.length) {
 380                  data_out.results = results;
 381              } else {
 382                  data_out.error = new Error("XML schema result nodes retrieval failure");
 383              }
 384          }
 385          return data_out;
 386      }
 387  };
 388  
 389  Y.DataSchema.XML = Y.mix(SchemaXML, Y.DataSchema.Base);
 390  
 391  
 392  }, '3.17.2', {"requires": ["dataschema-base"]});