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   1  // The MIT License
   2  //
   3  // Copyright (c) 2009 Chris Wanstrath (Ruby)
   4  // Copyright (c) 2010-2014 Jan Lehnardt (JavaScript)
   5  // Copyright (c) 2010-2015 The mustache.js community
   6  //
   7  // Permission is hereby granted, free of charge, to any person obtaining
   8  // a copy of this software and associated documentation files (the
   9  // "Software"), to deal in the Software without restriction, including
  10  // without limitation the rights to use, copy, modify, merge, publish,
  11  // distribute, sublicense, and/or sell copies of the Software, and to
  12  // permit persons to whom the Software is furnished to do so, subject to
  13  // the following conditions:
  14  //
  15  // The above copyright notice and this permission notice shall be
  16  // included in all copies or substantial portions of the Software.
  17  //
  18  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  21  // IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  22  // CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  // SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  //
  26  
  27  // Description of import into Moodle:
  28  // Checkout from https://github.com/moodle/custom-mustache.js Branch: LAMBDA_ARGS
  29  // Rebase onto latest release tag from https://github.com/janl/mustache.js
  30  // Copy mustache.js into lib/amd/src/ in Moodle folder.
  31  // Add the license as a comment to the file and these instructions.
  32  // Add jshint tags so this file is not linted.
  33  // Remove the "global define:" comment (hint for linter)
  34  // Make sure that you have not removed the custom code for '$' and '<'.
  35  
  36  /*!
  37   * mustache.js - Logic-less {{mustache}} templates with JavaScript
  38   * http://github.com/janl/mustache.js
  39   */
  40  
  41  /* jshint ignore:start */
  42  
  43  (function defineMustache (global, factory) {
  44    if (typeof exports === 'object' && exports && typeof exports.nodeName !== 'string') {
  45      factory(exports); // CommonJS
  46    } else if (typeof define === 'function' && define.amd) {
  47      define(['exports'], factory); // AMD
  48    } else {
  49      global.Mustache = {};
  50      factory(global.Mustache); // script, wsh, asp
  51    }
  52  }(this, function mustacheFactory (mustache) {
  53  
  54    var objectToString = Object.prototype.toString;
  55    var isArray = Array.isArray || function isArrayPolyfill (object) {
  56      return objectToString.call(object) === '[object Array]';
  57    };
  58  
  59    function isFunction (object) {
  60      return typeof object === 'function';
  61    }
  62  
  63    /**
  64     * More correct typeof string handling array
  65     * which normally returns typeof 'object'
  66     */
  67    function typeStr (obj) {
  68      return isArray(obj) ? 'array' : typeof obj;
  69    }
  70  
  71    function escapeRegExp (string) {
  72      return string.replace(/[\-\[\]{}()*+?.,\\\^$|#\s]/g, '\\$&');
  73    }
  74  
  75    /**
  76     * Null safe way of checking whether or not an object,
  77     * including its prototype, has a given property
  78     */
  79    function hasProperty (obj, propName) {
  80      return obj != null && typeof obj === 'object' && (propName in obj);
  81    }
  82  
  83    /**
  84     * Safe way of detecting whether or not the given thing is a primitive and
  85     * whether it has the given property
  86     */
  87    function primitiveHasOwnProperty (primitive, propName) {
  88      return (
  89        primitive != null
  90        && typeof primitive !== 'object'
  91        && primitive.hasOwnProperty
  92        && primitive.hasOwnProperty(propName)
  93      );
  94    }
  95  
  96    // Workaround for https://issues.apache.org/jira/browse/COUCHDB-577
  97    // See https://github.com/janl/mustache.js/issues/189
  98    var regExpTest = RegExp.prototype.test;
  99    function testRegExp (re, string) {
 100      return regExpTest.call(re, string);
 101    }
 102  
 103    var nonSpaceRe = /\S/;
 104    function isWhitespace (string) {
 105      return !testRegExp(nonSpaceRe, string);
 106    }
 107  
 108    var entityMap = {
 109      '&': '&amp;',
 110      '<': '&lt;',
 111      '>': '&gt;',
 112      '"': '&quot;',
 113      "'": '&#39;',
 114      '/': '&#x2F;',
 115      '`': '&#x60;',
 116      '=': '&#x3D;'
 117    };
 118  
 119    function escapeHtml (string) {
 120      return String(string).replace(/[&<>"'`=\/]/g, function fromEntityMap (s) {
 121        return entityMap[s];
 122      });
 123    }
 124  
 125    var whiteRe = /\s*/;
 126    var spaceRe = /\s+/;
 127    var equalsRe = /\s*=/;
 128    var curlyRe = /\s*\}/;
 129    var tagRe = /#|\^|\/|>|\{|&|=|!|\$|</;
 130  
 131    /**
 132     * Breaks up the given `template` string into a tree of tokens. If the `tags`
 133     * argument is given here it must be an array with two string values: the
 134     * opening and closing tags used in the template (e.g. [ "<%", "%>" ]). Of
 135     * course, the default is to use mustaches (i.e. mustache.tags).
 136     *
 137     * A token is an array with at least 4 elements. The first element is the
 138     * mustache symbol that was used inside the tag, e.g. "#" or "&". If the tag
 139     * did not contain a symbol (i.e. {{myValue}}) this element is "name". For
 140     * all text that appears outside a symbol this element is "text".
 141     *
 142     * The second element of a token is its "value". For mustache tags this is
 143     * whatever else was inside the tag besides the opening symbol. For text tokens
 144     * this is the text itself.
 145     *
 146     * The third and fourth elements of the token are the start and end indices,
 147     * respectively, of the token in the original template.
 148     *
 149     * Tokens that are the root node of a subtree contain two more elements: 1) an
 150     * array of tokens in the subtree and 2) the index in the original template at
 151     * which the closing tag for that section begins.
 152     *
 153     * Tokens for partials also contain two more elements: 1) a string value of
 154     * indendation prior to that tag and 2) the index of that tag on that line -
 155     * eg a value of 2 indicates the partial is the third tag on this line.
 156     */
 157    function parseTemplate (template, tags) {
 158      if (!template)
 159        return [];
 160      var lineHasNonSpace = false;
 161      var sections = [];     // Stack to hold section tokens
 162      var tokens = [];       // Buffer to hold the tokens
 163      var spaces = [];       // Indices of whitespace tokens on the current line
 164      var hasTag = false;    // Is there a {{tag}} on the current line?
 165      var nonSpace = false;  // Is there a non-space char on the current line?
 166      var indentation = '';  // Tracks indentation for tags that use it
 167      var tagIndex = 0;      // Stores a count of number of tags encountered on a line
 168  
 169      // Strips all whitespace tokens array for the current line
 170      // if there was a {{#tag}} on it and otherwise only space.
 171      function stripSpace () {
 172        if (hasTag && !nonSpace) {
 173          while (spaces.length)
 174            delete tokens[spaces.pop()];
 175        } else {
 176          spaces = [];
 177        }
 178  
 179        hasTag = false;
 180        nonSpace = false;
 181      }
 182  
 183      var openingTagRe, closingTagRe, closingCurlyRe;
 184      function compileTags (tagsToCompile) {
 185        if (typeof tagsToCompile === 'string')
 186          tagsToCompile = tagsToCompile.split(spaceRe, 2);
 187  
 188        if (!isArray(tagsToCompile) || tagsToCompile.length !== 2)
 189          throw new Error('Invalid tags: ' + tagsToCompile);
 190  
 191        openingTagRe = new RegExp(escapeRegExp(tagsToCompile[0]) + '\\s*');
 192        closingTagRe = new RegExp('\\s*' + escapeRegExp(tagsToCompile[1]));
 193        closingCurlyRe = new RegExp('\\s*' + escapeRegExp('}' + tagsToCompile[1]));
 194      }
 195  
 196      compileTags(tags || mustache.tags);
 197  
 198      var scanner = new Scanner(template);
 199  
 200      var start, type, value, chr, token, openSection;
 201      while (!scanner.eos()) {
 202        start = scanner.pos;
 203  
 204        // Match any text between tags.
 205        value = scanner.scanUntil(openingTagRe);
 206  
 207        if (value) {
 208          for (var i = 0, valueLength = value.length; i < valueLength; ++i) {
 209            chr = value.charAt(i);
 210  
 211            if (isWhitespace(chr)) {
 212              spaces.push(tokens.length);
 213              indentation += chr;
 214            } else {
 215              nonSpace = true;
 216              lineHasNonSpace = true;
 217              indentation += ' ';
 218            }
 219  
 220            tokens.push([ 'text', chr, start, start + 1 ]);
 221            start += 1;
 222  
 223            // Check for whitespace on the current line.
 224            if (chr === '\n') {
 225              stripSpace();
 226              indentation = '';
 227              tagIndex = 0;
 228              lineHasNonSpace = false;
 229            }
 230          }
 231        }
 232  
 233        // Match the opening tag.
 234        if (!scanner.scan(openingTagRe))
 235          break;
 236  
 237        hasTag = true;
 238  
 239        // Get the tag type.
 240        type = scanner.scan(tagRe) || 'name';
 241        scanner.scan(whiteRe);
 242  
 243        // Get the tag value.
 244        if (type === '=') {
 245          value = scanner.scanUntil(equalsRe);
 246          scanner.scan(equalsRe);
 247          scanner.scanUntil(closingTagRe);
 248        } else if (type === '{') {
 249          value = scanner.scanUntil(closingCurlyRe);
 250          scanner.scan(curlyRe);
 251          scanner.scanUntil(closingTagRe);
 252          type = '&';
 253        } else {
 254          value = scanner.scanUntil(closingTagRe);
 255        }
 256  
 257        // Match the closing tag.
 258        if (!scanner.scan(closingTagRe))
 259          throw new Error('Unclosed tag at ' + scanner.pos);
 260  
 261        if (type == '>') {
 262          token = [ type, value, start, scanner.pos, indentation, tagIndex, lineHasNonSpace ];
 263        } else {
 264          token = [ type, value, start, scanner.pos ];
 265        }
 266        tagIndex++;
 267        tokens.push(token);
 268  
 269        if (type === '#' || type === '^' || type === '$' || type === '<') {
 270          sections.push(token);
 271        } else if (type === '/') {
 272          // Check section nesting.
 273          openSection = sections.pop();
 274  
 275          if (!openSection)
 276            throw new Error('Unopened section "' + value + '" at ' + start);
 277  
 278          if (openSection[1] !== value)
 279            throw new Error('Unclosed section "' + openSection[1] + '" at ' + start);
 280        } else if (type === 'name' || type === '{' || type === '&') {
 281          nonSpace = true;
 282        } else if (type === '=') {
 283          // Set the tags for the next time around.
 284          compileTags(value);
 285        }
 286      }
 287  
 288      stripSpace();
 289  
 290      // Make sure there are no open sections when we're done.
 291      openSection = sections.pop();
 292  
 293      if (openSection)
 294        throw new Error('Unclosed section "' + openSection[1] + '" at ' + scanner.pos);
 295  
 296      return nestTokens(squashTokens(tokens));
 297    }
 298  
 299    /**
 300     * Combines the values of consecutive text tokens in the given `tokens` array
 301     * to a single token.
 302     */
 303    function squashTokens (tokens) {
 304      var squashedTokens = [];
 305  
 306      var token, lastToken;
 307      for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
 308        token = tokens[i];
 309  
 310        if (token) {
 311          if (token[0] === 'text' && lastToken && lastToken[0] === 'text') {
 312            lastToken[1] += token[1];
 313            lastToken[3] = token[3];
 314          } else {
 315            squashedTokens.push(token);
 316            lastToken = token;
 317          }
 318        }
 319      }
 320  
 321      return squashedTokens;
 322    }
 323  
 324    /**
 325     * Forms the given array of `tokens` into a nested tree structure where
 326     * tokens that represent a section have two additional items: 1) an array of
 327     * all tokens that appear in that section and 2) the index in the original
 328     * template that represents the end of that section.
 329     */
 330    function nestTokens (tokens) {
 331      var nestedTokens = [];
 332      var collector = nestedTokens;
 333      var sections = [];
 334  
 335      var token, section;
 336      for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
 337        token = tokens[i];
 338  
 339        switch (token[0]) {
 340          case '$':
 341          case '<':
 342          case '#':
 343          case '^':
 344            collector.push(token);
 345            sections.push(token);
 346            collector = token[4] = [];
 347            break;
 348          case '/':
 349            section = sections.pop();
 350            section[5] = token[2];
 351            collector = sections.length > 0 ? sections[sections.length - 1][4] : nestedTokens;
 352            break;
 353          default:
 354            collector.push(token);
 355        }
 356      }
 357  
 358      return nestedTokens;
 359    }
 360  
 361    /**
 362     * A simple string scanner that is used by the template parser to find
 363     * tokens in template strings.
 364     */
 365    function Scanner (string) {
 366      this.string = string;
 367      this.tail = string;
 368      this.pos = 0;
 369    }
 370  
 371    /**
 372     * Returns `true` if the tail is empty (end of string).
 373     */
 374    Scanner.prototype.eos = function eos () {
 375      return this.tail === '';
 376    };
 377  
 378    /**
 379     * Tries to match the given regular expression at the current position.
 380     * Returns the matched text if it can match, the empty string otherwise.
 381     */
 382    Scanner.prototype.scan = function scan (re) {
 383      var match = this.tail.match(re);
 384  
 385      if (!match || match.index !== 0)
 386        return '';
 387  
 388      var string = match[0];
 389  
 390      this.tail = this.tail.substring(string.length);
 391      this.pos += string.length;
 392  
 393      return string;
 394    };
 395  
 396    /**
 397     * Skips all text until the given regular expression can be matched. Returns
 398     * the skipped string, which is the entire tail if no match can be made.
 399     */
 400    Scanner.prototype.scanUntil = function scanUntil (re) {
 401      var index = this.tail.search(re), match;
 402  
 403      switch (index) {
 404        case -1:
 405          match = this.tail;
 406          this.tail = '';
 407          break;
 408        case 0:
 409          match = '';
 410          break;
 411        default:
 412          match = this.tail.substring(0, index);
 413          this.tail = this.tail.substring(index);
 414      }
 415  
 416      this.pos += match.length;
 417  
 418      return match;
 419    };
 420  
 421    /**
 422     * Represents a rendering context by wrapping a view object and
 423     * maintaining a reference to the parent context.
 424     */
 425    function Context (view, parentContext) {
 426      this.view = view;
 427      this.blocks = {};
 428      this.cache = { '.': this.view };
 429      this.parent = parentContext;
 430    }
 431  
 432    /**
 433     * Creates a new context using the given view with this context
 434     * as the parent.
 435     */
 436    Context.prototype.push = function push (view) {
 437      return new Context(view, this);
 438    };
 439  
 440    /**
 441     * Set a value in the current block context.
 442     */
 443    Context.prototype.setBlockVar = function set (name, value) {
 444      var blocks = this.blocks;
 445  
 446      blocks[name] = value;
 447  
 448      return value;
 449    };
 450  
 451    /**
 452     * Clear all current block vars.
 453     */
 454    Context.prototype.clearBlockVars = function clearBlockVars () {
 455      this.blocks = {};
 456    };
 457  
 458    /**
 459     * Get a value only from the current block context.
 460     */
 461    Context.prototype.getBlockVar = function getBlockVar (name) {
 462      var blocks = this.blocks;
 463  
 464      var value;
 465      if (blocks.hasOwnProperty(name)) {
 466        value = blocks[name];
 467      } else {
 468        if (this.parent) {
 469          value = this.parent.getBlockVar(name);
 470        }
 471      }
 472      // Can return undefined.
 473      return value;
 474    };
 475  
 476    /**
 477     * Returns the value of the given name in this context, traversing
 478     * up the context hierarchy if the value is absent in this context's view.
 479     */
 480    Context.prototype.lookup = function lookup (name) {
 481      var cache = this.cache;
 482  
 483      var value;
 484      if (cache.hasOwnProperty(name)) {
 485        value = cache[name];
 486      } else {
 487        var context = this, intermediateValue, names, index, lookupHit = false;
 488  
 489        while (context) {
 490          if (name.indexOf('.') > 0) {
 491            intermediateValue = context.view;
 492            names = name.split('.');
 493            index = 0;
 494  
 495            /**
 496             * Using the dot notion path in `name`, we descend through the
 497             * nested objects.
 498             *
 499             * To be certain that the lookup has been successful, we have to
 500             * check if the last object in the path actually has the property
 501             * we are looking for. We store the result in `lookupHit`.
 502             *
 503             * This is specially necessary for when the value has been set to
 504             * `undefined` and we want to avoid looking up parent contexts.
 505             *
 506             * In the case where dot notation is used, we consider the lookup
 507             * to be successful even if the last "object" in the path is
 508             * not actually an object but a primitive (e.g., a string, or an
 509             * integer), because it is sometimes useful to access a property
 510             * of an autoboxed primitive, such as the length of a string.
 511             **/
 512            while (intermediateValue != null && index < names.length) {
 513              if (index === names.length - 1)
 514                lookupHit = (
 515                  hasProperty(intermediateValue, names[index])
 516                  || primitiveHasOwnProperty(intermediateValue, names[index])
 517                );
 518  
 519              intermediateValue = intermediateValue[names[index++]];
 520            }
 521          } else {
 522            intermediateValue = context.view[name];
 523  
 524            /**
 525             * Only checking against `hasProperty`, which always returns `false` if
 526             * `context.view` is not an object. Deliberately omitting the check
 527             * against `primitiveHasOwnProperty` if dot notation is not used.
 528             *
 529             * Consider this example:
 530             * ```
 531             * Mustache.render("The length of a football field is {{#length}}{{length}}{{/length}}.", {length: "100 yards"})
 532             * ```
 533             *
 534             * If we were to check also against `primitiveHasOwnProperty`, as we do
 535             * in the dot notation case, then render call would return:
 536             *
 537             * "The length of a football field is 9."
 538             *
 539             * rather than the expected:
 540             *
 541             * "The length of a football field is 100 yards."
 542             **/
 543            lookupHit = hasProperty(context.view, name);
 544          }
 545  
 546          if (lookupHit) {
 547            value = intermediateValue;
 548            break;
 549          }
 550  
 551          context = context.parent;
 552        }
 553  
 554        cache[name] = value;
 555      }
 556  
 557      if (isFunction(value))
 558        value = value.call(this.view);
 559  
 560      return value;
 561    };
 562  
 563    /**
 564     * A Writer knows how to take a stream of tokens and render them to a
 565     * string, given a context. It also maintains a cache of templates to
 566     * avoid the need to parse the same template twice.
 567     */
 568    function Writer () {
 569      this.cache = {};
 570    }
 571  
 572    /**
 573     * Clears all cached templates in this writer.
 574     */
 575    Writer.prototype.clearCache = function clearCache () {
 576      this.cache = {};
 577    };
 578  
 579    /**
 580     * Parses and caches the given `template` according to the given `tags` or
 581     * `mustache.tags` if `tags` is omitted,  and returns the array of tokens
 582     * that is generated from the parse.
 583     */
 584    Writer.prototype.parse = function parse (template, tags) {
 585      var cache = this.cache;
 586      var cacheKey = template + ':' + (tags || mustache.tags).join(':');
 587      var tokens = cache[cacheKey];
 588  
 589      if (tokens == null)
 590        tokens = cache[cacheKey] = parseTemplate(template, tags);
 591  
 592      return tokens;
 593    };
 594  
 595    /**
 596     * High-level method that is used to render the given `template` with
 597     * the given `view`.
 598     *
 599     * The optional `partials` argument may be an object that contains the
 600     * names and templates of partials that are used in the template. It may
 601     * also be a function that is used to load partial templates on the fly
 602     * that takes a single argument: the name of the partial.
 603     *
 604     * If the optional `tags` argument is given here it must be an array with two
 605     * string values: the opening and closing tags used in the template (e.g.
 606     * [ "<%", "%>" ]). The default is to mustache.tags.
 607     */
 608    Writer.prototype.render = function render (template, view, partials, tags) {
 609      var tokens = this.parse(template, tags);
 610      var context = (view instanceof Context) ? view : new Context(view);
 611      return this.renderTokens(tokens, context, partials, template, tags);
 612    };
 613  
 614    /**
 615     * Low-level method that renders the given array of `tokens` using
 616     * the given `context` and `partials`.
 617     *
 618     * Note: The `originalTemplate` is only ever used to extract the portion
 619     * of the original template that was contained in a higher-order section.
 620     * If the template doesn't use higher-order sections, this argument may
 621     * be omitted.
 622     */
 623    Writer.prototype.renderTokens = function renderTokens (tokens, context, partials, originalTemplate, tags) {
 624      var buffer = '';
 625  
 626      var token, symbol, value;
 627      for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
 628        value = undefined;
 629        token = tokens[i];
 630        symbol = token[0];
 631  
 632        if (symbol === '#') value = this.renderSection(token, context, partials, originalTemplate);
 633        else if (symbol === '^') value = this.renderInverted(token, context, partials, originalTemplate);
 634        else if (symbol === '>') value = this.renderPartial(token, context, partials, tags);
 635        else if (symbol === '<') value = this.renderBlock(token, context, partials, originalTemplate);
 636        else if (symbol === '$') value = this.renderBlockVariable(token, context, partials, originalTemplate);
 637        else if (symbol === '&') value = this.unescapedValue(token, context);
 638        else if (symbol === 'name') value = this.escapedValue(token, context);
 639        else if (symbol === 'text') value = this.rawValue(token);
 640  
 641        if (value !== undefined)
 642          buffer += value;
 643      }
 644  
 645      return buffer;
 646    };
 647  
 648    Writer.prototype.renderSection = function renderSection (token, context, partials, originalTemplate) {
 649      var self = this;
 650      var buffer = '';
 651      var value = context.lookup(token[1]);
 652  
 653      // This function is used to render an arbitrary template
 654      // in the current context by higher-order sections.
 655      function subRender (template) {
 656        return self.render(template, context, partials);
 657      }
 658  
 659      if (!value) return;
 660  
 661      if (isArray(value)) {
 662        for (var j = 0, valueLength = value.length; j < valueLength; ++j) {
 663          buffer += this.renderTokens(token[4], context.push(value[j]), partials, originalTemplate);
 664        }
 665      } else if (typeof value === 'object' || typeof value === 'string' || typeof value === 'number') {
 666        buffer += this.renderTokens(token[4], context.push(value), partials, originalTemplate);
 667      } else if (isFunction(value)) {
 668        if (typeof originalTemplate !== 'string')
 669          throw new Error('Cannot use higher-order sections without the original template');
 670  
 671        // Extract the portion of the original template that the section contains.
 672        value = value.call(context.view, originalTemplate.slice(token[3], token[5]), subRender);
 673  
 674        if (value != null)
 675          buffer += value;
 676      } else {
 677        buffer += this.renderTokens(token[4], context, partials, originalTemplate);
 678      }
 679      return buffer;
 680    };
 681  
 682    Writer.prototype.renderInverted = function renderInverted (token, context, partials, originalTemplate) {
 683      var value = context.lookup(token[1]);
 684  
 685      // Use JavaScript's definition of falsy. Include empty arrays.
 686      // See https://github.com/janl/mustache.js/issues/186
 687      if (!value || (isArray(value) && value.length === 0))
 688        return this.renderTokens(token[4], context, partials, originalTemplate);
 689    };
 690  
 691    Writer.prototype.indentPartial = function indentPartial (partial, indentation, lineHasNonSpace) {
 692      var filteredIndentation = indentation.replace(/[^ \t]/g, '');
 693      var partialByNl = partial.split('\n');
 694      for (var i = 0; i < partialByNl.length; i++) {
 695        if (partialByNl[i].length && (i > 0 || !lineHasNonSpace)) {
 696          partialByNl[i] = filteredIndentation + partialByNl[i];
 697        }
 698      }
 699      return partialByNl.join('\n');
 700    };
 701  
 702    Writer.prototype.renderPartial = function renderPartial (token, context, partials, tags) {
 703      if (!partials) return;
 704  
 705      var value = isFunction(partials) ? partials(token[1]) : partials[token[1]];
 706      if (value != null) {
 707        var lineHasNonSpace = token[6];
 708        var tagIndex = token[5];
 709        var indentation = token[4];
 710        var indentedValue = value;
 711        if (tagIndex == 0 && indentation) {
 712          indentedValue = this.indentPartial(value, indentation, lineHasNonSpace);
 713        }
 714        return this.renderTokens(this.parse(indentedValue, tags), context, partials, indentedValue);
 715      }
 716    };
 717  
 718    Writer.prototype.renderBlock = function renderBlock (token, context, partials, originalTemplate) {
 719      if (!partials) return;
 720  
 721      var value = isFunction(partials) ? partials(token[1]) : partials[token[1]];
 722      if (value != null)
 723      // Ignore any wrongly set block vars before we started.
 724        context.clearBlockVars();
 725      // We are only rendering to record the default block variables.
 726      this.renderTokens(token[4], context, partials, originalTemplate);
 727      // Now we render and return the result.
 728      var result = this.renderTokens(this.parse(value), context, partials, value);
 729      // Don't leak the block variables outside this include.
 730      context.clearBlockVars();
 731      return result;
 732    };
 733  
 734    Writer.prototype.renderBlockVariable = function renderBlockVariable (token, context, partials, originalTemplate) {
 735      var value = token[1];
 736  
 737      var exists = context.getBlockVar(value);
 738      if (!exists) {
 739        context.setBlockVar(value, originalTemplate.slice(token[3], token[5]));
 740        return this.renderTokens(token[4], context, partials, originalTemplate);
 741      } else {
 742        return this.renderTokens(this.parse(exists), context, partials, exists);
 743      }
 744    };
 745  
 746    Writer.prototype.unescapedValue = function unescapedValue (token, context) {
 747      var value = context.lookup(token[1]);
 748      if (value != null)
 749        return value;
 750    };
 751  
 752    Writer.prototype.escapedValue = function escapedValue (token, context) {
 753      var value = context.lookup(token[1]);
 754      if (value != null)
 755        return mustache.escape(value);
 756    };
 757  
 758    Writer.prototype.rawValue = function rawValue (token) {
 759      return token[1];
 760    };
 761  
 762    mustache.name = 'mustache.js';
 763    mustache.version = '3.1.0';
 764    mustache.tags = [ '{{', '}}' ];
 765  
 766    // All high-level mustache.* functions use this writer.
 767    var defaultWriter = new Writer();
 768  
 769    /**
 770     * Clears all cached templates in the default writer.
 771     */
 772    mustache.clearCache = function clearCache () {
 773      return defaultWriter.clearCache();
 774    };
 775  
 776    /**
 777     * Parses and caches the given template in the default writer and returns the
 778     * array of tokens it contains. Doing this ahead of time avoids the need to
 779     * parse templates on the fly as they are rendered.
 780     */
 781    mustache.parse = function parse (template, tags) {
 782      return defaultWriter.parse(template, tags);
 783    };
 784  
 785    /**
 786     * Renders the `template` with the given `view` and `partials` using the
 787     * default writer. If the optional `tags` argument is given here it must be an
 788     * array with two string values: the opening and closing tags used in the
 789     * template (e.g. [ "<%", "%>" ]). The default is to mustache.tags.
 790     */
 791    mustache.render = function render (template, view, partials, tags) {
 792      if (typeof template !== 'string') {
 793        throw new TypeError('Invalid template! Template should be a "string" ' +
 794                            'but "' + typeStr(template) + '" was given as the first ' +
 795                            'argument for mustache#render(template, view, partials)');
 796      }
 797  
 798      return defaultWriter.render(template, view, partials, tags);
 799    };
 800  
 801    // This is here for backwards compatibility with 0.4.x.,
 802    /*eslint-disable */ // eslint wants camel cased function name
 803    mustache.to_html = function to_html (template, view, partials, send) {
 804      /*eslint-enable*/
 805  
 806      var result = mustache.render(template, view, partials);
 807  
 808      if (isFunction(send)) {
 809        send(result);
 810      } else {
 811        return result;
 812      }
 813    };
 814  
 815    // Export the escaping function so that the user may override it.
 816    // See https://github.com/janl/mustache.js/issues/244
 817    mustache.escape = escapeHtml;
 818  
 819    // Export these mainly for testing, but also for advanced usage.
 820    mustache.Scanner = Scanner;
 821    mustache.Context = Context;
 822    mustache.Writer = Writer;
 823  
 824    return mustache;
 825  }));
 826  /* jshint ignore:end */