2 * mustache.js - Logic-less {{mustache}} templates with JavaScript
3 * http://github.com/janl/mustache.js
6 /*global define: false*/
8 (function (global, factory) {
9 if (typeof exports === "object" && exports) {
10 factory(exports); // CommonJS
11 } else if (typeof define === "function" && define.amd) {
12 define(['exports'], factory); // AMD
14 factory(global.Mustache = {}); // <script>
16 }(this, function (mustache) {
18 var Object_toString = Object.prototype.toString;
19 var isArray = Array.isArray || function (object) {
20 return Object_toString.call(object) === '[object Array]';
23 function isFunction(object) {
24 return typeof object === 'function';
27 function escapeRegExp(string) {
28 return string.replace(/[\-\[\]{}()*+?.,\\\^$|#\s]/g, "\\$&");
31 // Workaround for https://issues.apache.org/jira/browse/COUCHDB-577
32 // See https://github.com/janl/mustache.js/issues/189
33 var RegExp_test = RegExp.prototype.test;
34 function testRegExp(re, string) {
35 return RegExp_test.call(re, string);
38 var nonSpaceRe = /\S/;
39 function isWhitespace(string) {
40 return !testRegExp(nonSpaceRe, string);
52 function escapeHtml(string) {
53 return String(string).replace(/[&<>"'\/]/g, function (s) {
60 var equalsRe = /\s*=/;
61 var curlyRe = /\s*\}/;
62 var tagRe = /#|\^|\/|>|\{|&|=|!/;
65 * Breaks up the given `template` string into a tree of tokens. If the `tags`
66 * argument is given here it must be an array with two string values: the
67 * opening and closing tags used in the template (e.g. [ "<%", "%>" ]). Of
68 * course, the default is to use mustaches (i.e. mustache.tags).
70 * A token is an array with at least 4 elements. The first element is the
71 * mustache symbol that was used inside the tag, e.g. "#" or "&". If the tag
72 * did not contain a symbol (i.e. {{myValue}}) this element is "name". For
73 * all text that appears outside a symbol this element is "text".
75 * The second element of a token is its "value". For mustache tags this is
76 * whatever else was inside the tag besides the opening symbol. For text tokens
77 * this is the text itself.
79 * The third and fourth elements of the token are the start and end indices,
80 * respectively, of the token in the original template.
82 * Tokens that are the root node of a subtree contain two more elements: 1) an
83 * array of tokens in the subtree and 2) the index in the original template at
84 * which the closing tag for that section begins.
86 function parseTemplate(template, tags) {
90 var sections = []; // Stack to hold section tokens
91 var tokens = []; // Buffer to hold the tokens
92 var spaces = []; // Indices of whitespace tokens on the current line
93 var hasTag = false; // Is there a {{tag}} on the current line?
94 var nonSpace = false; // Is there a non-space char on the current line?
96 // Strips all whitespace tokens array for the current line
97 // if there was a {{#tag}} on it and otherwise only space.
98 function stripSpace() {
99 if (hasTag && !nonSpace) {
100 while (spaces.length)
101 delete tokens[spaces.pop()];
110 var openingTagRe, closingTagRe, closingCurlyRe;
111 function compileTags(tags) {
112 if (typeof tags === 'string')
113 tags = tags.split(spaceRe, 2);
115 if (!isArray(tags) || tags.length !== 2)
116 throw new Error('Invalid tags: ' + tags);
118 openingTagRe = new RegExp(escapeRegExp(tags[0]) + '\\s*');
119 closingTagRe = new RegExp('\\s*' + escapeRegExp(tags[1]));
120 closingCurlyRe = new RegExp('\\s*' + escapeRegExp('}' + tags[1]));
123 compileTags(tags || mustache.tags);
125 var scanner = new Scanner(template);
127 var start, type, value, chr, token, openSection;
128 while (!scanner.eos()) {
131 // Match any text between tags.
132 value = scanner.scanUntil(openingTagRe);
135 for (var i = 0, valueLength = value.length; i < valueLength; ++i) {
136 chr = value.charAt(i);
138 if (isWhitespace(chr)) {
139 spaces.push(tokens.length);
144 tokens.push([ 'text', chr, start, start + 1 ]);
147 // Check for whitespace on the current line.
153 // Match the opening tag.
154 if (!scanner.scan(openingTagRe))
160 type = scanner.scan(tagRe) || 'name';
161 scanner.scan(whiteRe);
163 // Get the tag value.
165 value = scanner.scanUntil(equalsRe);
166 scanner.scan(equalsRe);
167 scanner.scanUntil(closingTagRe);
168 } else if (type === '{') {
169 value = scanner.scanUntil(closingCurlyRe);
170 scanner.scan(curlyRe);
171 scanner.scanUntil(closingTagRe);
174 value = scanner.scanUntil(closingTagRe);
177 // Match the closing tag.
178 if (!scanner.scan(closingTagRe))
179 throw new Error('Unclosed tag at ' + scanner.pos);
181 token = [ type, value, start, scanner.pos ];
184 if (type === '#' || type === '^') {
185 sections.push(token);
186 } else if (type === '/') {
187 // Check section nesting.
188 openSection = sections.pop();
191 throw new Error('Unopened section "' + value + '" at ' + start);
193 if (openSection[1] !== value)
194 throw new Error('Unclosed section "' + openSection[1] + '" at ' + start);
195 } else if (type === 'name' || type === '{' || type === '&') {
197 } else if (type === '=') {
198 // Set the tags for the next time around.
203 // Make sure there are no open sections when we're done.
204 openSection = sections.pop();
207 throw new Error('Unclosed section "' + openSection[1] + '" at ' + scanner.pos);
209 return nestTokens(squashTokens(tokens));
213 * Combines the values of consecutive text tokens in the given `tokens` array
216 function squashTokens(tokens) {
217 var squashedTokens = [];
219 var token, lastToken;
220 for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
224 if (token[0] === 'text' && lastToken && lastToken[0] === 'text') {
225 lastToken[1] += token[1];
226 lastToken[3] = token[3];
228 squashedTokens.push(token);
234 return squashedTokens;
238 * Forms the given array of `tokens` into a nested tree structure where
239 * tokens that represent a section have two additional items: 1) an array of
240 * all tokens that appear in that section and 2) the index in the original
241 * template that represents the end of that section.
243 function nestTokens(tokens) {
244 var nestedTokens = [];
245 var collector = nestedTokens;
249 for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
255 collector.push(token);
256 sections.push(token);
257 collector = token[4] = [];
260 section = sections.pop();
261 section[5] = token[2];
262 collector = sections.length > 0 ? sections[sections.length - 1][4] : nestedTokens;
265 collector.push(token);
273 * A simple string scanner that is used by the template parser to find
274 * tokens in template strings.
276 function Scanner(string) {
277 this.string = string;
283 * Returns `true` if the tail is empty (end of string).
285 Scanner.prototype.eos = function () {
286 return this.tail === "";
290 * Tries to match the given regular expression at the current position.
291 * Returns the matched text if it can match, the empty string otherwise.
293 Scanner.prototype.scan = function (re) {
294 var match = this.tail.match(re);
296 if (!match || match.index !== 0)
299 var string = match[0];
301 this.tail = this.tail.substring(string.length);
302 this.pos += string.length;
308 * Skips all text until the given regular expression can be matched. Returns
309 * the skipped string, which is the entire tail if no match can be made.
311 Scanner.prototype.scanUntil = function (re) {
312 var index = this.tail.search(re), match;
323 match = this.tail.substring(0, index);
324 this.tail = this.tail.substring(index);
327 this.pos += match.length;
333 * Represents a rendering context by wrapping a view object and
334 * maintaining a reference to the parent context.
336 function Context(view, parentContext) {
337 this.view = view == null ? {} : view;
338 this.cache = { '.': this.view };
339 this.parent = parentContext;
343 * Creates a new context using the given view with this context
346 Context.prototype.push = function (view) {
347 return new Context(view, this);
351 * Returns the value of the given name in this context, traversing
352 * up the context hierarchy if the value is absent in this context's view.
354 Context.prototype.lookup = function (name) {
355 var cache = this.cache;
361 var context = this, names, index;
364 if (name.indexOf('.') > 0) {
365 value = context.view;
366 names = name.split('.');
369 while (value != null && index < names.length)
370 value = value[names[index++]];
371 } else if (typeof context.view == 'object') {
372 value = context.view[name];
378 context = context.parent;
384 if (isFunction(value))
385 value = value.call(this.view);
391 * A Writer knows how to take a stream of tokens and render them to a
392 * string, given a context. It also maintains a cache of templates to
393 * avoid the need to parse the same template twice.
400 * Clears all cached templates in this writer.
402 Writer.prototype.clearCache = function () {
407 * Parses and caches the given `template` and returns the array of tokens
408 * that is generated from the parse.
410 Writer.prototype.parse = function (template, tags) {
411 var cache = this.cache;
412 var tokens = cache[template];
415 tokens = cache[template] = parseTemplate(template, tags);
421 * High-level method that is used to render the given `template` with
424 * The optional `partials` argument may be an object that contains the
425 * names and templates of partials that are used in the template. It may
426 * also be a function that is used to load partial templates on the fly
427 * that takes a single argument: the name of the partial.
429 Writer.prototype.render = function (template, view, partials) {
430 var tokens = this.parse(template);
431 var context = (view instanceof Context) ? view : new Context(view);
432 return this.renderTokens(tokens, context, partials, template);
436 * Low-level method that renders the given array of `tokens` using
437 * the given `context` and `partials`.
439 * Note: The `originalTemplate` is only ever used to extract the portion
440 * of the original template that was contained in a higher-order section.
441 * If the template doesn't use higher-order sections, this argument may
444 Writer.prototype.renderTokens = function (tokens, context, partials, originalTemplate) {
447 // This function is used to render an arbitrary template
448 // in the current context by higher-order sections.
450 function subRender(template) {
451 return self.render(template, context, partials);
455 for (var i = 0, numTokens = tokens.length; i < numTokens; ++i) {
460 value = context.lookup(token[1]);
465 if (isArray(value)) {
466 for (var j = 0, valueLength = value.length; j < valueLength; ++j) {
467 buffer += this.renderTokens(token[4], context.push(value[j]), partials, originalTemplate);
469 } else if (typeof value === 'object' || typeof value === 'string') {
470 buffer += this.renderTokens(token[4], context.push(value), partials, originalTemplate);
471 } else if (isFunction(value)) {
472 if (typeof originalTemplate !== 'string')
473 throw new Error('Cannot use higher-order sections without the original template');
475 // Extract the portion of the original template that the section contains.
476 value = value.call(context.view, originalTemplate.slice(token[3], token[5]), subRender);
481 buffer += this.renderTokens(token[4], context, partials, originalTemplate);
486 value = context.lookup(token[1]);
488 // Use JavaScript's definition of falsy. Include empty arrays.
489 // See https://github.com/janl/mustache.js/issues/186
490 if (!value || (isArray(value) && value.length === 0))
491 buffer += this.renderTokens(token[4], context, partials, originalTemplate);
498 value = isFunction(partials) ? partials(token[1]) : partials[token[1]];
501 buffer += this.renderTokens(this.parse(value), context, partials, value);
505 value = context.lookup(token[1]);
512 value = context.lookup(token[1]);
515 buffer += mustache.escape(value);
527 mustache.name = "mustache.js";
528 mustache.version = "0.8.2";
529 mustache.tags = [ "{{", "}}" ];
531 // All high-level mustache.* functions use this writer.
532 var defaultWriter = new Writer();
535 * Clears all cached templates in the default writer.
537 mustache.clearCache = function () {
538 return defaultWriter.clearCache();
542 * Parses and caches the given template in the default writer and returns the
543 * array of tokens it contains. Doing this ahead of time avoids the need to
544 * parse templates on the fly as they are rendered.
546 mustache.parse = function (template, tags) {
547 return defaultWriter.parse(template, tags);
551 * Renders the `template` with the given `view` and `partials` using the
554 mustache.render = function (template, view, partials) {
555 return defaultWriter.render(template, view, partials);
558 // This is here for backwards compatibility with 0.4.x.
559 mustache.to_html = function (template, view, partials, send) {
560 var result = mustache.render(template, view, partials);
562 if (isFunction(send)) {
569 // Export the escaping function so that the user may override it.
570 // See https://github.com/janl/mustache.js/issues/244
571 mustache.escape = escapeHtml;
573 // Export these mainly for testing, but also for advanced usage.
574 mustache.Scanner = Scanner;
575 mustache.Context = Context;
576 mustache.Writer = Writer;