1.underscore.js ?源碼

// Underscore.js 1.8.3 // http://underscorejs.org // (c) 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors // Underscore may be freely distributed under the MIT license.(function() {// Baseline setup// --------------// Establish the root object, `window` in the browser, or `exports` on the server.var root = this;// Save the previous value of the `_` variable.var previousUnderscore = root._;// Save bytes in the minified (but not gzipped) version:var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;// Create quick reference variables for speed access to core prototypes.varpush = ArrayProto.push,slice = ArrayProto.slice,toString = ObjProto.toString,hasOwnProperty = ObjProto.hasOwnProperty;// All **ECMAScript 5** native function implementations that we hope to use// are declared here.varnativeIsArray = Array.isArray,nativeKeys = Object.keys,nativeBind = FuncProto.bind,nativeCreate = Object.create;// Naked function reference for surrogate-prototype-swapping.var Ctor = function(){};// Create a safe reference to the Underscore object for use below.var _ = function(obj) {if (obj instanceof _) return obj;if (!(this instanceof _)) return new _(obj);this._wrapped = obj;};// Export the Underscore object for **Node.js**, with// backwards-compatibility for the old `require()` API. If we're in// the browser, add `_` as a global object.if (typeof exports !== 'undefined') {if (typeof module !== 'undefined' && module.exports) {exports = module.exports = _;}exports._ = _;} else {root._ = _;}// Current version._.VERSION = '1.8.3';// Internal function that returns an efficient (for current engines) version// of the passed-in callback, to be repeatedly applied in other Underscore// functions.var optimizeCb = function(func, context, argCount) {if (context === void 0) return func;switch (argCount == null ? 3 : argCount) {case 1: return function(value) {return func.call(context, value);};case 2: return function(value, other) {return func.call(context, value, other);};case 3: return function(value, index, collection) {return func.call(context, value, index, collection);};case 4: return function(accumulator, value, index, collection) {return func.call(context, accumulator, value, index, collection);};}return function() {return func.apply(context, arguments);};};// A mostly-internal function to generate callbacks that can be applied// to each element in a collection, returning the desired result 鈥� either// identity, an arbitrary callback, a property matcher, or a property accessor.var cb = function(value, context, argCount) {if (value == null) return _.identity;if (_.isFunction(value)) return optimizeCb(value, context, argCount);if (_.isObject(value)) return _.matcher(value);return _.property(value);};_.iteratee = function(value, context) {return cb(value, context, Infinity);};// An internal function for creating assigner functions.var createAssigner = function(keysFunc, undefinedOnly) {return function(obj) {var length = arguments.length;if (length < 2 || obj == null) return obj;for (var index = 1; index < length; index++) {var source = arguments[index],keys = keysFunc(source),l = keys.length;for (var i = 0; i < l; i++) {var key = keys[i];if (!undefinedOnly || obj[key] === void 0) obj[key] = source[key];}}return obj;};};// An internal function for creating a new object that inherits from another.var baseCreate = function(prototype) {if (!_.isObject(prototype)) return {};if (nativeCreate) return nativeCreate(prototype);Ctor.prototype = prototype;var result = new Ctor;Ctor.prototype = null;return result;};var property = function(key) {return function(obj) {return obj == null ? void 0 : obj[key];};};// Helper for collection methods to determine whether a collection// should be iterated as an array or as an object// Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength// Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;var getLength = property('length');var isArrayLike = function(collection) {var length = getLength(collection);return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX;};// Collection Functions// --------------------// The cornerstone, an `each` implementation, aka `forEach`.// Handles raw objects in addition to array-likes. Treats all// sparse array-likes as if they were dense._.each = _.forEach = function(obj, iteratee, context) {iteratee = optimizeCb(iteratee, context);var i, length;if (isArrayLike(obj)) {for (i = 0, length = obj.length; i < length; i++) {iteratee(obj[i], i, obj);}} else {var keys = _.keys(obj);for (i = 0, length = keys.length; i < length; i++) {iteratee(obj[keys[i]], keys[i], obj);}}return obj;};// Return the results of applying the iteratee to each element._.map = _.collect = function(obj, iteratee, context) {iteratee = cb(iteratee, context);var keys = !isArrayLike(obj) && _.keys(obj),length = (keys || obj).length,results = Array(length);for (var index = 0; index < length; index++) {var currentKey = keys ? keys[index] : index;results[index] = iteratee(obj[currentKey], currentKey, obj);}return results;};// Create a reducing function iterating left or right.function createReduce(dir) {// Optimized iterator function as using arguments.length// in the main function will deoptimize the, see #1991.function iterator(obj, iteratee, memo, keys, index, length) {for (; index >= 0 && index < length; index += dir) {var currentKey = keys ? keys[index] : index;memo = iteratee(memo, obj[currentKey], currentKey, obj);}return memo;}return function(obj, iteratee, memo, context) {iteratee = optimizeCb(iteratee, context, 4);var keys = !isArrayLike(obj) && _.keys(obj),length = (keys || obj).length,index = dir > 0 ? 0 : length - 1;// Determine the initial value if none is provided.if (arguments.length < 3) {memo = obj[keys ? keys[index] : index];index += dir;}return iterator(obj, iteratee, memo, keys, index, length);};}// **Reduce** builds up a single result from a list of values, aka `inject`,// or `foldl`._.reduce = _.foldl = _.inject = createReduce(1);// The right-associative version of reduce, also known as `foldr`._.reduceRight = _.foldr = createReduce(-1);// Return the first value which passes a truth test. Aliased as `detect`._.find = _.detect = function(obj, predicate, context) {var key;if (isArrayLike(obj)) {key = _.findIndex(obj, predicate, context);} else {key = _.findKey(obj, predicate, context);}if (key !== void 0 && key !== -1) return obj[key];};// Return all the elements that pass a truth test.// Aliased as `select`._.filter = _.select = function(obj, predicate, context) {var results = [];predicate = cb(predicate, context);_.each(obj, function(value, index, list) {if (predicate(value, index, list)) results.push(value);});return results;};// Return all the elements for which a truth test fails._.reject = function(obj, predicate, context) {return _.filter(obj, _.negate(cb(predicate)), context);};// Determine whether all of the elements match a truth test.// Aliased as `all`._.every = _.all = function(obj, predicate, context) {predicate = cb(predicate, context);var keys = !isArrayLike(obj) && _.keys(obj),length = (keys || obj).length;for (var index = 0; index < length; index++) {var currentKey = keys ? keys[index] : index;if (!predicate(obj[currentKey], currentKey, obj)) return false;}return true;};// Determine if at least one element in the object matches a truth test.// Aliased as `any`._.some = _.any = function(obj, predicate, context) {predicate = cb(predicate, context);var keys = !isArrayLike(obj) && _.keys(obj),length = (keys || obj).length;for (var index = 0; index < length; index++) {var currentKey = keys ? keys[index] : index;if (predicate(obj[currentKey], currentKey, obj)) return true;}return false;};// Determine if the array or object contains a given item (using `===`).// Aliased as `includes` and `include`._.contains = _.includes = _.include = function(obj, item, fromIndex, guard) {if (!isArrayLike(obj)) obj = _.values(obj);if (typeof fromIndex != 'number' || guard) fromIndex = 0;return _.indexOf(obj, item, fromIndex) >= 0;};// Invoke a method (with arguments) on every item in a collection._.invoke = function(obj, method) {var args = slice.call(arguments, 2);var isFunc = _.isFunction(method);return _.map(obj, function(value) {var func = isFunc ? method : value[method];return func == null ? func : func.apply(value, args);});};// Convenience version of a common use case of `map`: fetching a property._.pluck = function(obj, key) {return _.map(obj, _.property(key));};// Convenience version of a common use case of `filter`: selecting only objects// containing specific `key:value` pairs._.where = function(obj, attrs) {return _.filter(obj, _.matcher(attrs));};// Convenience version of a common use case of `find`: getting the first object// containing specific `key:value` pairs._.findWhere = function(obj, attrs) {return _.find(obj, _.matcher(attrs));};// Return the maximum element (or element-based computation)._.max = function(obj, iteratee, context) {var result = -Infinity, lastComputed = -Infinity,value, computed;if (iteratee == null && obj != null) {obj = isArrayLike(obj) ? obj : _.values(obj);for (var i = 0, length = obj.length; i < length; i++) {value = obj[i];if (value > result) {result = value;}}} else {iteratee = cb(iteratee, context);_.each(obj, function(value, index, list) {computed = iteratee(value, index, list);if (computed > lastComputed || computed === -Infinity && result === -Infinity) {result = value;lastComputed = computed;}});}return result;};// Return the minimum element (or element-based computation)._.min = function(obj, iteratee, context) {var result = Infinity, lastComputed = Infinity,value, computed;if (iteratee == null && obj != null) {obj = isArrayLike(obj) ? obj : _.values(obj);for (var i = 0, length = obj.length; i < length; i++) {value = obj[i];if (value < result) {result = value;}}} else {iteratee = cb(iteratee, context);_.each(obj, function(value, index, list) {computed = iteratee(value, index, list);if (computed < lastComputed || computed === Infinity && result === Infinity) {result = value;lastComputed = computed;}});}return result;};// Shuffle a collection, using the modern version of the// [Fisher-Yates shuffle](http://en.wikipedia.org/wiki/Fisher鈥揧ates_shuffle)._.shuffle = function(obj) {var set = isArrayLike(obj) ? obj : _.values(obj);var length = set.length;var shuffled = Array(length);for (var index = 0, rand; index < length; index++) {rand = _.random(0, index);if (rand !== index) shuffled[index] = shuffled[rand];shuffled[rand] = set[index];}return shuffled;};// Sample **n** random values from a collection.// If **n** is not specified, returns a single random element.// The internal `guard` argument allows it to work with `map`._.sample = function(obj, n, guard) {if (n == null || guard) {if (!isArrayLike(obj)) obj = _.values(obj);return obj[_.random(obj.length - 1)];}return _.shuffle(obj).slice(0, Math.max(0, n));};// Sort the object's values by a criterion produced by an iteratee._.sortBy = function(obj, iteratee, context) {iteratee = cb(iteratee, context);return _.pluck(_.map(obj, function(value, index, list) {return {value: value,index: index,criteria: iteratee(value, index, list)};}).sort(function(left, right) {var a = left.criteria;var b = right.criteria;if (a !== b) {if (a > b || a === void 0) return 1;if (a < b || b === void 0) return -1;}return left.index - right.index;}), 'value');};// An internal function used for aggregate "group by" operations.var group = function(behavior) {return function(obj, iteratee, context) {var result = {};iteratee = cb(iteratee, context);_.each(obj, function(value, index) {var key = iteratee(value, index, obj);behavior(result, value, key);});return result;};};// Groups the object's values by a criterion. Pass either a string attribute// to group by, or a function that returns the criterion._.groupBy = group(function(result, value, key) {if (_.has(result, key)) result[key].push(value); else result[key] = [value];});// Indexes the object's values by a criterion, similar to `groupBy`, but for// when you know that your index values will be unique._.indexBy = group(function(result, value, key) {result[key] = value;});// Counts instances of an object that group by a certain criterion. Pass// either a string attribute to count by, or a function that returns the// criterion._.countBy = group(function(result, value, key) {if (_.has(result, key)) result[key]++; else result[key] = 1;});// Safely create a real, live array from anything iterable._.toArray = function(obj) {if (!obj) return [];if (_.isArray(obj)) return slice.call(obj);if (isArrayLike(obj)) return _.map(obj, _.identity);return _.values(obj);};// Return the number of elements in an object._.size = function(obj) {if (obj == null) return 0;return isArrayLike(obj) ? obj.length : _.keys(obj).length;};// Split a collection into two arrays: one whose elements all satisfy the given// predicate, and one whose elements all do not satisfy the predicate._.partition = function(obj, predicate, context) {predicate = cb(predicate, context);var pass = [], fail = [];_.each(obj, function(value, key, obj) {(predicate(value, key, obj) ? pass : fail).push(value);});return [pass, fail];};// Array Functions// ---------------// Get the first element of an array. Passing **n** will return the first N// values in the array. Aliased as `head` and `take`. The **guard** check// allows it to work with `_.map`._.first = _.head = _.take = function(array, n, guard) {if (array == null) return void 0;if (n == null || guard) return array[0];return _.initial(array, array.length - n);};// Returns everything but the last entry of the array. Especially useful on// the arguments object. Passing **n** will return all the values in// the array, excluding the last N._.initial = function(array, n, guard) {return slice.call(array, 0, Math.max(0, array.length - (n == null || guard ? 1 : n)));};// Get the last element of an array. Passing **n** will return the last N// values in the array._.last = function(array, n, guard) {if (array == null) return void 0;if (n == null || guard) return array[array.length - 1];return _.rest(array, Math.max(0, array.length - n));};// Returns everything but the first entry of the array. Aliased as `tail` and `drop`.// Especially useful on the arguments object. Passing an **n** will return// the rest N values in the array._.rest = _.tail = _.drop = function(array, n, guard) {return slice.call(array, n == null || guard ? 1 : n);};// Trim out all falsy values from an array._.compact = function(array) {return _.filter(array, _.identity);};// Internal implementation of a recursive `flatten` function.var flatten = function(input, shallow, strict, startIndex) {var output = [], idx = 0;for (var i = startIndex || 0, length = getLength(input); i < length; i++) {var value = input[i];if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) {//flatten current level of array or arguments objectif (!shallow) value = flatten(value, shallow, strict);var j = 0, len = value.length;output.length += len;while (j < len) {output[idx++] = value[j++];}} else if (!strict) {output[idx++] = value;}}return output;};// Flatten out an array, either recursively (by default), or just one level._.flatten = function(array, shallow) {return flatten(array, shallow, false);};// Return a version of the array that does not contain the specified value(s)._.without = function(array) {return _.difference(array, slice.call(arguments, 1));};// Produce a duplicate-free version of the array. If the array has already// been sorted, you have the option of using a faster algorithm.// Aliased as `unique`._.uniq = _.unique = function(array, isSorted, iteratee, context) {if (!_.isBoolean(isSorted)) {context = iteratee;iteratee = isSorted;isSorted = false;}if (iteratee != null) iteratee = cb(iteratee, context);var result = [];var seen = [];for (var i = 0, length = getLength(array); i < length; i++) {var value = array[i],computed = iteratee ? iteratee(value, i, array) : value;if (isSorted) {if (!i || seen !== computed) result.push(value);seen = computed;} else if (iteratee) {if (!_.contains(seen, computed)) {seen.push(computed);result.push(value);}} else if (!_.contains(result, value)) {result.push(value);}}return result;};// Produce an array that contains the union: each distinct element from all of// the passed-in arrays._.union = function() {return _.uniq(flatten(arguments, true, true));};// Produce an array that contains every item shared between all the// passed-in arrays._.intersection = function(array) {var result = [];var argsLength = arguments.length;for (var i = 0, length = getLength(array); i < length; i++) {var item = array[i];if (_.contains(result, item)) continue;for (var j = 1; j < argsLength; j++) {if (!_.contains(arguments[j], item)) break;}if (j === argsLength) result.push(item);}return result;};// Take the difference between one array and a number of other arrays.// Only the elements present in just the first array will remain._.difference = function(array) {var rest = flatten(arguments, true, true, 1);return _.filter(array, function(value){return !_.contains(rest, value);});};// Zip together multiple lists into a single array -- elements that share// an index go together._.zip = function() {return _.unzip(arguments);};// Complement of _.zip. Unzip accepts an array of arrays and groups// each array's elements on shared indices_.unzip = function(array) {var length = array && _.max(array, getLength).length || 0;var result = Array(length);for (var index = 0; index < length; index++) {result[index] = _.pluck(array, index);}return result;};// Converts lists into objects. Pass either a single array of `[key, value]`// pairs, or two parallel arrays of the same length -- one of keys, and one of// the corresponding values._.object = function(list, values) {var result = {};for (var i = 0, length = getLength(list); i < length; i++) {if (values) {result[list[i]] = values[i];} else {result[list[i][0]] = list[i][1];}}return result;};// Generator function to create the findIndex and findLastIndex functionsfunction createPredicateIndexFinder(dir) {return function(array, predicate, context) {predicate = cb(predicate, context);var length = getLength(array);var index = dir > 0 ? 0 : length - 1;for (; index >= 0 && index < length; index += dir) {if (predicate(array[index], index, array)) return index;}return -1;};}// Returns the first index on an array-like that passes a predicate test_.findIndex = createPredicateIndexFinder(1);_.findLastIndex = createPredicateIndexFinder(-1);// Use a comparator function to figure out the smallest index at which// an object should be inserted so as to maintain order. Uses binary search._.sortedIndex = function(array, obj, iteratee, context) {iteratee = cb(iteratee, context, 1);var value = iteratee(obj);var low = 0, high = getLength(array);while (low < high) {var mid = Math.floor((low + high) / 2);if (iteratee(array[mid]) < value) low = mid + 1; else high = mid;}return low;};// Generator function to create the indexOf and lastIndexOf functionsfunction createIndexFinder(dir, predicateFind, sortedIndex) {return function(array, item, idx) {var i = 0, length = getLength(array);if (typeof idx == 'number') {if (dir > 0) {i = idx >= 0 ? idx : Math.max(idx + length, i);} else {length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1;}} else if (sortedIndex && idx && length) {idx = sortedIndex(array, item);return array[idx] === item ? idx : -1;}if (item !== item) {idx = predicateFind(slice.call(array, i, length), _.isNaN);return idx >= 0 ? idx + i : -1;}for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) {if (array[idx] === item) return idx;}return -1;};}// Return the position of the first occurrence of an item in an array,// or -1 if the item is not included in the array.// If the array is large and already in sort order, pass `true`// for **isSorted** to use binary search._.indexOf = createIndexFinder(1, _.findIndex, _.sortedIndex);_.lastIndexOf = createIndexFinder(-1, _.findLastIndex);// Generate an integer Array containing an arithmetic progression. A port of// the native Python `range()` function. See// [the Python documentation](http://docs.python.org/library/functions.html#range)._.range = function(start, stop, step) {if (stop == null) {stop = start || 0;start = 0;}step = step || 1;var length = Math.max(Math.ceil((stop - start) / step), 0);var range = Array(length);for (var idx = 0; idx < length; idx++, start += step) {range[idx] = start;}return range;};// Function (ahem) Functions// ------------------// Determines whether to execute a function as a constructor// or a normal function with the provided argumentsvar executeBound = function(sourceFunc, boundFunc, context, callingContext, args) {if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args);var self = baseCreate(sourceFunc.prototype);var result = sourceFunc.apply(self, args);if (_.isObject(result)) return result;return self;};// Create a function bound to a given object (assigning `this`, and arguments,// optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if// available._.bind = function(func, context) {if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function');var args = slice.call(arguments, 2);var bound = function() {return executeBound(func, bound, context, this, args.concat(slice.call(arguments)));};return bound;};// Partially apply a function by creating a version that has had some of its// arguments pre-filled, without changing its dynamic `this` context. _ acts// as a placeholder, allowing any combination of arguments to be pre-filled._.partial = function(func) {var boundArgs = slice.call(arguments, 1);var bound = function() {var position = 0, length = boundArgs.length;var args = Array(length);for (var i = 0; i < length; i++) {args[i] = boundArgs[i] === _ ? arguments[position++] : boundArgs[i];}while (position < arguments.length) args.push(arguments[position++]);return executeBound(func, bound, this, this, args);};return bound;};// Bind a number of an object's methods to that object. Remaining arguments// are the method names to be bound. Useful for ensuring that all callbacks// defined on an object belong to it._.bindAll = function(obj) {var i, length = arguments.length, key;if (length <= 1) throw new Error('bindAll must be passed function names');for (i = 1; i < length; i++) {key = arguments[i];obj[key] = _.bind(obj[key], obj);}return obj;};// Memoize an expensive function by storing its results._.memoize = function(func, hasher) {var memoize = function(key) {var cache = memoize.cache;var address = '' + (hasher ? hasher.apply(this, arguments) : key);if (!_.has(cache, address)) cache[address] = func.apply(this, arguments);return cache[address];};memoize.cache = {};return memoize;};// Delays a function for the given number of milliseconds, and then calls// it with the arguments supplied._.delay = function(func, wait) {var args = slice.call(arguments, 2);return setTimeout(function(){return func.apply(null, args);}, wait);};// Defers a function, scheduling it to run after the current call stack has// cleared._.defer = _.partial(_.delay, _, 1);// Returns a function, that, when invoked, will only be triggered at most once// during a given window of time. Normally, the throttled function will run// as much as it can, without ever going more than once per `wait` duration;// but if you'd like to disable the execution on the leading edge, pass// `{leading: false}`. To disable execution on the trailing edge, ditto._.throttle = function(func, wait, options) {var context, args, result;var timeout = null;var previous = 0;if (!options) options = {};var later = function() {previous = options.leading === false ? 0 : _.now();timeout = null;result = func.apply(context, args);if (!timeout) context = args = null;};return function() {var now = _.now();if (!previous && options.leading === false) previous = now;var remaining = wait - (now - previous);context = this;args = arguments;if (remaining <= 0 || remaining > wait) {if (timeout) {clearTimeout(timeout);timeout = null;}previous = now;result = func.apply(context, args);if (!timeout) context = args = null;} else if (!timeout && options.trailing !== false) {timeout = setTimeout(later, remaining);}return result;};};// Returns a function, that, as long as it continues to be invoked, will not// be triggered. The function will be called after it stops being called for// N milliseconds. If `immediate` is passed, trigger the function on the// leading edge, instead of the trailing._.debounce = function(func, wait, immediate) {var timeout, args, context, timestamp, result;var later = function() {var last = _.now() - timestamp;if (last < wait && last >= 0) {timeout = setTimeout(later, wait - last);} else {timeout = null;if (!immediate) {result = func.apply(context, args);if (!timeout) context = args = null;}}};return function() {context = this;args = arguments;timestamp = _.now();var callNow = immediate && !timeout;if (!timeout) timeout = setTimeout(later, wait);if (callNow) {result = func.apply(context, args);context = args = null;}return result;};};// Returns the first function passed as an argument to the second,// allowing you to adjust arguments, run code before and after, and// conditionally execute the original function._.wrap = function(func, wrapper) {return _.partial(wrapper, func);};// Returns a negated version of the passed-in predicate._.negate = function(predicate) {return function() {return !predicate.apply(this, arguments);};};// Returns a function that is the composition of a list of functions, each// consuming the return value of the function that follows._.compose = function() {var args = arguments;var start = args.length - 1;return function() {var i = start;var result = args[start].apply(this, arguments);while (i--) result = args[i].call(this, result);return result;};};// Returns a function that will only be executed on and after the Nth call._.after = function(times, func) {return function() {if (--times < 1) {return func.apply(this, arguments);}};};// Returns a function that will only be executed up to (but not including) the Nth call._.before = function(times, func) {var memo;return function() {if (--times > 0) {memo = func.apply(this, arguments);}if (times <= 1) func = null;return memo;};};// Returns a function that will be executed at most one time, no matter how// often you call it. Useful for lazy initialization._.once = _.partial(_.before, 2);// Object Functions// ----------------// Keys in IE < 9 that won't be iterated by `for key in ...` and thus missed.var hasEnumBug = !{toString: null}.propertyIsEnumerable('toString');var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString','propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];function collectNonEnumProps(obj, keys) {var nonEnumIdx = nonEnumerableProps.length;var constructor = obj.constructor;var proto = (_.isFunction(constructor) && constructor.prototype) || ObjProto;// Constructor is a special case.var prop = 'constructor';if (_.has(obj, prop) && !_.contains(keys, prop)) keys.push(prop);while (nonEnumIdx--) {prop = nonEnumerableProps[nonEnumIdx];if (prop in obj && obj[prop] !== proto[prop] && !_.contains(keys, prop)) {keys.push(prop);}}}// Retrieve the names of an object's own properties.// Delegates to **ECMAScript 5**'s native `Object.keys`_.keys = function(obj) {if (!_.isObject(obj)) return [];if (nativeKeys) return nativeKeys(obj);var keys = [];for (var key in obj) if (_.has(obj, key)) keys.push(key);// Ahem, IE < 9.if (hasEnumBug) collectNonEnumProps(obj, keys);return keys;};// Retrieve all the property names of an object._.allKeys = function(obj) {if (!_.isObject(obj)) return [];var keys = [];for (var key in obj) keys.push(key);// Ahem, IE < 9.if (hasEnumBug) collectNonEnumProps(obj, keys);return keys;};// Retrieve the values of an object's properties._.values = function(obj) {var keys = _.keys(obj);var length = keys.length;var values = Array(length);for (var i = 0; i < length; i++) {values[i] = obj[keys[i]];}return values;};// Returns the results of applying the iteratee to each element of the object// In contrast to _.map it returns an object_.mapObject = function(obj, iteratee, context) {iteratee = cb(iteratee, context);var keys = _.keys(obj),length = keys.length,results = {},currentKey;for (var index = 0; index < length; index++) {currentKey = keys[index];results[currentKey] = iteratee(obj[currentKey], currentKey, obj);}return results;};// Convert an object into a list of `[key, value]` pairs._.pairs = function(obj) {var keys = _.keys(obj);var length = keys.length;var pairs = Array(length);for (var i = 0; i < length; i++) {pairs[i] = [keys[i], obj[keys[i]]];}return pairs;};// Invert the keys and values of an object. The values must be serializable._.invert = function(obj) {var result = {};var keys = _.keys(obj);for (var i = 0, length = keys.length; i < length; i++) {result[obj[keys[i]]] = keys[i];}return result;};// Return a sorted list of the function names available on the object.// Aliased as `methods`_.functions = _.methods = function(obj) {var names = [];for (var key in obj) {if (_.isFunction(obj[key])) names.push(key);}return names.sort();};// Extend a given object with all the properties in passed-in object(s)._.extend = createAssigner(_.allKeys);// Assigns a given object with all the own properties in the passed-in object(s)// (https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign)_.extendOwn = _.assign = createAssigner(_.keys);// Returns the first key on an object that passes a predicate test_.findKey = function(obj, predicate, context) {predicate = cb(predicate, context);var keys = _.keys(obj), key;for (var i = 0, length = keys.length; i < length; i++) {key = keys[i];if (predicate(obj[key], key, obj)) return key;}};// Return a copy of the object only containing the whitelisted properties._.pick = function(object, oiteratee, context) {var result = {}, obj = object, iteratee, keys;if (obj == null) return result;if (_.isFunction(oiteratee)) {keys = _.allKeys(obj);iteratee = optimizeCb(oiteratee, context);} else {keys = flatten(arguments, false, false, 1);iteratee = function(value, key, obj) { return key in obj; };obj = Object(obj);}for (var i = 0, length = keys.length; i < length; i++) {var key = keys[i];var value = obj[key];if (iteratee(value, key, obj)) result[key] = value;}return result;};// Return a copy of the object without the blacklisted properties._.omit = function(obj, iteratee, context) {if (_.isFunction(iteratee)) {iteratee = _.negate(iteratee);} else {var keys = _.map(flatten(arguments, false, false, 1), String);iteratee = function(value, key) {return !_.contains(keys, key);};}return _.pick(obj, iteratee, context);};// Fill in a given object with default properties._.defaults = createAssigner(_.allKeys, true);// Creates an object that inherits from the given prototype object.// If additional properties are provided then they will be added to the// created object._.create = function(prototype, props) {var result = baseCreate(prototype);if (props) _.extendOwn(result, props);return result;};// Create a (shallow-cloned) duplicate of an object._.clone = function(obj) {if (!_.isObject(obj)) return obj;return _.isArray(obj) ? obj.slice() : _.extend({}, obj);};// Invokes interceptor with the obj, and then returns obj.// The primary purpose of this method is to "tap into" a method chain, in// order to perform operations on intermediate results within the chain._.tap = function(obj, interceptor) {interceptor(obj);return obj;};// Returns whether an object has a given set of `key:value` pairs._.isMatch = function(object, attrs) {var keys = _.keys(attrs), length = keys.length;if (object == null) return !length;var obj = Object(object);for (var i = 0; i < length; i++) {var key = keys[i];if (attrs[key] !== obj[key] || !(key in obj)) return false;}return true;};// Internal recursive comparison function for `isEqual`.var eq = function(a, b, aStack, bStack) {// Identical objects are equal. `0 === -0`, but they aren't identical.// See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal).if (a === b) return a !== 0 || 1 / a === 1 / b;// A strict comparison is necessary because `null == undefined`.if (a == null || b == null) return a === b;// Unwrap any wrapped objects.if (a instanceof _) a = a._wrapped;if (b instanceof _) b = b._wrapped;// Compare `[[Class]]` names.var className = toString.call(a);if (className !== toString.call(b)) return false;switch (className) {// Strings, numbers, regular expressions, dates, and booleans are compared by value.case '[object RegExp]':// RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i')case '[object String]':// Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is// equivalent to `new String("5")`.return '' + a === '' + b;case '[object Number]':// `NaN`s are equivalent, but non-reflexive.// Object(NaN) is equivalent to NaNif (+a !== +a) return +b !== +b;// An `egal` comparison is performed for other numeric values.return +a === 0 ? 1 / +a === 1 / b : +a === +b;case '[object Date]':case '[object Boolean]':// Coerce dates and booleans to numeric primitive values. Dates are compared by their// millisecond representations. Note that invalid dates with millisecond representations// of `NaN` are not equivalent.return +a === +b;}var areArrays = className === '[object Array]';if (!areArrays) {if (typeof a != 'object' || typeof b != 'object') return false;// Objects with different constructors are not equivalent, but `Object`s or `Array`s// from different frames are.var aCtor = a.constructor, bCtor = b.constructor;if (aCtor !== bCtor && !(_.isFunction(aCtor) && aCtor instanceof aCtor &&_.isFunction(bCtor) && bCtor instanceof bCtor)&& ('constructor' in a && 'constructor' in b)) {return false;}}// Assume equality for cyclic structures. The algorithm for detecting cyclic// structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.// Initializing stack of traversed objects.// It's done here since we only need them for objects and arrays comparison.aStack = aStack || [];bStack = bStack || [];var length = aStack.length;while (length--) {// Linear search. Performance is inversely proportional to the number of// unique nested structures.if (aStack[length] === a) return bStack[length] === b;}// Add the first object to the stack of traversed objects.aStack.push(a);bStack.push(b);// Recursively compare objects and arrays.if (areArrays) {// Compare array lengths to determine if a deep comparison is necessary.length = a.length;if (length !== b.length) return false;// Deep compare the contents, ignoring non-numeric properties.while (length--) {if (!eq(a[length], b[length], aStack, bStack)) return false;}} else {// Deep compare objects.var keys = _.keys(a), key;length = keys.length;// Ensure that both objects contain the same number of properties before comparing deep equality.if (_.keys(b).length !== length) return false;while (length--) {// Deep compare each memberkey = keys[length];if (!(_.has(b, key) && eq(a[key], b[key], aStack, bStack))) return false;}}// Remove the first object from the stack of traversed objects.aStack.pop();bStack.pop();return true;};// Perform a deep comparison to check if two objects are equal._.isEqual = function(a, b) {return eq(a, b);};// Is a given array, string, or object empty?// An "empty" object has no enumerable own-properties._.isEmpty = function(obj) {if (obj == null) return true;if (isArrayLike(obj) && (_.isArray(obj) || _.isString(obj) || _.isArguments(obj))) return obj.length === 0;return _.keys(obj).length === 0;};// Is a given value a DOM element?_.isElement = function(obj) {return !!(obj && obj.nodeType === 1);};// Is a given value an array?// Delegates to ECMA5's native Array.isArray_.isArray = nativeIsArray || function(obj) {return toString.call(obj) === '[object Array]';};// Is a given variable an object?_.isObject = function(obj) {var type = typeof obj;return type === 'function' || type === 'object' && !!obj;};// Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp, isError._.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp', 'Error'], function(name) {_['is' + name] = function(obj) {return toString.call(obj) === '[object ' + name + ']';};});// Define a fallback version of the method in browsers (ahem, IE < 9), where// there isn't any inspectable "Arguments" type.if (!_.isArguments(arguments)) {_.isArguments = function(obj) {return _.has(obj, 'callee');};}// Optimize `isFunction` if appropriate. Work around some typeof bugs in old v8,// IE 11 (#1621), and in Safari 8 (#1929).if (typeof /./ != 'function' && typeof Int8Array != 'object') {_.isFunction = function(obj) {return typeof obj == 'function' || false;};}// Is a given object a finite number?_.isFinite = function(obj) {return isFinite(obj) && !isNaN(parseFloat(obj));};// Is the given value `NaN`? (NaN is the only number which does not equal itself)._.isNaN = function(obj) {return _.isNumber(obj) && obj !== +obj;};// Is a given value a boolean?_.isBoolean = function(obj) {return obj === true || obj === false || toString.call(obj) === '[object Boolean]';};// Is a given value equal to null?_.isNull = function(obj) {return obj === null;};// Is a given variable undefined?_.isUndefined = function(obj) {return obj === void 0;};// Shortcut function for checking if an object has a given property directly// on itself (in other words, not on a prototype)._.has = function(obj, key) {return obj != null && hasOwnProperty.call(obj, key);};// Utility Functions// -----------------// Run Underscore.js in *noConflict* mode, returning the `_` variable to its// previous owner. Returns a reference to the Underscore object._.noConflict = function() {root._ = previousUnderscore;return this;};// Keep the identity function around for default iteratees._.identity = function(value) {return value;};// Predicate-generating functions. Often useful outside of Underscore._.constant = function(value) {return function() {return value;};};_.noop = function(){};_.property = property;// Generates a function for a given object that returns a given property._.propertyOf = function(obj) {return obj == null ? function(){} : function(key) {return obj[key];};};// Returns a predicate for checking whether an object has a given set of// `key:value` pairs._.matcher = _.matches = function(attrs) {attrs = _.extendOwn({}, attrs);return function(obj) {return _.isMatch(obj, attrs);};};// Run a function **n** times._.times = function(n, iteratee, context) {var accum = Array(Math.max(0, n));iteratee = optimizeCb(iteratee, context, 1);for (var i = 0; i < n; i++) accum[i] = iteratee(i);return accum;};// Return a random integer between min and max (inclusive)._.random = function(min, max) {if (max == null) {max = min;min = 0;}return min + Math.floor(Math.random() * (max - min + 1));};// A (possibly faster) way to get the current timestamp as an integer._.now = Date.now || function() {return new Date().getTime();};// List of HTML entities for escaping.var escapeMap = {'&': '&','<': '<','>': '>','"': '"',"'": ''','`': '`'};var unescapeMap = _.invert(escapeMap);// Functions for escaping and unescaping strings to/from HTML interpolation.var createEscaper = function(map) {var escaper = function(match) {return map[match];};// Regexes for identifying a key that needs to be escapedvar source = '(?:' + _.keys(map).join('|') + ')';var testRegexp = RegExp(source);var replaceRegexp = RegExp(source, 'g');return function(string) {string = string == null ? '' : '' + string;return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string;};};_.escape = createEscaper(escapeMap);_.unescape = createEscaper(unescapeMap);// If the value of the named `property` is a function then invoke it with the// `object` as context; otherwise, return it._.result = function(object, property, fallback) {var value = object == null ? void 0 : object[property];if (value === void 0) {value = fallback;}return _.isFunction(value) ? value.call(object) : value;};// Generate a unique integer id (unique within the entire client session).// Useful for temporary DOM ids.var idCounter = 0;_.uniqueId = function(prefix) {var id = ++idCounter + '';return prefix ? prefix + id : id;};// By default, Underscore uses ERB-style template delimiters, change the// following template settings to use alternative delimiters._.templateSettings = {evaluate : /<%([\s\S]+?)%>/g,interpolate : /<%=([\s\S]+?)%>/g,escape : /<%-([\s\S]+?)%>/g};// When customizing `templateSettings`, if you don't want to define an// interpolation, evaluation or escaping regex, we need one that is// guaranteed not to match.var noMatch = /(.)^/;// Certain characters need to be escaped so that they can be put into a// string literal.var escapes = {"'": "'",'\\': '\\','\r': 'r','\n': 'n','\u2028': 'u2028','\u2029': 'u2029'};var escaper = /\\|'|\r|\n|\u2028|\u2029/g;var escapeChar = function(match) {return '\\' + escapes[match];};// JavaScript micro-templating, similar to John Resig's implementation.// Underscore templating handles arbitrary delimiters, preserves whitespace,// and correctly escapes quotes within interpolated code.// NB: `oldSettings` only exists for backwards compatibility._.template = function(text, settings, oldSettings) {if (!settings && oldSettings) settings = oldSettings;settings = _.defaults({}, settings, _.templateSettings);// Combine delimiters into one regular expression via alternation.var matcher = RegExp([(settings.escape || noMatch).source,(settings.interpolate || noMatch).source,(settings.evaluate || noMatch).source].join('|') + '|$', 'g');// Compile the template source, escaping string literals appropriately.var index = 0;var source = "__p+='";text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {source += text.slice(index, offset).replace(escaper, escapeChar);index = offset + match.length;if (escape) {source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";} else if (interpolate) {source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";} else if (evaluate) {source += "';\n" + evaluate + "\n__p+='";}// Adobe VMs need the match returned to produce the correct offest.return match;});source += "';\n";// If a variable is not specified, place data values in local scope.if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';source = "var __t,__p='',__j=Array.prototype.join," +"print=function(){__p+=__j.call(arguments,'');};\n" +source + 'return __p;\n';try {var render = new Function(settings.variable || 'obj', '_', source);} catch (e) {e.source = source;throw e;}var template = function(data) {return render.call(this, data, _);};// Provide the compiled source as a convenience for precompilation.var argument = settings.variable || 'obj';template.source = 'function(' + argument + '){\n' + source + '}';return template;};// Add a "chain" function. Start chaining a wrapped Underscore object._.chain = function(obj) {var instance = _(obj);instance._chain = true;return instance;};// OOP// ---------------// If Underscore is called as a function, it returns a wrapped object that// can be used OO-style. This wrapper holds altered versions of all the// underscore functions. Wrapped objects may be chained.// Helper function to continue chaining intermediate results.var result = function(instance, obj) {return instance._chain ? _(obj).chain() : obj;};// Add your own custom functions to the Underscore object._.mixin = function(obj) {_.each(_.functions(obj), function(name) {var func = _[name] = obj[name];_.prototype[name] = function() {var args = [this._wrapped];push.apply(args, arguments);return result(this, func.apply(_, args));};});};// Add all of the Underscore functions to the wrapper object._.mixin(_);// Add all mutator Array functions to the wrapper._.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {var method = ArrayProto[name];_.prototype[name] = function() {var obj = this._wrapped;method.apply(obj, arguments);if ((name === 'shift' || name === 'splice') && obj.length === 0) delete obj[0];return result(this, obj);};});// Add all accessor Array functions to the wrapper._.each(['concat', 'join', 'slice'], function(name) {var method = ArrayProto[name];_.prototype[name] = function() {return result(this, method.apply(this._wrapped, arguments));};});// Extracts the result from a wrapped and chained object._.prototype.value = function() {return this._wrapped;};// Provide unwrapping proxy for some methods used in engine operations// such as arithmetic and JSON stringification._.prototype.valueOf = _.prototype.toJSON = _.prototype.value;_.prototype.toString = function() {return '' + this._wrapped;};// AMD registration happens at the end for compatibility with AMD loaders// that may not enforce next-turn semantics on modules. Even though general// practice for AMD registration is to be anonymous, underscore registers// as a named module because, like jQuery, it is a base library that is// popular enough to be bundled in a third party lib, but not be part of// an AMD load request. Those cases could generate an error when an// anonymous define() is called outside of a loader request.if (typeof define === 'function' && define.amd) {define('underscore', [], function() {return _;});} }.call(this));

2.簡(jiǎn)單實(shí)例

<!DOCTYPE html> <html lang="en"> <head><meta charset="UTF-8"><title>Document</title><script type="underscore.js"></script> </head> <body><!--折疊面板maccordion--><div class="mui-card"><ul class="mui-table-view" id="factoryLists"></ul></div><!-- 列表 --> <script type="text/template" id="tpl"> <% for(var i = 0; i < data.length; i++) { %> <% var item = data[i] %><li class="mui-table-view-cell mui-collapse-3"><a class="mui-navigate-right" href="#"><%=item.name%></a><ul class="mui-table-view"><% for(var j = 0; j < item.floorList.length; j++) { %> <% var single = item.floorList[j] %><% if(single.modelScene == "suidaoSelect") { %><li class="mui-table-view-cell mui-collapse-3"><a class="mui-navigate-right" href="#"><%=single.floorName%></a><ul class="mui-table-view"><li class="mui-table-view-cell"><div class="mui-collapse-content"><% for(var k = 0; k < single.subFloor.length; k++) { %> <% var odd = single.subFloor[k] %><div class="mui-input-row change_view" modelScene="<%=single.modelScene%>" floorId="<%=odd.id%>" beginMile="<%=odd.beginMile%>" lengthMile="<%=odd.lengthMile%>" name="<%=odd.name%>"><%=odd.name%></div><% } %></div></li></ul></li><% }else{ %><li class="mui-table-view-cell mui-collapse-3"><a class="change_view" modelScene="<%=single.modelScene%>" floorId="<%=single.floorId%>" href="#"><%=single.floorName%></a></li><% } %><% } %></ul></li><% } %></script><script>// 獲取渲染元素和模板內(nèi)容 var factoryLists = $('#factoryLists');var tpl = $('#tpl').html();$.ajax({url: apiUrl.factoryList,type:'POST',data: JSON.stringify(params),dataType : 'json',contentType : 'application/json',success:function(data){debug && console.log(JSON.stringify(data));// 解析模板, 返回解析后的內(nèi)容 var render = _.template(tpl); var html = render(data); // 將解析后的內(nèi)容填充到渲染元素 factoryLists.html(html);}});</script> </body> </html>

3.效果圖

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總結(jié)

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