/** * Bootstrap.js JavaScript Inheritance Microframework * Copyright (c) 2006 - 2013 Juerg Lehni * http://lehni.org/ * * Distributed under the MIT license. * * Inspirations: * http://dean.edwards.name/weblog/2006/03/base/ * http://dev.helma.org/Wiki/JavaScript+Inheritance+Sugar/ * http://prototypejs.org/ */ var Base = new function() { // Bootstrap scope var hidden = /^(statics|generics|preserve|enumerable|prototype|toString|valueOf)$/, proto = Object.prototype, toString = proto.toString, proto = Array.prototype, isArray = Array.isArray = Array.isArray || function(obj) { return toString.call(obj) === '[object Array]'; }, slice = proto.slice, forEach = proto.forEach || function(iter, bind) { for (var i = 0, l = this.length; i < l; i++) iter.call(bind, this[i], i, this); }, forIn = function(iter, bind) { // Do not use Object.keys for iteration as iterators might modify // the object we're iterating over, making the hasOwnProperty still // necessary. for (var i in this) if (this.hasOwnProperty(i)) iter.call(bind, this[i], i, this); }, // A ahort cut to a simplified version of Object.create that only // supports the first parameter (in the emulation): create = Object.create || function(proto) { // From all browsers that do not offer Object.create(), we only // support Firefox 3.5 & 3.5, but luckily this hack works there: return { __proto__: proto }; }, _define = Object.defineProperty, _describe = Object.getOwnPropertyDescriptor; // Support a mixed environment of some ECMAScript 5 features present, // along with __defineGetter/Setter__ functions, as found in browsers today. function define(obj, name, desc) { // Unfortunately Safari seems to ignore configurable: true and // does not override existing properties, so we need to delete // first: if (_define) { try { delete obj[name]; return _define(obj, name, desc); } catch (e) {} } if ((desc.get || desc.set) && obj.__defineGetter__) { desc.get && obj.__defineGetter__(name, desc.get); desc.set && obj.__defineSetter__(name, desc.set); } else { obj[name] = desc.value; } return obj; } function describe(obj, name) { if (_describe) { try { return _describe(obj, name); } catch (e) {} } var get = obj.__lookupGetter__ && obj.__lookupGetter__(name); return get ? { get: get, set: obj.__lookupSetter__(name), enumerable: true, configurable: true } : obj.hasOwnProperty(name) ? { value: obj[name], enumerable: true, configurable: true, writable: true } : null; } /** * Private function that injects functions from src into dest, overriding * (and inherinting from) base. */ function inject(dest, src, enumerable, base, preserve, generics) { var beans, bean; /** * Private function that injects one field with given name and checks if * the field is a function that needs to be wrapped for calls of base(). * This is only needed if the function in base is different from the one * in src, and if the one in src is actually calling base through base. * The string of the function is parsed for this.base to detect calls. */ function field(name, val, dontCheck, generics) { // This does even work for prop: 0, as it will just be looked up // again through describe. var val = val || (val = describe(src, name)) && (val.get ? val : val.value), func = typeof val === 'function', res = val, // Only lookup previous value if we preserve or define a // function that might need it for this.base(). If we're // defining a getter, don't lookup previous value, but look if // the property exists (name in dest) and store result in prev prev = preserve || func ? (val && val.get ? name in dest : dest[name]) : null; if ((dontCheck || val !== undefined && src.hasOwnProperty(name)) && (!preserve || !prev)) { if (func) { if (prev && /\bthis\.base\b/.test(val)) { var fromBase = base && base[name] == prev; res = function() { // Look up the base function each time if we can, // to reflect changes to the base class after // inheritance. var tmp = describe(this, 'base'); define(this, 'base', { value: fromBase ? base[name] : prev, configurable: true }); try { return val.apply(this, arguments); } finally { tmp ? define(this, 'base', tmp) : delete this.base; } }; // Make wrapping closure pretend to be the original // function on inspection res.toString = function() { return val.toString(); }; res.valueOf = function() { return val.valueOf(); }; } // Produce bean properties if getters are specified. This // does not produce properties for setter-only properties. // Just collect beans for now, and look them up in dest at // the end of fields injection. This ensures this.base() // works in beans too, and inherits setters for redefined // getters in subclasses. Only add getter beans if they do // not expect arguments. Functions that should function both // with optional arguments and as beans should not declare // the parameters and use the arguments array internally // instead. if (beans && val.length === 0 && (bean = name.match(/^(get|is)(([A-Z])(.*))$/))) beans.push([ bean[3].toLowerCase() + bean[4], bean[2] ]); } // No need to look up getter if this is a function already. if (!res || func || !res.get) res = { value: res, writable: true }; // Only set/change configurable and enumerable if this field is // configurable if ((describe(dest, name) || { configurable: true }).configurable) { res.configurable = true; res.enumerable = enumerable; } define(dest, name, res); } if (generics && func && (!preserve || !generics[name])) { generics[name] = function(bind) { // Do not call Array.slice generic here, as on Safari, // this seems to confuse scopes (calling another // generic from generic-producing code). return bind && dest[name].apply(bind, slice.call(arguments, 1)); }; } } // Iterate through all definitions in src now and call field() for each. if (src) { beans = []; for (var name in src) if (src.hasOwnProperty(name) && !hidden.test(name)) field(name, null, true, generics); // IE (and some other browsers?) never enumerate these, even if // they are simply set on an object. Force their creation. Do not // create generics for these, and check them for not being defined // (by passing undefined for dontCheck). field('toString'); field('valueOf'); // Now finally define beans as well. Look up methods on dest, for // support of this.base() (See above). for (var i = 0, l = beans && beans.length; i < l; i++) try { var bean = beans[i], part = bean[1]; field(bean[0], { get: dest['get' + part] || dest['is' + part], set: dest['set' + part] }, true); } catch (e) {} } return dest; } function each(obj, iter, bind, asArray) { try { if (obj) (asArray || asArray === undefined && isArray(obj) ? forEach : forIn).call(obj, iter, bind = bind || obj); } catch (e) { if (e !== Base.stop) throw e; } return bind; } function clone(obj) { return each(obj, function(val, i) { this[i] = val; }, new obj.constructor()); } // Inject into new ctor object that's passed to inject(), and then returned return inject(function() {}, { inject: function(src/*, ... */) { if (src) { var proto = this.prototype, base = Object.getPrototypeOf(proto).constructor, // Allow the whole scope to just define statics by defining // statics: true. statics = src.statics === true ? src : src.statics; if (statics != src) inject(proto, src, src.enumerable, base && base.prototype, src.preserve, src.generics && this); // Define new static fields as enumerable, and inherit from // base. enumerable is necessary so they can be copied over from // base, and it does not harm to have enumerable properties in // the constructor. Use the preserve setting in src.preserve for // statics too, not their own. inject(this, statics, true, base, src.preserve); } // If there are more than one argument, loop through them and call // inject again. Do not simple inline the above code in one loop, // since each of the passed objects might override this.inject. for (var i = 1, l = arguments.length; i < l; i++) this.inject(arguments[i]); return this; }, extend: function(src/* , ... */) { var ctor = function() { // Call the constructor function, if defined if (this.initialize) return this.initialize.apply(this, arguments); }; ctor.prototype = create(this.prototype); // Add a toString function that delegates to initialize if possible ctor.toString = function() { return (this.prototype.initialize || function() {}).toString(); }; // The new prototype extends the constructor on which extend is // called. Fix constructor. define(ctor.prototype, 'constructor', { value: ctor, writable: true, configurable: true }); // Copy over static fields, as prototype-like inheritance // is not possible for static fields. Mark them as enumerable // so they can be copied over again. inject(ctor, this, true); // Inject all the definitions in src. Use the new inject instead of // the one in ctor, in case it was overriden. this is needed when // overriding the static .inject(). But only inject if there's // something to actually inject. return arguments.length ? this.inject.apply(ctor, arguments) : ctor; } // Pass true for enumerable, so inject() and extend() can be passed on // to subclasses of Base through Base.inject() / extend(). }, true).inject({ /** * Injects the fields from the given object, adding this.base() * functionality */ inject: function(/* src, ... */) { for (var i = 0, l = arguments.length; i < l; i++) inject(this, arguments[i], arguments[i].enumerable); return this; }, /** * Returns a new object that inherits all properties from "this", * through proper JS inheritance, not copying. * Optionally, src and hide parameters can be passed to fill in the * newly created object just like in inject(), to copy the behavior * of Function.prototype.extend. */ extend: function(/* src, ... */) { var res = create(this); return res.inject.apply(res, arguments); }, each: function(iter, bind) { return each(this, iter, bind); }, /** * Creates a new object of the same type and copies over all * name / value pairs from this object. */ clone: function() { return clone(this); }, statics: { // Expose some local privates as Base generics. each: each, clone: clone, define: define, describe: describe, // Base.create does something different from Object.create, it only // works on constructors and uses their prototype. create: function(ctor) { return create(ctor.prototype); }, /** * Returns true if obj is a plain JavaScript object literal, or a * plain Base object, as produced by Base.merge(). */ isPlainObject: function(obj) { var proto = obj !== null && typeof obj === 'object' && Object.getPrototypeOf(obj); return proto && (proto === Object.prototype || proto === Base.prototype); }, check: function(obj) { return !!(obj || obj === 0); }, /** * Returns the first argument that is defined. * Null is counted as defined too, since !== undefined is used for * comparisons. In this it differs from Mootools! */ pick: function() { for (var i = 0, l = arguments.length; i < l; i++) if (arguments[i] !== undefined) return arguments[i]; return null; }, /** * A special constant, to be thrown by closures passed to each() * * $continue / Base.next is not implemented, as the same * functionality can achieved by using return in the closure. * In prototype, the implementation of $continue also leads to a * huge speed decrease, as the closure is wrapped in another closure * that does nothing else than handling $continue. */ stop: {} } }); };