#

API Docs for: 3.10.3
Show: Inherited Protected Private Deprecated

# File: oop/js/oop.js

    /**
    Adds object inheritance and manipulation utilities to the YUI instance. This
    module is required by most YUI components.

    @module oop
    **/

    var L            = Y.Lang,
        A            = Y.Array,
        OP           = Object.prototype,
        CLONE_MARKER = '_~yuim~_',

        hasOwn   = OP.hasOwnProperty,
        toString = OP.toString;

    function dispatch(o, f, c, proto, action) {
        if (o && o[action] && o !== Y) {
            return o[action].call(o, f, c);
        } else {
            switch (A.test(o)) {
                case 1:
                    return A[action](o, f, c);
                case 2:
                    return A[action](Y.Array(o, 0, true), f, c);
                default:
                    return Y.Object[action](o, f, c, proto);
            }
        }
    }

    /**
    Augments the _receiver_ with prototype properties from the _supplier_. The
    receiver may be a constructor function or an object. The supplier must be a
    constructor function.

    If the _receiver_ is an object, then the _supplier_ constructor will be called
    immediately after _receiver_ is augmented, with _receiver_ as the `this` object.

    If the _receiver_ is a constructor function, then all prototype methods of
    _supplier_ that are copied to _receiver_ will be sequestered, and the
    _supplier_ constructor will not be called immediately. The first time any
    sequestered method is called on the _receiver_'s prototype, all sequestered
    methods will be immediately copied to the _receiver_'s prototype, the
    _supplier_'s constructor will be executed, and finally the newly unsequestered
    method that was called will be executed.

    This sequestering logic sounds like a bunch of complicated voodoo, but it makes
    it cheap to perform frequent augmentation by ensuring that suppliers'
    constructors are only called if a supplied method is actually used. If none of
    the supplied methods is ever used, then there's no need to take the performance
    hit of calling the _supplier_'s constructor.

    @method augment
    @param {Function|Object} receiver Object or function to be augmented.
    @param {Function} supplier Function that supplies the prototype properties with
      which to augment the _receiver_.
    @param {Boolean} [overwrite=false] If `true`, properties already on the receiver
      will be overwritten if found on the supplier's prototype.
    @param {String[]} [whitelist] An array of property names. If specified,
      only the whitelisted prototype properties will be applied to the receiver, and
      all others will be ignored.
    @param {Array|any} [args] Argument or array of arguments to pass to the
      supplier's constructor when initializing.
    @return {Function} Augmented object.
    @for YUI
    **/
    Y.augment = function (receiver, supplier, overwrite, whitelist, args) {
        var rProto    = receiver.prototype,
            sequester = rProto && supplier,
            sProto    = supplier.prototype,
            to        = rProto || receiver,

            copy,
            newPrototype,
            replacements,
            sequestered,
            unsequester;

        args = args ? Y.Array(args) : [];

        if (sequester) {
            newPrototype = {};
            replacements = {};
            sequestered  = {};

            copy = function (value, key) {
                if (overwrite || !(key in rProto)) {
                    if (toString.call(value) === '[object Function]') {
                        sequestered[key] = value;

                        newPrototype[key] = replacements[key] = function () {
                            return unsequester(this, value, arguments);
                        };
                    } else {
                        newPrototype[key] = value;
                    }
                }
            };

            unsequester = function (instance, fn, fnArgs) {
                // Unsequester all sequestered functions.
                for (var key in sequestered) {
                    if (hasOwn.call(sequestered, key)
                            && instance[key] === replacements[key]) {

                        instance[key] = sequestered[key];
                    }
                }

                // Execute the supplier constructor.
                supplier.apply(instance, args);

                // Finally, execute the original sequestered function.
                return fn.apply(instance, fnArgs);
            };

            if (whitelist) {
                Y.Array.each(whitelist, function (name) {
                    if (name in sProto) {
                        copy(sProto[name], name);
                    }
                });
            } else {
                Y.Object.each(sProto, copy, null, true);
            }
        }

        Y.mix(to, newPrototype || sProto, overwrite, whitelist);

        if (!sequester) {
            supplier.apply(to, args);
        }

        return receiver;
    };

    /**
     * Copies object properties from the supplier to the receiver. If the target has
     * the property, and the property is an object, the target object will be
     * augmented with the supplier's value.
     *
     * @method aggregate
     * @param {Object} receiver Object to receive the augmentation.
     * @param {Object} supplier Object that supplies the properties with which to
     *     augment the receiver.
     * @param {Boolean} [overwrite=false] If `true`, properties already on the receiver
     *     will be overwritten if found on the supplier.
     * @param {String[]} [whitelist] Whitelist. If supplied, only properties in this
     *     list will be applied to the receiver.
     * @return {Object} Augmented object.
     */
    Y.aggregate = function(r, s, ov, wl) {
        return Y.mix(r, s, ov, wl, 0, true);
    };

    /**
     * Utility to set up the prototype, constructor and superclass properties to
     * support an inheritance strategy that can chain constructors and methods.
     * Static members will not be inherited.
     *
     * @method extend
     * @param {function} r   the object to modify.
     * @param {function} s the object to inherit.
     * @param {object} px prototype properties to add/override.
     * @param {object} sx static properties to add/override.
     * @return {object} the extended object.
     */
    Y.extend = function(r, s, px, sx) {
        if (!s || !r) {
            Y.error('extend failed, verify dependencies');
        }

        var sp = s.prototype, rp = Y.Object(sp);
        r.prototype = rp;

        rp.constructor = r;
        r.superclass = sp;

        // assign constructor property
        if (s != Object && sp.constructor == OP.constructor) {
            sp.constructor = s;
        }

        // add prototype overrides
        if (px) {
            Y.mix(rp, px, true);
        }

        // add object overrides
        if (sx) {
            Y.mix(r, sx, true);
        }

        return r;
    };

    /**
     * Executes the supplied function for each item in
     * a collection.  Supports arrays, objects, and
     * NodeLists
     * @method each
     * @param {object} o the object to iterate.
     * @param {function} f the function to execute.  This function
     * receives the value, key, and object as parameters.
     * @param {object} c the execution context for the function.
     * @param {boolean} proto if true, prototype properties are
     * iterated on objects.
     * @return {YUI} the YUI instance.
     */
    Y.each = function(o, f, c, proto) {
        return dispatch(o, f, c, proto, 'each');
    };

    /**
     * Executes the supplied function for each item in
     * a collection.  The operation stops if the function
     * returns true. Supports arrays, objects, and
     * NodeLists.
     * @method some
     * @param {object} o the object to iterate.
     * @param {function} f the function to execute.  This function
     * receives the value, key, and object as parameters.
     * @param {object} c the execution context for the function.
     * @param {boolean} proto if true, prototype properties are
     * iterated on objects.
     * @return {boolean} true if the function ever returns true,
     * false otherwise.
     */
    Y.some = function(o, f, c, proto) {
        return dispatch(o, f, c, proto, 'some');
    };

    /**
    Deep object/array copy. Function clones are actually wrappers around the
    original function. Array-like objects are treated as arrays. Primitives are
    returned untouched. Optionally, a function can be provided to handle other data
    types, filter keys, validate values, etc.

    **Note:** Cloning a non-trivial object is a reasonably heavy operation, due to
    the need to recursively iterate down non-primitive properties. Clone should be
    used only when a deep clone down to leaf level properties is explicitly
    required. This method will also

    In many cases (for example, when trying to isolate objects used as hashes for
    configuration properties), a shallow copy, using `Y.merge()` is normally
    sufficient. If more than one level of isolation is required, `Y.merge()` can be
    used selectively at each level which needs to be isolated from the original
    without going all the way to leaf properties.

    @method clone
    @param {object} o what to clone.
    @param {boolean} safe if true, objects will not have prototype items from the
        source. If false, they will. In this case, the original is initially
        protected, but the clone is not completely immune from changes to the source
        object prototype. Also, cloned prototype items that are deleted from the
        clone will result in the value of the source prototype being exposed. If
        operating on a non-safe clone, items should be nulled out rather than
        deleted.
    @param {function} f optional function to apply to each item in a collection; it
        will be executed prior to applying the value to the new object.
        Return false to prevent the copy.
    @param {object} c optional execution context for f.
    @param {object} owner Owner object passed when clone is iterating an object.
        Used to set up context for cloned functions.
    @param {object} cloned hash of previously cloned objects to avoid multiple
        clones.
    @return {Array|Object} the cloned object.
    **/
    Y.clone = function(o, safe, f, c, owner, cloned) {
        var o2, marked, stamp;

        // Does not attempt to clone:
        //
        // * Non-typeof-object values, "primitive" values don't need cloning.
        //
        // * YUI instances, cloning complex object like YUI instances is not
        //   advised, this is like cloning the world.
        //
        // * DOM nodes (#2528250), common host objects like DOM nodes cannot be
        //   "subclassed" in Firefox and old versions of IE. Trying to use
        //   `Object.create()` or `Y.extend()` on a DOM node will throw an error in
        //   these browsers.
        //
        // Instad, the passed-in `o` will be return as-is when it matches one of the
        // above criteria.
        if (!L.isObject(o) ||
                Y.instanceOf(o, YUI) ||
                (o.addEventListener || o.attachEvent)) {

            return o;
        }

        marked = cloned || {};

        switch (L.type(o)) {
            case 'date':
                return new Date(o);
            case 'regexp':
                // if we do this we need to set the flags too
                // return new RegExp(o.source);
                return o;
            case 'function':
                // o2 = Y.bind(o, owner);
                // break;
                return o;
            case 'array':
                o2 = [];
                break;
            default:

                // #2528250 only one clone of a given object should be created.
                if (o[CLONE_MARKER]) {
                    return marked[o[CLONE_MARKER]];
                }

                stamp = Y.guid();

                o2 = (safe) ? {} : Y.Object(o);

                o[CLONE_MARKER] = stamp;
                marked[stamp] = o;
        }

        Y.each(o, function(v, k) {
            if ((k || k === 0) && (!f || (f.call(c || this, v, k, this, o) !== false))) {
                if (k !== CLONE_MARKER) {
                    if (k == 'prototype') {
                        // skip the prototype
                    // } else if (o[k] === o) {
                    //     this[k] = this;
                    } else {
                        this[k] =
                            Y.clone(v, safe, f, c, owner || o, marked);
                    }
                }
            }
        }, o2);

        if (!cloned) {
            Y.Object.each(marked, function(v, k) {
                if (v[CLONE_MARKER]) {
                    try {
                        delete v[CLONE_MARKER];
                    } catch (e) {
                        v[CLONE_MARKER] = null;
                    }
                }
            }, this);
            marked = null;
        }

        return o2;
    };

    /**
     * Returns a function that will execute the supplied function in the
     * supplied object's context, optionally adding any additional
     * supplied parameters to the beginning of the arguments collection the
     * supplied to the function.
     *
     * @method bind
     * @param {Function|String} f the function to bind, or a function name
     * to execute on the context object.
     * @param {object} c the execution context.
     * @param {any} args* 0..n arguments to include before the arguments the
     * function is executed with.
     * @return {function} the wrapped function.
     */
    Y.bind = function(f, c) {
        var xargs = arguments.length > 2 ?
                Y.Array(arguments, 2, true) : null;
        return function() {
            var fn = L.isString(f) ? c[f] : f,
                args = (xargs) ?
                    xargs.concat(Y.Array(arguments, 0, true)) : arguments;
            return fn.apply(c || fn, args);
        };
    };

    /**
     * Returns a function that will execute the supplied function in the
     * supplied object's context, optionally adding any additional
     * supplied parameters to the end of the arguments the function
     * is executed with.
     *
     * @method rbind
     * @param {Function|String} f the function to bind, or a function name
     * to execute on the context object.
     * @param {object} c the execution context.
     * @param {any} args* 0..n arguments to append to the end of
     * arguments collection supplied to the function.
     * @return {function} the wrapped function.
     */
    Y.rbind = function(f, c) {
        var xargs = arguments.length > 2 ? Y.Array(arguments, 2, true) : null;
        return function() {
            var fn = L.isString(f) ? c[f] : f,
                args = (xargs) ?
                    Y.Array(arguments, 0, true).concat(xargs) : arguments;
            return fn.apply(c || fn, args);
        };
    };