API Docs for: 0.7.5
Show:

File: node_modules/mojito/lib/app/autoload/model-vanilla.common.js

/*
 * Copyright (c) 2011-2013, Yahoo! Inc.  All rights reserved.
 * Copyrights licensed under the New BSD License.
 * See the accompanying LICENSE file for terms.
 */

/*jslint anon:true, sloppy:true, nomen:true */
/*global YUI*/

YUI.add('model-vanilla', function (Y, NAME) {

    'use strict';

    /**
    TODO: This will eventually become part of the YUI Core, (work in progress here
    https://github.com/yui/yui3/pull/323), and the only pending work in mojito will
    be to remove this file, and replace apidoc references to Model.Vanilla with
    Y.Model.

    @module app
    @submodule model-vanilla
    @since 3.11.0
    **/

    var GlobalEnv = YUI.namespace('Env.Model'),

        AttributeCore   = Y.AttributeCore,
        AttributeExtras = Y.AttributeExtras,
        Lang            = Y.Lang,
        YArray          = Y.Array,
        YObject         = Y.Object;

    /**
    Attribute-based data model with APIs for getting, setting, validating, and
    syncing attribute values.

    This Vanilla model does NOT use `Y.BaseCore`, instead it uses `Y.mix()` and
    a regular prototype definition to mix in the model api with the AttributeCore
    and AttributeExtras to provide the exact same API that `Y.Model` exposes but
    with better performance when it comes to the server runtime.

    See also http://yuilibrary.com/yui/docs/api/classes/Model.html

    @class Model.Vanilla
    @constructor
    **/
    function ModelVanilla(config) {
        this.changed    = {};
        this.lastChange = {};
        this.lists      = [];
        this.idAttribute = 'id';
        this._allowAdHocAttrs = true;
        this._isYUIModel = true;
        AttributeCore.apply(this, arguments);
        AttributeExtras.apply(this, arguments);
        if (config) {
            this.setAttrs(config);
        }
    }
    ModelVanilla.prototype = {
        // -- Public Properties ----------------------------------------------------

        /**
        Hash of attributes that have changed since the last time this model was
        saved.

        @property changed
        @type Object
        @default {}
        **/

        /**
        Name of the attribute to use as the unique id (or primary key) for this
        model.

        The default is `id`, but if your persistence layer uses a different name for
        the primary key (such as `_id` or `uid`), you can specify that here.

        The built-in `id` attribute will always be an alias for whatever attribute
        name you specify here, so getting and setting `id` will always behave the
        same as getting and setting your custom id attribute.

        @property idAttribute
        @type String
        @default `'id'`
        **/
        // idAttribute: 'id',

        /**
        Hash of attributes that were changed in the last `change` event. Each item
        in this hash is an object with the following properties:

          * `newVal`: The new value of the attribute after it changed.
          * `prevVal`: The old value of the attribute before it changed.
          * `src`: The source of the change, or `null` if no source was specified.

        @property lastChange
        @type Object
        @default {}
        **/

        /**
        Array of `ModelList` instances that contain this model.

        When a model is in one or more lists, the model's events will bubble up to
        those lists. You can subscribe to a model event on a list to be notified
        when any model in the list fires that event.

        This property is updated automatically when this model is added to or
        removed from a `ModelList` instance. You shouldn't alter it manually. When
        working with models in a list, you should always add and remove models using
        the list's `add()` and `remove()` methods.

        @example Subscribing to model events on a list:

            // Assuming `list` is an existing Y.ModelList instance.
            list.on('*:change', function (e) {
                // This function will be called whenever any model in the list
                // fires a `change` event.
                //
                // `e.target` will refer to the model instance that fired the
                // event.
            });

        @property lists
        @type ModelList[]
        @default `[]`
        **/

        // -- Protected Properties -------------------------------------------------

        /**
        This tells `Y.Base` that it should create ad-hoc attributes for config
        properties passed to Model's constructor. This makes it possible to
        instantiate a model and set a bunch of attributes without having to subclass
        `Y.Model` and declare all those attributes first.

        @property _allowAdHocAttrs
        @type Boolean
        @default true
        @protected
        @since 3.5.0
        **/
        // _allowAdHocAttrs: true,

        /**
        Total hack to allow us to identify Model instances without using
        `instanceof`, which won't work when the instance was created in another
        window or YUI sandbox.

        @property _isYUIModel
        @type Boolean
        @default true
        @protected
        @since 3.5.0
        **/
        // _isYUIModel: true,

        // -- Public Methods -------------------------------------------------------

        /**
        Returns a clientId string that's unique among all models on the current page
        (even models in other YUI instances). Uniqueness across pageviews is
        unlikely.

        @method generateClientId
        @return {String} Unique clientId.
        **/
        generateClientId: function () {
            GlobalEnv.lastId = GlobalEnv.lastId || 0;
            return this.constructor.NAME + '_' + (GlobalEnv.lastId += 1);
        },

        /**
        Returns the value of the specified attribute.

        If the attribute's value is an object, _name_ may use dot notation to
        specify the path to a specific property within the object, and the value of
        that property will be returned.

        @example
            // Set the 'foo' attribute to an object.
            myModel.set('foo', {
                bar: {
                    baz: 'quux'
                }
            });

            // Get the value of 'foo'.
            myModel.get('foo');
            // => {bar: {baz: 'quux'}}

            // Get the value of 'foo.bar.baz'.
            myModel.get('foo.bar.baz');
            // => 'quux'

        @method get
        @param {String} name Attribute name or object property path.
        @return {Any} Attribute value, or `undefined` if the attribute doesn't
          exist.
        **/

        // get() is defined by Y.Attribute.

        /**
        Returns an HTML-escaped version of the value of the specified string
        attribute. The value is escaped using `Y.Escape.html()`.

        @method getAsHTML
        @param {String} name Attribute name or object property path.
        @return {String} HTML-escaped attribute value.
        **/
        getAsHTML: function (name) {
            var value = this.get(name);
            return Y.Escape.html(Lang.isValue(value) ? String(value) : '');
        },

        /**
        Returns a URL-encoded version of the value of the specified string
        attribute. The value is encoded using the native `encodeURIComponent()`
        function.

        @method getAsURL
        @param {String} name Attribute name or object property path.
        @return {String} URL-encoded attribute value.
        **/
        getAsURL: function (name) {
            var value = this.get(name);
            return encodeURIComponent(Lang.isValue(value) ? String(value) : '');
        },

        /**
        Returns `true` if any attribute of this model has been changed since the
        model was last saved.

        New models (models for which `isNew()` returns `true`) are implicitly
        considered to be "modified" until the first time they're saved.

        @method isModified
        @return {Boolean} `true` if this model has changed since it was last saved,
          `false` otherwise.
        **/
        isModified: function () {
            return this.isNew() || !YObject.isEmpty(this.changed);
        },

        /**
        Returns `true` if this model is "new", meaning it hasn't been saved since it
        was created.

        Newness is determined by checking whether the model's `id` attribute has
        been set. An empty id is assumed to indicate a new model, whereas a
        non-empty id indicates a model that was either loaded or has been saved
        since it was created.

        @method isNew
        @return {Boolean} `true` if this model is new, `false` otherwise.
        **/
        isNew: function () {
            return !Lang.isValue(this.get('id'));
        },

        /**
        Loads this model from the server.

        This method delegates to the `sync()` method to perform the actual load
        operation, which is an asynchronous action. Specify a _callback_ function to
        be notified of success or failure.

        A successful load operation will fire a `load` event, while an unsuccessful
        load operation will fire an `error` event with the `src` value "load".

        If the load operation succeeds and one or more of the loaded attributes
        differ from this model's current attributes, a `change` event will be fired.

        @method load
        @param {Object} [options] Options to be passed to `sync()` and to `set()`
          when setting the loaded attributes. It's up to the custom sync
          implementation to determine what options it supports or requires, if any.
        @param {callback} [callback] Called when the sync operation finishes.
          @param {Error|null} callback.err If an error occurred, this parameter will
            contain the error. If the sync operation succeeded, _err_ will be
            `null`.
          @param {Any} callback.response The server's response. This value will
            be passed to the `parse()` method, which is expected to parse it and
            return an attribute hash.
        @chainable
        **/
        load: function (options, callback) {
            var self = this;

            // Allow callback as only arg.
            if (typeof options === 'function') {
                callback = options;
                options  = {};
            }

            options = options || {};

            self.sync('read', options, function (err, response) {
                self._handleRead(err, response, options, callback);
            });

            return self;
        },

        /**
        Called to parse the _response_ when the model is loaded from the server.
        This method receives a server _response_ and is expected to return an
        attribute hash.

        The default implementation assumes that _response_ is either an attribute
        hash or a JSON string that can be parsed into an attribute hash. If
        _response_ is a JSON string and either `Y.JSON` or the native `JSON` object
        are available, it will be parsed automatically. If a parse error occurs, an
        `error` event will be fired and the model will not be updated.

        You may override this method to implement custom parsing logic if necessary.

        @method parse
        @param {Any} response Server response.
        @return {Object} Attribute hash.
        **/
        parse: function (response) {
            if (typeof response === 'string') {
                try {
                    return Y.JSON.parse(response);
                } catch (ex) {
                    return null;
                }
            }

            return response;
        },

        /**
        Saves this model to the server.

        This method delegates to the `sync()` method to perform the actual save
        operation, which is an asynchronous action. Specify a _callback_ function to
        be notified of success or failure.

        A successful save operation will fire a `save` event, while an unsuccessful
        save operation will fire an `error` event with the `src` value "save".

        If the save operation succeeds and one or more of the attributes returned in
        the server's response differ from this model's current attributes, a
        `change` event will be fired.

        @method save
        @param {Object} [options] Options to be passed to `sync()` and to `set()`
          when setting synced attributes. It's up to the custom sync implementation
          to determine what options it supports or requires, if any.
        @param {Function} [callback] Called when the sync operation finishes.
          @param {Error|null} callback.err If an error occurred or validation
            failed, this parameter will contain the error. If the sync operation
            succeeded, _err_ will be `null`.
          @param {Any} callback.response The server's response. This value will
            be passed to the `parse()` method, which is expected to parse it and
            return an attribute hash.
        @chainable
        **/
        save: function (options, callback) {
            var self = this;

            // Allow callback as only arg.
            if (typeof options === 'function') {
                callback = options;
                options  = {};
            }

            options = options || {};

            self._validate(self.toJSON(), function (err) {
                var action;

                if (err) {
                    if (callback) {
                        callback.call(null, err);
                    }

                    return;
                }

                action = self.isNew() ? 'create' : 'update';

                self.sync(action, options, function (err, response) {
                    self._handleSave(err, response, options, callback);
                });
            });

            return self;
        },

        /**
        Sets the value of a single attribute. If model validation fails, the
        attribute will not be set and an `error` event will be fired.

        Use `setAttrs()` to set multiple attributes at once.

        @example
            model.set('foo', 'bar');

        @method set
        @param {String} name Attribute name or object property path.
        @param {any} value Value to set.
        @param {Object} [options] Data to be mixed into the event facade of the
            `change` event(s) for these attributes.
          @param {Boolean} [options.silent=false] If `true`, no `change` event will
              be fired.
        @chainable
        **/
        set: function (name, value, options) {
            var attributes = {};

            attributes[name] = value;

            return this.setAttrs(attributes, options);
        },

        /**
        TODO: Update description.

        Sets the values of multiple attributes at once. If model validation fails,
        the attributes will not be set and an `error` event will be fired.

        @example
            model.setAttrs({
                foo: 'bar',
                baz: 'quux'
            });

        @method setAttrs
        @param {Object} attributes Hash of attribute names and values to set.
        @param {Object} [options] Data to be mixed into the event facade of the
            `change` event(s) for these attributes.
          @param {Boolean} [options.silent=false] If `true`, no `change` event will
              be fired.
        @chainable
        **/
        setAttrs: function (attributes, options) {
            var idAttribute = this.idAttribute,
                changed,
                e,
                key,
                lastChange,
                transaction;

            options = options || {};
            transaction = options._transaction = {};

            // When a custom id attribute is in use, always keep the default `id`
            // attribute in sync.
            if (idAttribute !== 'id') {
                // So we don't modify someone else's object.
                attributes = Y.merge(attributes);

                if (YObject.owns(attributes, idAttribute)) {
                    attributes.id = attributes[idAttribute];
                } else if (YObject.owns(attributes, 'id')) {
                    attributes[idAttribute] = attributes.id;
                }
            }

            for (key in attributes) {
                if (attributes.hasOwnProperty(key) && YObject.owns(attributes, key)) {
                    this._setAttr(key, attributes[key], options);
                }
            }

            this._processAttrsTransaction(transaction, options);

            return this;
        },

        /**
        Override this method to provide a custom persistence implementation for this
        model. The default just calls the callback without actually doing anything.

        This method is called internally by `load()`, `save()`, and `destroy()`.

        @method sync
        @param {String} action Sync action to perform. May be one of the following:

          * `create`: Store a newly-created model for the first time.
          * `delete`: Delete an existing model.
          * `read`  : Load an existing model.
          * `update`: Update an existing model.

        @param {Object} [options] Sync options. It's up to the custom sync
          implementation to determine what options it supports or requires, if any.
        @param {Function} [callback] Called when the sync operation finishes.
          @param {Error|null} callback.err If an error occurred, this parameter will
            contain the error. If the sync operation succeeded, _err_ will be
            falsy.
          @param {Any} [callback.response] The server's response.
        **/
        sync: function () {
            var yarray = YArray, // jslint :(
                callback = yarray(arguments, 0, true).pop();

            if (typeof callback === 'function') {
                callback();
            }
        },

        /**
        Returns a copy of this model's attributes that can be passed to
        `Y.JSON.stringify()` or used for other nefarious purposes.

        The `clientId` attribute is not included in the returned object.

        If you've specified a custom attribute name in the `idAttribute` property,
        the default `id` attribute will not be included in the returned object.

        Note: The ECMAScript 5 specification states that objects may implement a
        `toJSON` method to provide an alternate object representation to serialize
        when passed to `JSON.stringify(obj)`.  This allows class instances to be
        serialized as if they were plain objects.  This is why Model's `toJSON`
        returns an object, not a JSON string.

        See <http://es5.github.com/#x15.12.3> for details.

        @method toJSON
        @return {Object} Copy of this model's attributes.
        **/
        toJSON: function () {
            var attrs = this.getAttrs();

            delete attrs.clientId;
            delete attrs.destroyed;
            delete attrs.initialized;

            if (this.idAttribute !== 'id') {
                delete attrs.id;
            }

            return attrs;
        },

        /**
        Reverts the last change to the model.

        If an _attrNames_ array is provided, then only the named attributes will be
        reverted (and only if they were modified in the previous change). If no
        _attrNames_ array is provided, then all changed attributes will be reverted
        to their previous values.

        Note that only one level of undo is available: from the current state to the
        previous state. If `undo()` is called when no previous state is available,
        it will simply do nothing.

        @method undo
        @param {Array} [attrNames] Array of specific attribute names to revert. If
          not specified, all attributes modified in the last change will be
          reverted.
        @param {Object} [options] Data to be mixed into the event facade of the
            change event(s) for these attributes.
          @param {Boolean} [options.silent=false] If `true`, no `change` event will
              be fired.
        @chainable
        **/
        undo: function (attrNames, options) {
            var lastChange  = this.lastChange,
                idAttribute = this.idAttribute,
                toUndo      = {},
                needUndo;

            attrNames = attrNames || YObject.keys(lastChange);

            YArray.each(attrNames, function (name) {
                if (YObject.owns(lastChange, name)) {
                    // Don't generate a double change for custom id attributes.
                    name = name === idAttribute ? 'id' : name;

                    needUndo     = true;
                    toUndo[name] = lastChange[name].prevVal;
                }
            });

            return needUndo ? this.setAttrs(toUndo, options) : this;
        },

        /**
        Override this method to provide custom validation logic for this model.

        While attribute-specific validators can be used to validate individual
        attributes, this method gives you a hook to validate a hash of all
        attributes before the model is saved. This method is called automatically
        before `save()` takes any action. If validation fails, the `save()` call
        will be aborted.

        In your validation method, call the provided `callback` function with no
        arguments to indicate success. To indicate failure, pass a single argument,
        which may contain an error message, an array of error messages, or any other
        value. This value will be passed along to the `error` event.

        @example

            model.validate = function (attrs, callback) {
                if (attrs.pie !== true) {
                    // No pie?! Invalid!
                    callback('Must provide pie.');
                    return;
                }

                // Success!
                callback();
            };

        @method validate
        @param {Object} attrs Attribute hash containing all model attributes to
            be validated.
        @param {Function} callback Validation callback. Call this function when your
            validation logic finishes. To trigger a validation failure, pass any
            value as the first argument to the callback (ideally a meaningful
            validation error of some kind).

            @param {Any} [callback.err] Validation error. Don't provide this
                argument if validation succeeds. If validation fails, set this to an
                error message or some other meaningful value. It will be passed
                along to the resulting `error` event.
        **/
        validate: function (attrs, callback) {
            if (callback) {
                callback();
            }
        },

        // -- Protected Methods ----------------------------------------------------

        /**
        Duckpunches the `addAttr` method provided by `Y.Attribute` to keep the
        `id` attribute’s value and a custom id attribute’s (if provided) value
        in sync when adding the attributes to the model instance object.

        Marked as protected to hide it from Model's public API docs, even though
        this is a public method in Attribute.

        @method addAttr
        @param {String} name The name of the attribute.
        @param {Object} config An object with attribute configuration property/value
          pairs, specifying the configuration for the attribute.
        @param {Boolean} lazy (optional) Whether or not to add this attribute lazily
          (on the first call to get/set).
        @return {Object} A reference to the host object.
        @chainable
        @protected
        **/
        addAttr: function (name, config, lazy) {
            var idAttribute = this.idAttribute,
                idAttrCfg,
                id;

            if (idAttribute && name === idAttribute) {
                idAttrCfg = this._isLazyAttr('id') || this._getAttrCfg('id');
                id        = config.value === config.defaultValue ? null : config.value;

                if (!Lang.isValue(id)) {
                    // Hunt for the id value.
                    id = idAttrCfg.value === idAttrCfg.defaultValue ? null : idAttrCfg.value;

                    if (!Lang.isValue(id)) {
                        // No id value provided on construction, check defaults.
                        id = Lang.isValue(config.defaultValue) ?
                                config.defaultValue :
                                idAttrCfg.defaultValue;
                    }
                }

                config.value = id;

                // Make sure `id` is in sync.
                if (idAttrCfg.value !== id) {
                    idAttrCfg.value = id;

                    if (this._isLazyAttr('id')) {
                        this._state.add('id', 'lazy', idAttrCfg);
                    } else {
                        this._state.add('id', 'value', id);
                    }
                }
            }

            return AttributeCore.prototype.addAttr.apply(this, arguments);
        },

        /**
        Calls the public, overrideable `parse()` method and returns the result.

        Override this method to provide a custom pre-parsing implementation. This
        provides a hook for custom persistence implementations to "prep" a response
        before calling the `parse()` method.

        @method _parse
        @param {Any} response Server response.
        @return {Object} Attribute hash.
        @protected
        @see Model.parse()
        @since 3.7.0
        **/
        _parse: function (response) {
            return this.parse(response);
        },

        // TODO: Document method.
        // TODO: Think if this is a good name.
        _processAttrsTransaction: function (transaction, options) {
            var changed, e, key, lastChange;

            if (!YObject.isEmpty(transaction)) {
                changed    = this.changed;
                lastChange = this.lastChange = {};

                for (key in transaction) {
                    if (transaction.hasOwnProperty(key) && YObject.owns(transaction, key)) {
                        e = transaction[key];

                        changed[key] = e.newVal;

                        lastChange[key] = {
                            newVal : e.newVal,
                            prevVal: e.prevVal,
                            src    : e.src || null
                        };
                    }
                }
            }
        },

        // TODO: Document method.
        // TODO: Think if this is a good name.
        _handleRead: function (err, response, options, callback) {
            var parsed;

            if (!err) {
                parsed = this._parse(response);
                this.setAttrs(parsed, options);
                this.changed = {};
            }

            if (callback) {
                callback(err, response);
            }
        },

        // TODO: Document method.
        // TODO: Think if this is a good name.
        _handleSave: function (err, response, options, callback) {
            var parsed;

            if (!err) {
                if (response) {
                    parsed = this._parse(response);
                    this.setAttrs(parsed, options);
                }

                this.changed = {};
            }

            if (callback) {
                callback(err, response);
            }
        },

        /**
        TODO: Update method description.

        Calls the public, overridable `validate()` method and fires an `error` event
        if validation fails.

        @method _validate
        @param {Object} attributes Attribute hash.
        @param {Function} callback Validation callback.
            @param {Any} [callback.err] Value on failure, non-value on success.
        @protected
        **/
        _validate: function (attributes, callback) {
            this.validate(attributes, function (err) {
                if (Lang.isValue(err)) {
                    callback(err);
                } else {
                    callback();
                }
            });
        }
    };

    Y.Model.Vanilla = ModelVanilla;
    Y.mix(Y.Model.Vanilla, AttributeCore, false, null, 1);
    Y.mix(Y.Model.Vanilla, AttributeExtras, false, null, 1);

}, "", { requires: ["attribute-core", "attribute-extras", "escape", "json-parse", "model"]});