Model Class - YUI Library (original) (raw)

Attribute-based data model with APIs for getting, setting, validating, and syncing attribute values, as well as events for being notified of model changes.

In most cases, you'll want to create your own subclass of Y.Model and customize it to meet your needs. In particular, the sync() and validate()methods are meant to be overridden by custom implementations. You may also want to override the parse() method to parse non-generic server responses.

Constructor

Item Index

Methods

Methods

_addAttrs

private

Implementation behind the public addAttrs method.

This method is invoked directly by get if it encounters a scenario in which an attribute's valueFn attempts to obtain the value an attribute in the same group of attributes, which has not yet been added (on demand initialization).

Parameters:

_addLazyAttr

private

Finishes initializing an attribute which has been lazily added.

Parameters:

_addOutOfOrder

private

Utility method used by get/set to add attributes encountered out of order when calling addAttrs().

For example, if:

this.addAttrs({
     foo: {
         setter: function() {
            // make sure this bar is available when foo is added
            this.get("bar");
         }
     },
     bar: {
         value: ...
     }
});

Parameters:

_aggregateAttrs

Object private

A helper method, used by _initHierarchyData to aggregate attribute configuration across the instances class hierarchy.

The method will protect the attribute configuration value to protect the statically defined default value in ATTRS if required (if the value is an object literal, array or the attribute configuration has cloneDefaultValue set to shallow or deep).

Parameters:

Returns:

Object:

The aggregate set of ATTRS definitions for the instance

_attrCfgHash

() private

Utility method to define the attribute hash used to filter/whitelist property mixes for this class for iteration performance reasons.

_baseDestroy

() private

Internal destroy implementation for BaseCore

_baseInit

() private

Internal initialization implementation for BaseCore

_cloneDefaultValue

private

This method assumes that the value has already been checked to be an object. Since it's on a critical path, we don't want to re-do the check.

_defAttrChangeFn

private

Default function for attribute change events.

Parameters:

_defDestroyFn

protected

Default destroy event handler

_defInitFn

protected

Default init event handler

Parameters:

_destroyHierarchy

() private

Destroys the class hierarchy for this instance by invoking the destructor method on the prototype of each class in the hierarchy.

_filterAdHocAttrs

Object private

Parameters:

Returns:

Object:

The set of adhoc attributes passed in, in the form of an object with attribute name/configuration pairs.

_fireAttrChange

(

)

private

Utility method to help setup the event payload and fire the attribute change event.

Parameters:

_getAttr

Any protected chainable

Provides the common implementation for the public get method, allowing Attribute hosts to over-ride either method.

See get for argument details.

Parameters:

Returns:

Any:

The value of the attribute.

_getAttrCfg

Object protected

Returns an object with the configuration properties (and value) for the given attribute. If attrName is not provided, returns the configuration properties for all attributes.

Parameters:

Returns:

Object:

The configuration properties for the given attribute, or all attributes.

_getAttrCfgs

() Object protected

Returns an aggregated set of attribute configurations, by traversing the class hierarchy.

Returns:

Object:

The hash of attribute configurations, aggregated across classes in the hierarchy This value is cached the first time the method, or _getClasses, is invoked. Subsequent invocations return the cached value.

_getAttrInitVal

Any private

Returns the initial value of the given attribute from either the default configuration provided, or the over-ridden value if it exists in the set of initValues provided and the attribute is not read-only.

Parameters:

Returns:

Any:

The initial value of the attribute.

_getAttrs

Object protected

Implementation behind the public getAttrs method, to get multiple attribute values.

Parameters:

Returns:

Object:

An object with attribute name/value pairs.

_getClasses

() Function[] protected

Returns the class hierarchy for this object, with BaseCore being the last class in the array.

Returns:

Function[]:

An array of classes (constructor functions), making up the class hierarchy for this object. This value is cached the first time the method, or _getAttrCfgs, is invoked. Subsequent invocations return the cached value.

_getFullType

String private

Returns the fully qualified type, given a short type string. That is, returns "foo:bar" when given "bar" if "foo" is the configured prefix.

NOTE: This method, unlike _getType, does no checking of the value passed in, and is designed to be used with the low level _publish() method, for critical path implementations which need to fast-track publish for performance reasons.

Parameters:

Returns:

String:

The prefixed type, if a prefix is set, otherwise the type passed in

_getInstanceAttrCfgs

Object private

A helper method used to isolate the attrs config for this instance to pass to addAttrs, from the static cached ATTRS for the class.

Parameters:

Returns:

Object:

The set of attributes to be added for this instance, suitable for passing through to addAttrs.

_getStateVal

Any private

Gets the stored value for the attribute, from either the internal state object, or the state proxy if it exits

Parameters:

Returns:

Any:

The stored value of the attribute

_getType

() private

If the instance has a prefix attribute and the event type is not prefixed, the instance prefix is applied to the supplied type.

_hasPotentialSubscribers

Boolean private

Parameters:

Returns:

Boolean:

Whether the event has potential subscribers or not

_initAttrHost

private

Constructor logic for attributes. Initializes the host state, and sets up the inital attributes passed to the constructor.

Parameters:

_initAttribute

() private

Initializes AttributeCore

_initAttrs

protected

Utility method to set up initial attributes defined during construction, either through the constructor.ATTRS property, or explicitly passed in.

Parameters:

_initBase

private

Internal construction logic for BaseCore.

Parameters:

_initHierarchy

private

Initializes the class hierarchy for the instance, which includes initializing attributes for each class defined in the class's static ATTRS property and invoking the initializer method on the prototype of each class in the hierarchy.

Parameters:

_initHierarchyData

() private

A helper method used by _getClasses and _getAttrCfgs, which determines both the array of classes and aggregate set of attribute configurations across the class hierarchy for the instance.

_isLazyAttr

Boolean private

Checks whether or not the attribute is one which has been added lazily and still requires initialization.

Parameters:

Returns:

Boolean:

true if it's a lazily added attribute, false otherwise.

_monitor

private

This is the entry point for the event monitoring system. You can monitor 'attach', 'detach', 'fire', and 'publish'. When configured, these events generate an event. click -> click_attach, click_detach, click_publish -- these can be subscribed to like other events to monitor the event system. Inividual published events can have monitoring turned on or off (publish can't be turned off before it it published) by setting the events 'monitor' config.

Parameters:

_normAttrVals

Object private

Utility method to normalize attribute values. The base implementation simply merges the hash to protect the original.

Parameters:

Returns:

Object:

An object literal with 2 properties - "simple" and "complex", containing simple and complex attribute values respectively keyed by the top level attribute name, or null, if valueHash is falsey.

_parse

Object protected

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.

Parameters:

Returns:

_parseType

() private

Returns an array with the detach key (if provided), and the prefixed event name from _getType Y.on('detachcategory| menu:click', fn)

_preInitEventCfg

private

Handles the special on, after and target properties which allow the user to easily configure on and after listeners as well as bubble targets during construction, prior to init.

Parameters:

_protectAttrs

Object deprecated protected

Utility method to protect an attribute configuration hash, by merging the entire object and the individual attr config objects.

Parameters:

Returns:

Object:

A protected version of the attrs argument.

_publish

(

)

CustomEvent private

The low level event publish implementation. It expects all the massaging to have been done outside of this method. e.g. the type to fullType conversion. It's designed to be a fast path publish, which can be used by critical code paths to improve performance.

Parameters:

Returns:

CustomEvent:

The published event. If called without etOpts or ceOpts, this will be the default CustomEvent instance, and can be configured independently.

_set

Object protected chainable

Allows setting of readOnly/writeOnce attributes. See set for argument details.

Parameters:

Returns:

Object:

A reference to the host object.

_setAttr

(

)

Object protected chainable

Provides the common implementation for the public set and protected _set methods.

See set for argument details.

Parameters:

Returns:

Object:

A reference to the host object.

_setAttrs

Object protected chainable

Implementation behind the public setAttrs method, to set multiple attribute values.

Parameters:

Returns:

Object:

A reference to the host object.

_setAttrVal

(

)

Boolean private

Overrides AttributeCore's _setAttrVal, to register the changed value if it's part of a Model setAttrs transaction.

NOTE: AttributeCore's _setAttrVal is currently private, but until we support coalesced change events in attribute, we need this override.

Parameters:

Returns:

Boolean:

true if the new attribute value was stored, false if not.

_setStateVal

private

Sets the stored value for the attribute, in either the internal state object, or the state proxy if it exits

Parameters:

_validate

protected

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

Parameters:

addAttr

Object protected chainable

Duckpunches the addAttr method provided by Y.Attribute to keep theid 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.

Parameters:

Returns:

Object:

A reference to the host object.

addAttrs

Object chainable

Configures a group of attributes, and sets initial values.

NOTE: This method does not isolate the configuration object by merging/cloning. The caller is responsible for merging/cloning the configuration object if required.

Parameters:

Returns:

Object:

A reference to the host object.

addTarget

chainable

Registers another EventTarget as a bubble target. Bubble order is determined by the order registered. Multiple targets can be specified.

Events can only bubble if emitFacade is true.

Included in the event-custom-complex submodule.

after

(

)

EventHandle

Subscribe to a custom event hosted by this object. The supplied callback will execute after any listeners add via the subscribe method, and after the default function, if configured for the event, has executed.

Parameters:

Returns:

EventHandle:

A subscription handle capable of detaching the subscription

attrAdded

Boolean

Checks if the given attribute has been added to the host

Parameters:

Returns:

Boolean:

true if an attribute with the given name has been added, false if it hasn't. This method will return true for lazily added attributes.

before

()

Executes the callback before a DOM event, custom event or method. If the first argument is a function, it is assumed the target is a method. For DOM and custom events, this is an alias for Y.on.

For DOM and custom events: type, callback, context, 0-n arguments

For methods: callback, object (method host), methodName, context, 0-n arguments

bubble

Boolean

Propagate an event. Requires the event-custom-complex module.

Parameters:

Returns:

Boolean:

the aggregated return value from Event.Custom.fire

destroy

chainable

Destroys this model instance and removes it from its containing lists, if any.

The callback, if one is provided, will be called after the model is destroyed.

If options.remove is true, then this method delegates to the sync()method to delete the model from the persistence layer, which is an asynchronous action. In this case, the callback (if provided) will be called after the sync layer indicates success or failure of the delete operation.

Parameters:

detach

EventTarget

Detach one or more listeners the from the specified event

Parameters:

Returns:

detachAll

Removes all listeners from the specified event. If the event type is not specified, all listeners from all hosted custom events will be removed.

Parameters:

fire

Boolean

Fire a custom event by name. The callback functions will be executed from the context specified when the event was created, and with the following parameters.

The first argument is the event type, and any additional arguments are passed to the listeners as parameters. If the first of these is an object literal, and the event is configured to emit an event facade, that object is mixed into the event facade and the facade is provided in place of the original object.

If the custom event object hasn't been created, then the event hasn't been published and it has no subscribers. For performance sake, we immediate exit in this case. This means the event won't bubble, so if the intention is that a bubble target be notified, the event must be published on this object first.

Parameters:

Returns:

Boolean:

True if the whole lifecycle of the event went through, false if at any point the event propagation was halted.

generateClientId

() String

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.

Returns:

get

Any

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.

Parameters:

Returns:

Any:

Attribute value, or undefined if the attribute doesn't exist.

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'

getAsHTML

String

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

Parameters:

Returns:

String:

HTML-escaped attribute value.

getAsURL

String

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

Parameters:

Returns:

String:

URL-encoded attribute value.

getAttrs

Object

Gets multiple attribute values.

Parameters:

Returns:

Object:

An object with attribute name/value pairs.

getEvent

CustomEvent

Returns the custom event of the provided type has been created, a falsy value otherwise

Parameters:

Returns:

getTargets

()

Returns an array of bubble targets for this object.

init

BaseCore chainable

Init lifecycle method, invoked during construction. Sets up attributes and invokes initializers for the class hierarchy.

Parameters:

Returns:

isModified

() Boolean

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.

Returns:

Boolean:

true if this model has changed since it was last saved,false otherwise.

isNew

() Boolean

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.

Returns:

Boolean:

true if this model is new, false otherwise.

load

chainable

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.

Parameters:

modifyAttr

Updates the configuration of an attribute which has already been added.

The properties which can be modified through this interface are limited to the following subset of attributes, which can be safely modified after a value has already been set on the attribute:

readOnly;

writeOnce;

broadcast; and

getter.

Note: New attributes cannot be added using this interface. New attributes must be added using addAttr, or an appropriate manner for a class which utilises Attributes (e.g. theATTRS property inBase).

Parameters:

on

(

)

EventHandle

Subscribe a callback function to a custom event fired by this object or from an object that bubbles its events to this object.

Callback functions for events published with emitFacade = true will receive an EventFacade as the first argument (typically named "e"). These callbacks can then call e.preventDefault() to disable the behavior published to that event's defaultFn. See the EventFacadeAPI for all available properties and methods. Subscribers to non-emitFacade events will receive the arguments passed to fire()after the event name.

To subscribe to multiple events at once, pass an object as the first argument, where the key:value pairs correspond to the eventName:callback, or pass an array of event names as the first argument to subscribe to all listed events with the same callback.

Returning false from a callback is supported as an alternative to calling e.preventDefault(); e.stopPropagation();. However, it is recommended to use the event methods whenever possible.

Parameters:

Returns:

EventHandle:

A subscription handle capable of detaching that subscription

once

(

)

EventHandle

Listen to a custom event hosted by this object one time. This is the equivalent to on except the listener is immediatelly detached when it is executed.

Parameters:

Returns:

EventHandle:

A subscription handle capable of detaching the subscription

onceAfter

(

)

EventHandle

Listen to a custom event hosted by this object one time. This is the equivalent to after except the listener is immediatelly detached when it is executed.

Parameters:

Returns:

EventHandle:

A subscription handle capable of detaching that subscription

parse

Object

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, anerror event will be fired and the model will not be updated.

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

Parameters:

Returns:

parseType

Array

Takes the type parameter passed to 'on' and parses out the various pieces that could be included in the type. If the event type is passed without a prefix, it will be expanded to include the prefix one is supplied or the event target is configured with a default prefix.

Parameters:

Returns:

Array:

an array containing:

publish

CustomEvent

Creates a new custom event of the specified type. If a custom event by that name already exists, it will not be re-created. In either case the custom event is returned.

Parameters:

Returns:

removeAttr

Removes an attribute from the host object

Parameters:

removeTarget

chainable

Removes a bubble target

reset

Object chainable

Resets the attribute (or all attributes) to its initial value, as long as the attribute is not readOnly, or writeOnce.

Parameters:

Returns:

Object:

A reference to the host object.

save

chainable

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, achange event will be fired.

Parameters:

set

chainable

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.

Parameters:

Example:

setAttrs

chainable

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.

Parameters:

Example:

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

subscribe

() deprecated

subscribe to an event

sync

(

)

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(), and their implementations rely on the callback being called. This effectively means that when a callback is provided, it must be called at some point for the class to operate correctly.

Parameters:

toJSON

() Object

Returns a copy of this model's attributes that can be passed toY.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 atoJSON 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 toJSONreturns an object, not a JSON string.

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

Returns:

Object:

Copy of this model's attributes.

toString

() String

Default toString implementation. Provides the constructor NAME and the instance guid, if set.

Returns:

String:

String representation for this object

undo

(

)

chainable

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.

Parameters:

unsubscribe

() deprecated

detach a listener

unsubscribeAll

deprecated

Removes all listeners from the specified event. If the event type is not specified, all listeners from all hosted custom events will be removed.

Parameters:

validate

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.

Parameters:

Example:

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

    // Success!
    callback();
};

Properties

_allowAdHocAttrs

Boolean protected

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 subclassY.Model and declare all those attributes first.

Default: true

_isYUIModel

Boolean protected

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

Default: true

changed

Object

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

Default: {}

idAttribute

String

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.

Default: `'id'`

lastChange

Object

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

Default: {}

lists

ModelList[]

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.

Default: `[]`

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.
});

name

String deprecated

The string used to identify the class of this object.

Attributes

clientId

String readonly

A client-only identifier for this model.

Like the id attribute, clientId may be used to retrieve model instances from lists. Unlike the id attribute, clientId is automatically generated, and is only intended to be used on the client during the current pageview.

Fires event clientIdChange

Fires when the value for the configuration attribute clientId is changed. You can listen for the event using the on method if you wish to be notified before the attribute's value has changed, or using the after method if you wish to be notified after the attribute's value has changed.

Parameters:

destroyed

Boolean readonly

Flag indicating whether or not this object has been through the destroy lifecycle phase.

Default: false

Fires event destroyedChange

Fires when the value for the configuration attribute destroyed is changed. You can listen for the event using the on method if you wish to be notified before the attribute's value has changed, or using the after method if you wish to be notified after the attribute's value has changed.

Parameters:

id

String | Number | Null

A unique identifier for this model. Among other things, this id may be used to retrieve model instances from lists, so it should be unique.

If the id is empty, this model instance is assumed to represent a new item that hasn't yet been saved.

If you would prefer to use a custom attribute as this model's id instead of using the id attribute (for example, maybe you'd rather use _idor uid as the primary id), you may set the idAttribute property to the name of your custom id attribute. The id attribute will then act as an alias for your custom attribute.

Default: `null`

Fires event idChange

Fires when the value for the configuration attribute id is changed. You can listen for the event using the on method if you wish to be notified before the attribute's value has changed, or using the after method if you wish to be notified after the attribute's value has changed.

Parameters:

initialized

Boolean readonly

Flag indicating whether or not this object has been through the init lifecycle phase.

Default: false

Fires event initializedChange

Fires when the value for the configuration attribute initialized is changed. You can listen for the event using the on method if you wish to be notified before the attribute's value has changed, or using the after method if you wish to be notified after the attribute's value has changed.

Parameters:

Events

change

Fired when one or more attributes on this model are changed.

Event Payload:

destroy

Lifecycle event for the destroy phase, fired prior to destruction. Invoking the preventDefault method on the event object provided to subscribers will prevent destruction from proceeding.

Subscribers to the "after" moment of this event, will be notified after destruction is complete (and as a result cannot prevent destruction).

error

Fired when an error occurs, such as when the model doesn't validate or when a sync layer response can't be parsed.

Event Payload:

init

Lifecycle event for the init phase, fired prior to initialization. Invoking the preventDefault() method on the event object provided to subscribers will prevent initialization from occuring.

Subscribers to the "after" momemt of this event, will be notified after initialization of the object is complete (and therefore cannot prevent initialization).

Event Payload:

load

Fired after model attributes are loaded from a sync layer.

Event Payload:

save

Fired after model attributes are saved to a sync layer.

Event Payload: