/**
* The base module provides the Base class, which objects requiring attribute and custom event support can extend.
* The module also provides two ways to reuse code - An augmentable Plugin.Host interface which provides plugin support
* (which is augmented to the Base class) and Base.build which provides a way to
* build custom classes using extensions.
*
* @module base
*/
/**
* The base-base submodule provides the Base class without the Plugin support, provided by Plugin.Host,
* and without the extension support provided by Base.build.
*
* @module base
* @submodule base-base
*/
var O = Y.Object,
L = Y.Lang,
DOT = ".",
DESTROY = "destroy",
INIT = "init",
INITIALIZED = "initialized",
DESTROYED = "destroyed",
INITIALIZER = "initializer",
OBJECT_CONSTRUCTOR = Object.prototype.constructor,
DEEP = "deep",
SHALLOW = "shallow",
DESTRUCTOR = "destructor",
Attribute = Y.Attribute;
/**
* <p>
* A base class which objects requiring attributes and custom event support can
* extend. Base also handles the chaining of initializer and destructor methods across
* the hierarchy as part of object construction and destruction. Additionally, attributes configured
* through the static <a href="#property_Base.ATTRS">ATTRS</a> property for each class
* in the hierarchy will be initialized by Base.
* </p>
*
* <p>
* The static <a href="#property_Base.NAME">NAME</a> property of each class extending
* from Base will be used as the identifier for the class, and is used by Base to prefix
* all events fired by instances of that class.
* </p>
* @class Base
* @constructor
* @uses Attribute
* @uses Plugin.Host
*
* @param {Object} config Object with configuration property name/value pairs
*/
function Base() {
Y.log('constructor called', 'life', 'base');
Attribute.call(this);
// If Plugin.Host has been augmented [ through base-pluginhost ], setup it's
// initial state, but don't initialize Plugins yet. That's done after initialization.
var PluginHost = Y.Plugin && Y.Plugin.Host;
if (this._initPlugins && PluginHost) {
PluginHost.call(this);
}
if (this._lazyAddAttrs !== false) { this._lazyAddAttrs = true; }
this.init.apply(this, arguments);
}
/**
* The list of properties which can be configured for
* each attribute (e.g. setter, getter, writeOnce, readOnly etc.)
*
* @property Base._ATTR_CFG
* @type Array
* @static
* @private
*/
Base._ATTR_CFG = Attribute._ATTR_CFG.concat("cloneDefaultValue");
/**
* <p>
* The string to be used to identify instances of
* this class, for example in prefixing events.
* </p>
* <p>
* Classes extending Base, should define their own
* static NAME property, which should be camelCase by
* convention (e.g. MyClass.NAME = "myClass";).
* </p>
* @property Base.NAME
* @type String
* @static
*/
Base.NAME = "base";
/**
* The default set of attributes which will be available for instances of this class, and
* their configuration. In addition to the configuration properties listed by
* Attribute's <a href="Attribute.html#method_addAttr">addAttr</a> method, the attribute
* can also be configured with a "cloneDefaultValue" property, which defines how the statically
* defined value field should be protected ("shallow", "deep" and false are supported values).
*
* By default if the value is an object literal or an array it will be "shallow" cloned, to
* protect the default value.
*
* @property Base.ATTRS
* @type Object
* @static
*/
Base.ATTRS = {
/**
* Flag indicating whether or not this object
* has been through the init lifecycle phase.
*
* @attribute initialized
* @readonly
* @default false
* @type boolean
*/
initialized: {
readOnly:true,
value:false
},
/**
* Flag indicating whether or not this object
* has been through the destroy lifecycle phase.
*
* @attribute destroyed
* @readonly
* @default false
* @type boolean
*/
destroyed: {
readOnly:true,
value:false
}
};
Base.prototype = {
/**
* Init lifecycle method, invoked during construction.
* Fires the init event prior to setting up attributes and
* invoking initializers for the class hierarchy.
*
* @method init
* @final
* @chainable
* @param {Object} config Object with configuration property name/value pairs
* @return {Base} A reference to this object
*/
init: function(config) {
Y.log('init called', 'life', 'base');
/**
* The string used to identify the class of this object.
*
* @deprecated Use this.constructor.NAME
* @property name
* @type String
*/
this._yuievt.config.prefix = this.name = this.constructor.NAME;
/**
* <p>
* 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.
* </p>
* <p>
* Subscribers to the "after" momemt of this event, will be notified
* after initialization of the object is complete (and therefore
* cannot prevent initialization).
* </p>
*
* @event init
* @preventable _defInitFn
* @param {EventFacade} e Event object, with a cfg property which
* refers to the configuration object passed to the constructor.
*/
this.publish(INIT, {
queuable:false,
defaultFn:this._defInitFn
});
if (config) {
if (config.on) {
this.on(config.on);
}
if (config.after) {
this.after(config.after);
}
}
this.fire(INIT, {cfg: config});
return this;
},
/**
* <p>
* Destroy lifecycle method. Fires the destroy
* event, prior to invoking destructors for the
* class hierarchy.
* </p>
* <p>
* Subscribers to the destroy
* event can invoke preventDefault on the event object, to prevent destruction
* from proceeding.
* </p>
* @method destroy
* @return {Base} A reference to this object
* @final
* @chainable
*/
destroy: function() {
Y.log('destroy called', 'life', 'base');
/**
* <p>
* 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.
* </p>
* <p>
* Subscribers to the "after" moment of this event, will be notified
* after destruction is complete (and as a result cannot prevent
* destruction).
* </p>
* @event destroy
* @preventable _defDestroyFn
* @param {EventFacade} e Event object
*/
this.publish(DESTROY, {
queuable:false,
defaultFn: this._defDestroyFn
});
this.fire(DESTROY);
return this;
},
/**
* Default init event handler
*
* @method _defInitFn
* @param {EventFacade} e Event object, with a cfg property which
* refers to the configuration object passed to the constructor.
* @protected
*/
_defInitFn : function(e) {
this._initHierarchy(e.cfg);
if (this._initPlugins) {
// Need to initPlugins manually, to handle constructor parsing, static Plug parsing
this._initPlugins(e.cfg);
}
this._set(INITIALIZED, true);
},
/**
* Default destroy event handler
*
* @method _defDestroyFn
* @param {EventFacade} e Event object
* @protected
*/
_defDestroyFn : function(e) {
this._destroyHierarchy();
if (this._destroyPlugins) {
this._destroyPlugins();
}
this._set(DESTROYED, true);
},
/**
* Returns the class hierarchy for this object, with Base being the last class in the array.
*
* @method _getClasses
* @protected
* @return {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.
*/
_getClasses : function() {
if (!this._classes) {
this._initHierarchyData();
}
return this._classes;
},
/**
* Returns an aggregated set of attribute configurations, by traversing the class hierarchy.
*
* @method _getAttrCfgs
* @protected
* @return {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.
*/
_getAttrCfgs : function() {
if (!this._attrs) {
this._initHierarchyData();
}
return this._attrs;
},
/**
* A helper method used when processing ATTRS across the class hierarchy during
* initialization. Returns a disposable object with the attributes defined for
* the provided class, extracted from the set of all attributes passed in .
*
* @method _filterAttrCfs
* @private
*
* @param {Function} clazz The class for which the desired attributes are required.
* @param {Object} allCfgs The set of all attribute configurations for this instance.
* Attributes will be removed from this set, if they belong to the filtered class, so
* that by the time all classes are processed, allCfgs will be empty.
*
* @return {Object} The set of attributes belonging to the class passed in, in the form
* of an object with attribute name/configuration pairs.
*/
_filterAttrCfgs : function(clazz, allCfgs) {
var cfgs = null, attr, attrs = clazz.ATTRS;
if (attrs) {
for (attr in attrs) {
if (attrs.hasOwnProperty(attr) && allCfgs[attr]) {
cfgs = cfgs || {};
cfgs[attr] = allCfgs[attr];
delete allCfgs[attr];
}
}
}
return cfgs;
},
/**
* 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.
*
* @method _initHierarchyData
* @private
*/
_initHierarchyData : function() {
var c = this.constructor,
classes = [],
attrs = [];
while (c) {
// Add to classes
classes[classes.length] = c;
// Add to attributes
if (c.ATTRS) {
attrs[attrs.length] = c.ATTRS;
}
c = c.superclass ? c.superclass.constructor : null;
}
this._classes = classes;
this._attrs = this._aggregateAttrs(attrs);
},
/**
* A helper method, used by _initHierarchyData to aggregate
* attribute configuration across the instances class hierarchy.
*
* The method will potect 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).
*
* @method _aggregateAttrs
* @private
* @param {Array} allAttrs An array of ATTRS definitions across classes in the hierarchy
* (subclass first, Base last)
* @return {Object} The aggregate set of ATTRS definitions for the instance
*/
_aggregateAttrs : function(allAttrs) {
var attr,
attrs,
cfg,
val,
path,
i,
clone,
cfgProps = Base._ATTR_CFG,
aggAttrs = {};
if (allAttrs) {
for (i = allAttrs.length-1; i >= 0; --i) {
attrs = allAttrs[i];
for (attr in attrs) {
if (attrs.hasOwnProperty(attr)) {
// Protect config passed in
cfg = Y.mix({}, attrs[attr], true, cfgProps);
val = cfg.value;
clone = cfg.cloneDefaultValue;
if (val) {
if ( (clone === undefined && (OBJECT_CONSTRUCTOR === val.constructor || L.isArray(val))) || clone === DEEP || clone === true) {
Y.log('Cloning default value for attribute:' + attr, 'info', 'base');
cfg.value = Y.clone(val);
} else if (clone === SHALLOW) {
Y.log('Merging default value for attribute:' + attr, 'info', 'base');
cfg.value = Y.merge(val);
}
// else if (clone === false), don't clone the static default value.
// It's intended to be used by reference.
}
path = null;
if (attr.indexOf(DOT) !== -1) {
path = attr.split(DOT);
attr = path.shift();
}
if (path && aggAttrs[attr] && aggAttrs[attr].value) {
O.setValue(aggAttrs[attr].value, path, val);
} else if (!path){
if (!aggAttrs[attr]) {
aggAttrs[attr] = cfg;
} else {
Y.mix(aggAttrs[attr], cfg, true, cfgProps);
}
}
}
}
}
}
return aggAttrs;
},
/**
* Initializes the class hierarchy for the instance, which includes
* initializing attributes for each class defined in the class's
* static <a href="#property_Base.ATTRS">ATTRS</a> property and
* invoking the initializer method on the prototype of each class in the hierarchy.
*
* @method _initHierarchy
* @param {Object} userVals Object with configuration property name/value pairs
* @private
*/
_initHierarchy : function(userVals) {
var lazy = this._lazyAddAttrs,
constr,
constrProto,
ci,
ei,
el,
classes = this._getClasses(),
attrCfgs = this._getAttrCfgs();
for (ci = classes.length-1; ci >= 0; ci--) {
constr = classes[ci];
constrProto = constr.prototype;
if (constr._yuibuild && constr._yuibuild.exts && !constr._yuibuild.dynamic) {
for (ei = 0, el = constr._yuibuild.exts.length; ei < el; ei++) {
constr._yuibuild.exts[ei].apply(this, arguments);
}
}
this.addAttrs(this._filterAttrCfgs(constr, attrCfgs), userVals, lazy);
if (constrProto.hasOwnProperty(INITIALIZER)) {
constrProto.initializer.apply(this, arguments);
}
}
},
/**
* Destroys the class hierarchy for this instance by invoking
* the descructor method on the prototype of each class in the hierarchy.
*
* @method _destroyHierarchy
* @private
*/
_destroyHierarchy : function() {
var constr,
constrProto,
ci, cl,
classes = this._getClasses();
for (ci = 0, cl = classes.length; ci < cl; ci++) {
constr = classes[ci];
constrProto = constr.prototype;
if (constrProto.hasOwnProperty(DESTRUCTOR)) {
constrProto.destructor.apply(this, arguments);
}
}
},
/**
* Default toString implementation. Provides the constructor NAME
* and the instance ID.
*
* @method toString
* @return {String} String representation for this object
*/
toString: function() {
return this.constructor.NAME + "[" + Y.stamp(this) + "]";
}
};
// Straightup augment, no wrapper functions
Y.mix(Base, Attribute, false, null, 1);
// Fix constructor
Base.prototype.constructor = Base;
Y.Base = Base;
// Fix constructor
Base.prototype.constructor = Base;