File yui3/src/base/js/BaseCore.js
/**
* 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 - It augments Base with the Plugin.Host interface which provides
* plugin support and also provides the BaseCore.build method which provides a way to build custom classes using extensions.
*
* @module base
*/
/**
* <p>The base-core module provides the BaseCore class, the lightest version of Base,
* which provides Base's basic lifecycle management and ATTRS construction support,
* but doesn't fire init/destroy or attribute change events.</p>
*
* <p>It mixes in AttributeCore, which is the lightest version of Attribute</p>
*
* @module base
* @submodule base-core
*/
var O = Y.Object,
L = Y.Lang,
DOT = ".",
INITIALIZED = "initialized",
DESTROYED = "destroyed",
INITIALIZER = "initializer",
VALUE = "value",
OBJECT_CONSTRUCTOR = Object.prototype.constructor,
DEEP = "deep",
SHALLOW = "shallow",
DESTRUCTOR = "destructor",
AttributeCore = Y.AttributeCore,
_wlmix = function(r, s, wlhash) {
var p;
for (p in s) {
if(wlhash[p]) {
r[p] = s[p];
}
}
return r;
};
/**
* The BaseCore class, is the lightest version of Base, and provides Base's
* basic lifecycle management and ATTRS construction support, but doesn't
* fire init/destroy or attribute change events.
*
* BaseCore 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_BaseCore.ATTRS">ATTRS</a>
* property for each class in the hierarchy will be initialized by BaseCore.
*
* Classes which require attribute support, but don't intend to use/expose attribute
* change events can extend BaseCore instead of Base for optimal kweight and
* runtime performance.
*
* **3.11.0 BACK COMPAT NOTE FOR COMPONENT DEVELOPERS**
*
* Prior to version 3.11.0, ATTRS would get added a class at a time. That is:
*
* <pre>
* for each (class in the hierarchy) {
* Call the class Extension constructors.
*
* Add the class ATTRS.
*
* Call the class initializer
* Call the class Extension initializers.
* }
* </pre>
*
* As of 3.11.0, ATTRS from all classes in the hierarchy are added in one `addAttrs` call
* before **any** initializers are called. That is, the flow becomes:
*
* <pre>
* for each (class in the hierarchy) {
* Call the class Extension constructors.
* }
*
* Add ATTRS for all classes
*
* for each (class in the hierarchy) {
* Call the class initializer.
* Call the class Extension initializers.
* }
* </pre>
*
* Adding all ATTRS at once fixes subtle edge-case issues with subclass ATTRS overriding
* superclass `setter`, `getter` or `valueFn` definitions and being unable to get/set attributes
* defined by the subclass. It also leaves us with a cleaner order of operation flow moving
* forward.
*
* However, it may require component developers to upgrade their components, for the following
* scenarios:
*
* 1. It impacts components which may have `setter`, `getter` or `valueFn` code which
* expects a superclass' initializer to have run.
*
* This is expected to be rare, but to support it, Base now supports a `_preAddAttrs()`, method
* hook (same signature as `addAttrs`). Components can implement this method on their prototype
* for edge cases which do require finer control over the order in which attributes are added
* (see widget-htmlparser for example).
*
* 2. Extension developers may need to move code from Extension constructors to `initializer`s
*
* Older extensions, which were written before `initializer` support was added, had a lot of
* initialization code in their constructors. For example, code which acccessed superclass
* attributes. With the new flow this code would not be able to see attributes. The recommendation
* is to move this initialization code to an `initializer` on the Extension, which was the
* recommendation for anything created after `initializer` support for Extensions was added.
*
* @class BaseCore
* @constructor
* @uses AttributeCore
* @param {Object} cfg Object with configuration property name/value pairs.
* The object can be used to provide initial values for the objects published
* attributes.
*/
function BaseCore(cfg) {
if (!this._BaseInvoked) {
this._BaseInvoked = true;
Y.log('constructor called', 'life', 'base');
this._initBase(cfg);
}
else { Y.log('Based constructor called more than once. Ignoring duplicate calls', 'life', 'base'); }
}
/**
* The list of properties which can be configured for each attribute
* (e.g. setter, getter, writeOnce, readOnly etc.)
*
* @property _ATTR_CFG
* @type Array
* @static
* @private
*/
BaseCore._ATTR_CFG = AttributeCore._ATTR_CFG.concat("cloneDefaultValue");
/**
* The array of non-attribute configuration properties supported by this class.
*
* For example `BaseCore` defines a "plugins" configuration property which
* should not be set up as an attribute. This property is primarily required so
* that when <a href="#property__allowAdHocAttrs">`_allowAdHocAttrs`</a> is enabled by a class,
* non-attribute configuration properties don't get added as ad-hoc attributes.
*
* @property _NON_ATTRS_CFG
* @type Array
* @static
* @private
*/
BaseCore._NON_ATTRS_CFG = ["plugins"];
/**
* This property controls whether or not instances of this class should
* allow users to add ad-hoc attributes through the constructor configuration
* hash.
*
* AdHoc attributes are attributes which are not defined by the class, and are
* not handled by the MyClass._NON_ATTRS_CFG
*
* @property _allowAdHocAttrs
* @type boolean
* @default undefined (false)
* @protected
*/
/**
* The string to be used to identify instances of this class.
*
* Classes extending BaseCore, should define their own
* static NAME property, which should be camelCase by
* convention (e.g. MyClass.NAME = "myClass";).
*
* @property NAME
* @type String
* @static
*/
BaseCore.NAME = "baseCore";
/**
* 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
* AttributeCore's <a href="AttributeCore.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 ATTRS
* @type Object
* @static
*/
BaseCore.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
}
};
/**
Provides a way to safely modify a `Y.BaseCore` subclass' static `ATTRS`
after the class has been defined or created.
BaseCore-based classes cache information about the class hierarchy in order
to efficiently create instances. This cache includes includes the aggregated
`ATTRS` configs. If the static `ATTRS` configs need to be modified after the
class has been defined or create, then use this method which will make sure
to clear any cached data before making any modifications.
@method modifyAttrs
@param {Function} [ctor] The constructor function whose `ATTRS` should be
modified. If a `ctor` function is not specified, then `this` is assumed
to be the constructor which hosts the `ATTRS`.
@param {Object} configs The collection of `ATTRS` configs to mix with the
existing attribute configurations.
@static
@since 3.10.0
**/
BaseCore.modifyAttrs = function (ctor, configs) {
// When called without a constructor, assume `this` is the constructor.
if (typeof ctor !== 'function') {
configs = ctor;
ctor = this;
}
var attrs, attr, name;
// Eagerly create the `ATTRS` object if it doesn't already exist.
attrs = ctor.ATTRS || (ctor.ATTRS = {});
if (configs) {
// Clear cache because it has ATTRS aggregation data which is about
// to be modified.
ctor._CACHED_CLASS_DATA = null;
for (name in configs) {
if (configs.hasOwnProperty(name)) {
attr = attrs[name] || (attrs[name] = {});
Y.mix(attr, configs[name], true);
}
}
}
};
BaseCore.prototype = {
/**
* Internal construction logic for BaseCore.
*
* @method _initBase
* @param {Object} config The constructor configuration object
* @private
*/
_initBase : function(config) {
Y.log('init called', 'life', 'base');
Y.stamp(this);
this._initAttribute(config);
// 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; }
/**
* The string used to identify the class of this object.
*
* @deprecated Use this.constructor.NAME
* @property name
* @type String
*/
this.name = this.constructor.NAME;
this.init.apply(this, arguments);
},
/**
* Initializes AttributeCore
*
* @method _initAttribute
* @private
*/
_initAttribute: function() {
AttributeCore.call(this);
},
/**
* Init lifecycle method, invoked during construction. Sets up attributes
* and invokes initializers for the class hierarchy.
*
* @method init
* @chainable
* @param {Object} cfg Object with configuration property name/value pairs
* @return {BaseCore} A reference to this object
*/
init: function(cfg) {
Y.log('init called', 'life', 'base');
this._baseInit(cfg);
return this;
},
/**
* Internal initialization implementation for BaseCore
*
* @method _baseInit
* @private
*/
_baseInit: function(cfg) {
this._initHierarchy(cfg);
if (this._initPlugins) {
// Need to initPlugins manually, to handle constructor parsing, static Plug parsing
this._initPlugins(cfg);
}
this._set(INITIALIZED, true);
},
/**
* Destroy lifecycle method. Invokes destructors for the class hierarchy.
*
* @method destroy
* @return {BaseCore} A reference to this object
* @chainable
*/
destroy: function() {
this._baseDestroy();
return this;
},
/**
* Internal destroy implementation for BaseCore
*
* @method _baseDestroy
* @private
*/
_baseDestroy : function() {
if (this._destroyPlugins) {
this._destroyPlugins();
}
this._destroyHierarchy();
this._set(DESTROYED, true);
},
/**
* Returns the class hierarchy for this object, with BaseCore 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 to isolate the attrs config for this instance to pass to `addAttrs`,
* from the static cached ATTRS for the class.
*
* @method _getInstanceAttrCfgs
* @private
*
* @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 to be added for this instance, suitable
* for passing through to `addAttrs`.
*/
_getInstanceAttrCfgs : function(allCfgs) {
var cfgs = {},
cfg,
val,
subAttr,
subAttrs,
subAttrPath,
attr,
attrCfg,
allSubAttrs = allCfgs._subAttrs,
attrCfgProperties = this._attrCfgHash();
for (attr in allCfgs) {
if (allCfgs.hasOwnProperty(attr) && attr !== "_subAttrs") {
attrCfg = allCfgs[attr];
// Need to isolate from allCfgs, because we're going to set values etc.
cfg = cfgs[attr] = _wlmix({}, attrCfg, attrCfgProperties);
val = cfg.value;
if (val && (typeof val === "object")) {
this._cloneDefaultValue(attr, cfg);
}
if (allSubAttrs && allSubAttrs.hasOwnProperty(attr)) {
subAttrs = allCfgs._subAttrs[attr];
for (subAttrPath in subAttrs) {
subAttr = subAttrs[subAttrPath];
if (subAttr.path) {
O.setValue(cfg.value, subAttr.path, subAttr.value);
}
}
}
}
}
return cfgs;
},
/**
* @method _filterAdHocAttrs
* @private
*
* @param {Object} allAttrs 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.
* @param {Object} userVals The config object passed in by the user, from which adhoc attrs are to be filtered.
* @return {Object} The set of adhoc attributes passed in, in the form
* of an object with attribute name/configuration pairs.
*/
_filterAdHocAttrs : function(allAttrs, userVals) {
var adHocs,
nonAttrs = this._nonAttrs,
attr;
if (userVals) {
adHocs = {};
for (attr in userVals) {
if (!allAttrs[attr] && !nonAttrs[attr] && userVals.hasOwnProperty(attr)) {
adHocs[attr] = {
value:userVals[attr]
};
}
}
}
return adHocs;
},
/**
* 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 ctor = this.constructor,
cachedClassData = ctor._CACHED_CLASS_DATA,
c,
i,
l,
attrCfg,
attrCfgHash,
needsAttrCfgHash = !ctor._ATTR_CFG_HASH,
nonAttrsCfg,
nonAttrs = {},
classes = [],
attrs = [];
// Start with `this` instance's constructor.
c = ctor;
if (!cachedClassData) {
while (c) {
// Add to classes
classes[classes.length] = c;
// Add to attributes
if (c.ATTRS) {
attrs[attrs.length] = c.ATTRS;
}
// Aggregate ATTR cfg whitelist.
if (needsAttrCfgHash) {
attrCfg = c._ATTR_CFG;
attrCfgHash = attrCfgHash || {};
if (attrCfg) {
for (i = 0, l = attrCfg.length; i < l; i += 1) {
attrCfgHash[attrCfg[i]] = true;
}
}
}
// Commenting out the if. We always aggregate, since we don't
// know if we'll be needing this on the instance or not.
// if (this._allowAdHocAttrs) {
nonAttrsCfg = c._NON_ATTRS_CFG;
if (nonAttrsCfg) {
for (i = 0, l = nonAttrsCfg.length; i < l; i++) {
nonAttrs[nonAttrsCfg[i]] = true;
}
}
//}
c = c.superclass ? c.superclass.constructor : null;
}
// Cache computed `_ATTR_CFG_HASH` on the constructor.
if (needsAttrCfgHash) {
ctor._ATTR_CFG_HASH = attrCfgHash;
}
cachedClassData = ctor._CACHED_CLASS_DATA = {
classes : classes,
nonAttrs : nonAttrs,
attrs : this._aggregateAttrs(attrs)
};
}
this._classes = cachedClassData.classes;
this._attrs = cachedClassData.attrs;
this._nonAttrs = cachedClassData.nonAttrs;
},
/**
* Utility method to define the attribute hash used to filter/whitelist property mixes for
* this class for iteration performance reasons.
*
* @method _attrCfgHash
* @private
*/
_attrCfgHash: function() {
return this.constructor._ATTR_CFG_HASH;
},
/**
* 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.
*
* @method _cloneDefaultValue
* @param {Object} cfg
* @private
*/
_cloneDefaultValue : function(attr, cfg) {
var val = cfg.value,
clone = cfg.cloneDefaultValue;
if (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 === undefined && (OBJECT_CONSTRUCTOR === val.constructor || L.isArray(val)))) {
cfg.value = Y.clone(val);
}
// else if (clone === false), don't clone the static default value.
// It's intended to be used by reference.
},
/**
* 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).
*
* @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,
subAttrsHash,
cfg,
path,
i,
cfgPropsHash = this._attrCfgHash(),
aggAttr,
aggAttrs = {};
if (allAttrs) {
for (i = allAttrs.length-1; i >= 0; --i) {
attrs = allAttrs[i];
for (attr in attrs) {
if (attrs.hasOwnProperty(attr)) {
// PERF TODO: Do we need to merge here, since we're merging later in getInstanceAttrCfgs
// Should we move this down to only merge if we hit the path or valueFn ifs below?
cfg = _wlmix({}, attrs[attr], cfgPropsHash);
path = null;
if (attr.indexOf(DOT) !== -1) {
path = attr.split(DOT);
attr = path.shift();
}
aggAttr = aggAttrs[attr];
if (path && aggAttr && aggAttr.value) {
subAttrsHash = aggAttrs._subAttrs;
if (!subAttrsHash) {
subAttrsHash = aggAttrs._subAttrs = {};
}
if (!subAttrsHash[attr]) {
subAttrsHash[attr] = {};
}
subAttrsHash[attr][path.join(DOT)] = {
value: cfg.value,
path : path
};
} else if (!path) {
if (!aggAttr) {
aggAttrs[attr] = cfg;
} else {
if (aggAttr.valueFn && VALUE in cfg) {
aggAttr.valueFn = null;
}
// Mix into existing config.
_wlmix(aggAttr, cfg, cfgPropsHash);
}
}
}
}
}
}
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_BaseCore.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,
i,
l,
ci,
ei,
el,
ext,
extProto,
exts,
instanceAttrs,
initializers = [],
classes = this._getClasses(),
attrCfgs = this._getAttrCfgs(),
cl = classes.length - 1;
// Constructors
for (ci = cl; ci >= 0; ci--) {
constr = classes[ci];
constrProto = constr.prototype;
exts = constr._yuibuild && constr._yuibuild.exts;
// Using INITIALIZER in hasOwnProperty check, for performance reasons (helps IE6 avoid GC thresholds when
// referencing string literals). Not using it in apply, again, for performance "." is faster.
if (constrProto.hasOwnProperty(INITIALIZER)) {
// Store initializer while we're here and looping
initializers[initializers.length] = constrProto.initializer;
}
if (exts) {
for (ei = 0, el = exts.length; ei < el; ei++) {
ext = exts[ei];
// Ext Constructor
ext.apply(this, arguments);
extProto = ext.prototype;
if (extProto.hasOwnProperty(INITIALIZER)) {
// Store initializer while we're here and looping
initializers[initializers.length] = extProto.initializer;
}
}
}
}
// ATTRS
instanceAttrs = this._getInstanceAttrCfgs(attrCfgs);
if (this._preAddAttrs) {
this._preAddAttrs(instanceAttrs, userVals, lazy);
}
if (this._allowAdHocAttrs) {
this.addAttrs(this._filterAdHocAttrs(attrCfgs, userVals), userVals, lazy);
}
this.addAttrs(instanceAttrs, userVals, lazy);
// Initializers
for (i = 0, l = initializers.length; i < l; i++) {
initializers[i].apply(this, arguments);
}
},
/**
* Destroys the class hierarchy for this instance by invoking
* the destructor method on the prototype of each class in the hierarchy.
*
* @method _destroyHierarchy
* @private
*/
_destroyHierarchy : function() {
var constr,
constrProto,
ci, cl, ei, el, exts, extProto,
classes = this._getClasses();
for (ci = 0, cl = classes.length; ci < cl; ci++) {
constr = classes[ci];
constrProto = constr.prototype;
exts = constr._yuibuild && constr._yuibuild.exts;
if (exts) {
for (ei = 0, el = exts.length; ei < el; ei++) {
extProto = exts[ei].prototype;
if (extProto.hasOwnProperty(DESTRUCTOR)) {
extProto.destructor.apply(this, arguments);
}
}
}
if (constrProto.hasOwnProperty(DESTRUCTOR)) {
constrProto.destructor.apply(this, arguments);
}
}
},
/**
* Default toString implementation. Provides the constructor NAME
* and the instance guid, if set.
*
* @method toString
* @return {String} String representation for this object
*/
toString: function() {
return this.name + "[" + Y.stamp(this, true) + "]";
}
};
// Straightup augment, no wrapper functions
Y.mix(BaseCore, AttributeCore, false, null, 1);
// Fix constructor
BaseCore.prototype.constructor = BaseCore;
Y.BaseCore = BaseCore;