Upgrade to ExtJS 4.0.0 - Released 04/26/2011
[extjs.git] / src / core / src / class / Class.js
diff --git a/src/core/src/class/Class.js b/src/core/src/class/Class.js
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+/**
+ * @author Jacky Nguyen <jacky@sencha.com>
+ * @docauthor Jacky Nguyen <jacky@sencha.com>
+ * @class Ext.Class
+ * 
+ * Handles class creation throughout the whole framework. Note that most of the time {@link Ext#define Ext.define} should
+ * be used instead, since it's a higher level wrapper that aliases to {@link Ext.ClassManager#create}
+ * to enable namespacing and dynamic dependency resolution.
+ * 
+ * # Basic syntax: #
+ * 
+ *     Ext.define(className, properties);
+ * 
+ * in which `properties` is an object represent a collection of properties that apply to the class. See
+ * {@link Ext.ClassManager#create} for more detailed instructions.
+ * 
+ *     Ext.define('Person', {
+ *          name: 'Unknown',
+ * 
+ *          constructor: function(name) {
+ *              if (name) {
+ *                  this.name = name;
+ *              }
+ * 
+ *              return this;
+ *          },
+ * 
+ *          eat: function(foodType) {
+ *              alert("I'm eating: " + foodType);
+ * 
+ *              return this;
+ *          }
+ *     });
+ * 
+ *     var aaron = new Person("Aaron");
+ *     aaron.eat("Sandwich"); // alert("I'm eating: Sandwich");
+ * 
+ * Ext.Class has a powerful set of extensible {@link Ext.Class#registerPreprocessor pre-processors} which takes care of
+ * everything related to class creation, including but not limited to inheritance, mixins, configuration, statics, etc.
+ * 
+ * # Inheritance: #
+ * 
+ *     Ext.define('Developer', {
+ *          extend: 'Person',
+ * 
+ *          constructor: function(name, isGeek) {
+ *              this.isGeek = isGeek;
+ * 
+ *              // Apply a method from the parent class' prototype
+ *              this.callParent([name]);
+ * 
+ *              return this;
+ * 
+ *          },
+ * 
+ *          code: function(language) {
+ *              alert("I'm coding in: " + language);
+ * 
+ *              this.eat("Bugs");
+ * 
+ *              return this;
+ *          }
+ *     });
+ * 
+ *     var jacky = new Developer("Jacky", true);
+ *     jacky.code("JavaScript"); // alert("I'm coding in: JavaScript");
+ *                               // alert("I'm eating: Bugs");
+ * 
+ * See {@link Ext.Base#callParent} for more details on calling superclass' methods
+ * 
+ * # Mixins: #
+ * 
+ *     Ext.define('CanPlayGuitar', {
+ *          playGuitar: function() {
+ *             alert("F#...G...D...A");
+ *          }
+ *     });
+ * 
+ *     Ext.define('CanComposeSongs', {
+ *          composeSongs: function() { ... }
+ *     });
+ * 
+ *     Ext.define('CanSing', {
+ *          sing: function() {
+ *              alert("I'm on the highway to hell...")
+ *          }
+ *     });
+ * 
+ *     Ext.define('Musician', {
+ *          extend: 'Person',
+ * 
+ *          mixins: {
+ *              canPlayGuitar: 'CanPlayGuitar',
+ *              canComposeSongs: 'CanComposeSongs',
+ *              canSing: 'CanSing'
+ *          }
+ *     })
+ * 
+ *     Ext.define('CoolPerson', {
+ *          extend: 'Person',
+ * 
+ *          mixins: {
+ *              canPlayGuitar: 'CanPlayGuitar',
+ *              canSing: 'CanSing'
+ *          },
+ * 
+ *          sing: function() {
+ *              alert("Ahem....");
+ * 
+ *              this.mixins.canSing.sing.call(this);
+ * 
+ *              alert("[Playing guitar at the same time...]");
+ * 
+ *              this.playGuitar();
+ *          }
+ *     });
+ * 
+ *     var me = new CoolPerson("Jacky");
+ * 
+ *     me.sing(); // alert("Ahem...");
+ *                // alert("I'm on the highway to hell...");
+ *                // alert("[Playing guitar at the same time...]");
+ *                // alert("F#...G...D...A");
+ * 
+ * # Config: #
+ * 
+ *     Ext.define('SmartPhone', {
+ *          config: {
+ *              hasTouchScreen: false,
+ *              operatingSystem: 'Other',
+ *              price: 500
+ *          },
+ * 
+ *          isExpensive: false,
+ * 
+ *          constructor: function(config) {
+ *              this.initConfig(config);
+ * 
+ *              return this;
+ *          },
+ * 
+ *          applyPrice: function(price) {
+ *              this.isExpensive = (price > 500);
+ * 
+ *              return price;
+ *          },
+ * 
+ *          applyOperatingSystem: function(operatingSystem) {
+ *              if (!(/^(iOS|Android|BlackBerry)$/i).test(operatingSystem)) {
+ *                  return 'Other';
+ *              }
+ * 
+ *              return operatingSystem;
+ *          }
+ *     });
+ * 
+ *     var iPhone = new SmartPhone({
+ *          hasTouchScreen: true,
+ *          operatingSystem: 'iOS'
+ *     });
+ * 
+ *     iPhone.getPrice(); // 500;
+ *     iPhone.getOperatingSystem(); // 'iOS'
+ *     iPhone.getHasTouchScreen(); // true;
+ *     iPhone.hasTouchScreen(); // true
+ * 
+ *     iPhone.isExpensive; // false;
+ *     iPhone.setPrice(600);
+ *     iPhone.getPrice(); // 600
+ *     iPhone.isExpensive; // true;
+ * 
+ *     iPhone.setOperatingSystem('AlienOS');
+ *     iPhone.getOperatingSystem(); // 'Other'
+ * 
+ * # Statics: #
+ * 
+ *     Ext.define('Computer', {
+ *          statics: {
+ *              factory: function(brand) {
+ *                 // 'this' in static methods refer to the class itself
+ *                  return new this(brand);
+ *              }
+ *          },
+ * 
+ *          constructor: function() { ... }
+ *     });
+ * 
+ *     var dellComputer = Computer.factory('Dell');
+ * 
+ * Also see {@link Ext.Base#statics} and {@link Ext.Base#self} for more details on accessing
+ * static properties within class methods
+ *
+ */
+(function() {
+
+    var Class,
+        Base = Ext.Base,
+        baseStaticProperties = [],
+        baseStaticProperty;
+
+    for (baseStaticProperty in Base) {
+        if (Base.hasOwnProperty(baseStaticProperty)) {
+            baseStaticProperties.push(baseStaticProperty);
+        }
+    }
+
+    /**
+     * @constructor
+     * @param {Object} classData An object represent the properties of this class
+     * @param {Function} createdFn Optional, the callback function to be executed when this class is fully created.
+     * Note that the creation process can be asynchronous depending on the pre-processors used.
+     * @return {Ext.Base} The newly created class
+     */
+    Ext.Class = Class = function(newClass, classData, onClassCreated) {
+        if (typeof newClass !== 'function') {
+            onClassCreated = classData;
+            classData = newClass;
+            newClass = function() {
+                return this.constructor.apply(this, arguments);
+            };
+        }
+
+        if (!classData) {
+            classData = {};
+        }
+
+        var preprocessorStack = classData.preprocessors || Class.getDefaultPreprocessors(),
+            registeredPreprocessors = Class.getPreprocessors(),
+            index = 0,
+            preprocessors = [],
+            preprocessor, preprocessors, staticPropertyName, process, i, j, ln;
+
+        for (i = 0, ln = baseStaticProperties.length; i < ln; i++) {
+            staticPropertyName = baseStaticProperties[i];
+            newClass[staticPropertyName] = Base[staticPropertyName];
+        }
+
+        delete classData.preprocessors;
+
+        for (j = 0, ln = preprocessorStack.length; j < ln; j++) {
+            preprocessor = preprocessorStack[j];
+
+            if (typeof preprocessor === 'string') {
+                preprocessor = registeredPreprocessors[preprocessor];
+
+                if (!preprocessor.always) {
+                    if (classData.hasOwnProperty(preprocessor.name)) {
+                        preprocessors.push(preprocessor.fn);
+                    }
+                }
+                else {
+                    preprocessors.push(preprocessor.fn);
+                }
+            }
+            else {
+                preprocessors.push(preprocessor);
+            }
+        }
+
+        classData.onClassCreated = onClassCreated;
+
+        classData.onBeforeClassCreated = function(cls, data) {
+            onClassCreated = data.onClassCreated;
+
+            delete data.onBeforeClassCreated;
+            delete data.onClassCreated;
+
+            cls.implement(data);
+
+            if (onClassCreated) {
+                onClassCreated.call(cls, cls);
+            }
+        };
+
+        process = function(cls, data) {
+            preprocessor = preprocessors[index++];
+
+            if (!preprocessor) {
+                data.onBeforeClassCreated.apply(this, arguments);
+                return;
+            }
+
+            if (preprocessor.call(this, cls, data, process) !== false) {
+                process.apply(this, arguments);
+            }
+        };
+
+        process.call(Class, newClass, classData);
+
+        return newClass;
+    };
+
+    Ext.apply(Class, {
+
+        /** @private */
+        preprocessors: {},
+
+        /**
+         * Register a new pre-processor to be used during the class creation process
+         *
+         * @member Ext.Class registerPreprocessor
+         * @param {String} name The pre-processor's name
+         * @param {Function} fn The callback function to be executed. Typical format:
+
+    function(cls, data, fn) {
+        // Your code here
+
+        // Execute this when the processing is finished.
+        // Asynchronous processing is perfectly ok
+        if (fn) {
+            fn.call(this, cls, data);
+        }
+    });
+
+         * Passed arguments for this function are:
+         *
+         * - `{Function} cls`: The created class
+         * - `{Object} data`: The set of properties passed in {@link Ext.Class} constructor
+         * - `{Function} fn`: The callback function that <b>must</b> to be executed when this pre-processor finishes,
+         * regardless of whether the processing is synchronous or aynchronous
+         *
+         * @return {Ext.Class} this
+         * @markdown
+         */
+        registerPreprocessor: function(name, fn, always) {
+            this.preprocessors[name] = {
+                name: name,
+                always: always ||  false,
+                fn: fn
+            };
+
+            return this;
+        },
+
+        /**
+         * Retrieve a pre-processor callback function by its name, which has been registered before
+         *
+         * @param {String} name
+         * @return {Function} preprocessor
+         */
+        getPreprocessor: function(name) {
+            return this.preprocessors[name];
+        },
+
+        getPreprocessors: function() {
+            return this.preprocessors;
+        },
+
+        /**
+         * Retrieve the array stack of default pre-processors
+         *
+         * @return {Function} defaultPreprocessors
+         */
+        getDefaultPreprocessors: function() {
+            return this.defaultPreprocessors || [];
+        },
+
+        /**
+         * Set the default array stack of default pre-processors
+         *
+         * @param {Array} preprocessors
+         * @return {Ext.Class} this
+         */
+        setDefaultPreprocessors: function(preprocessors) {
+            this.defaultPreprocessors = Ext.Array.from(preprocessors);
+
+            return this;
+        },
+
+        /**
+         * Insert this pre-processor at a specific position in the stack, optionally relative to
+         * any existing pre-processor. For example:
+
+    Ext.Class.registerPreprocessor('debug', function(cls, data, fn) {
+        // Your code here
+
+        if (fn) {
+            fn.call(this, cls, data);
+        }
+    }).insertDefaultPreprocessor('debug', 'last');
+
+         * @param {String} name The pre-processor name. Note that it needs to be registered with
+         * {@link Ext#registerPreprocessor registerPreprocessor} before this
+         * @param {String} offset The insertion position. Four possible values are:
+         * 'first', 'last', or: 'before', 'after' (relative to the name provided in the third argument)
+         * @param {String} relativeName
+         * @return {Ext.Class} this
+         * @markdown
+         */
+        setDefaultPreprocessorPosition: function(name, offset, relativeName) {
+            var defaultPreprocessors = this.defaultPreprocessors,
+                index;
+
+            if (typeof offset === 'string') {
+                if (offset === 'first') {
+                    defaultPreprocessors.unshift(name);
+
+                    return this;
+                }
+                else if (offset === 'last') {
+                    defaultPreprocessors.push(name);
+
+                    return this;
+                }
+
+                offset = (offset === 'after') ? 1 : -1;
+            }
+
+            index = Ext.Array.indexOf(defaultPreprocessors, relativeName);
+
+            if (index !== -1) {
+                defaultPreprocessors.splice(Math.max(0, index + offset), 0, name);
+            }
+
+            return this;
+        }
+    });
+
+    Class.registerPreprocessor('extend', function(cls, data) {
+        var extend = data.extend,
+            base = Ext.Base,
+            basePrototype = base.prototype,
+            prototype = function() {},
+            parent, i, k, ln, staticName, parentStatics,
+            parentPrototype, clsPrototype;
+
+        if (extend && extend !== Object) {
+            parent = extend;
+        }
+        else {
+            parent = base;
+        }
+
+        parentPrototype = parent.prototype;
+
+        prototype.prototype = parentPrototype;
+        clsPrototype = cls.prototype = new prototype();
+
+        if (!('$class' in parent)) {
+            for (i in basePrototype) {
+                if (!parentPrototype[i]) {
+                    parentPrototype[i] = basePrototype[i];
+                }
+            }
+        }
+
+        clsPrototype.self = cls;
+
+        cls.superclass = clsPrototype.superclass = parentPrototype;
+
+        delete data.extend;
+
+        // Statics inheritance
+        parentStatics = parentPrototype.$inheritableStatics;
+
+        if (parentStatics) {
+            for (k = 0, ln = parentStatics.length; k < ln; k++) {
+                staticName = parentStatics[k];
+
+                if (!cls.hasOwnProperty(staticName)) {
+                    cls[staticName] = parent[staticName];
+                }
+            }
+        }
+
+        // Merge the parent class' config object without referencing it
+        if (parentPrototype.config) {
+            clsPrototype.config = Ext.Object.merge({}, parentPrototype.config);
+        }
+        else {
+            clsPrototype.config = {};
+        }
+
+        if (clsPrototype.$onExtended) {
+            clsPrototype.$onExtended.call(cls, cls, data);
+        }
+
+        if (data.onClassExtended) {
+            clsPrototype.$onExtended = data.onClassExtended;
+            delete data.onClassExtended;
+        }
+
+    }, true);
+
+    Class.registerPreprocessor('statics', function(cls, data) {
+        var statics = data.statics,
+            name;
+
+        for (name in statics) {
+            if (statics.hasOwnProperty(name)) {
+                cls[name] = statics[name];
+            }
+        }
+
+        delete data.statics;
+    });
+
+    Class.registerPreprocessor('inheritableStatics', function(cls, data) {
+        var statics = data.inheritableStatics,
+            inheritableStatics,
+            prototype = cls.prototype,
+            name;
+
+        inheritableStatics = prototype.$inheritableStatics;
+
+        if (!inheritableStatics) {
+            inheritableStatics = prototype.$inheritableStatics = [];
+        }
+
+        for (name in statics) {
+            if (statics.hasOwnProperty(name)) {
+                cls[name] = statics[name];
+                inheritableStatics.push(name);
+            }
+        }
+
+        delete data.inheritableStatics;
+    });
+
+    Class.registerPreprocessor('mixins', function(cls, data) {
+        cls.mixin(data.mixins);
+
+        delete data.mixins;
+    });
+
+    Class.registerPreprocessor('config', function(cls, data) {
+        var prototype = cls.prototype;
+
+        Ext.Object.each(data.config, function(name) {
+            var cName = name.charAt(0).toUpperCase() + name.substr(1),
+                pName = name,
+                apply = 'apply' + cName,
+                setter = 'set' + cName,
+                getter = 'get' + cName;
+
+            if (!(apply in prototype) && !data.hasOwnProperty(apply)) {
+                data[apply] = function(val) {
+                    return val;
+                };
+            }
+
+            if (!(setter in prototype) && !data.hasOwnProperty(setter)) {
+                data[setter] = function(val) {
+                    var ret = this[apply].call(this, val, this[pName]);
+
+                    if (ret !== undefined) {
+                        this[pName] = ret;
+                    }
+
+                    return this;
+                };
+            }
+
+            if (!(getter in prototype) && !data.hasOwnProperty(getter)) {
+                data[getter] = function() {
+                    return this[pName];
+                };
+            }
+        });
+
+        Ext.Object.merge(prototype.config, data.config);
+        delete data.config;
+    });
+
+    Class.setDefaultPreprocessors(['extend', 'statics', 'inheritableStatics', 'mixins', 'config']);
+
+    // Backwards compatible
+    Ext.extend = function(subclass, superclass, members) {
+        if (arguments.length === 2 && Ext.isObject(superclass)) {
+            members = superclass;
+            superclass = subclass;
+            subclass = null;
+        }
+
+        var cls;
+
+        if (!superclass) {
+            Ext.Error.raise("Attempting to extend from a class which has not been loaded on the page.");
+        }
+
+        members.extend = superclass;
+        members.preprocessors = ['extend', 'mixins', 'config', 'statics'];
+
+        if (subclass) {
+            cls = new Class(subclass, members);
+        }
+        else {
+            cls = new Class(members);
+        }
+
+        cls.prototype.override = function(o) {
+            for (var m in o) {
+                if (o.hasOwnProperty(m)) {
+                    this[m] = o[m];
+                }
+            }
+        };
+
+        return cls;
+    };
+
+})();