Admin: 1 версия

2010-05-26T08:24:19Z

1 версия

в 18:52, 25 мая 2010

2010-05-25T18:52:56Z

Новая страница

== Using inheritFrom method from zInherit Library==



<source lang="javascript">
<html>
<head>
<title>Example</title>
<script type="text/javascript">
/*------------------------------------------------------------------------------
* JavaScript zInherit Library
* Version 1.0
* by Nicholas C. Zakas, http://www.nczonline.net/
* Copyright (c) 2004-2005 Nicholas C. Zakas. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*------------------------------------------------------------------------------
*/

/**
* Inherits properties and methods from the given class.
* @scope public
* @param fnClass The constructor function to inherit from.
*/
Object.prototype.inheritFrom = function (fnClass /*: Function */) /*:void*/ {
/**
* Inherits all classes going up the inheritance chain recursively.
* @param fnClass The class to inherit from.
* @param arrClasses The array of classes to build up.
* @scope private
*/
function inheritClasses(fnClass /*:Function*/,
arrClasses /*:Array*/) /*:void*/ {

arrClasses.push(fnClass);
if (typeof fnClass.__superclasses__ == "object") {
for (var i=0; i < fnClass.__superclasses__.length; i++){
inheritClasses(fnClass.__superclasses__[i], arrClasses);
}
}
}

if (typeof this.constructor.__superclasses__ == "undefined") {
this.constructor.__superclasses__ = new Array();
}

inheritClasses(fnClass, this.constructor.__superclasses__);

for (prop in fnClass.prototype) {
if (typeof fnClass.prototype[prop] == "function") {
this[prop] = fnClass.prototype[prop];
}
}
};
/**
* Determines if the given object is an instance of a given class.
* This method is necessary because using {@link #inheritFrom} renders
* the JavaScript <code>instanceof</code> operator useless.
* @param fnClass The constructor function to test.
* @return True if the object is an instance of the class, false if not.
* @scope public
*/
Object.prototype.instanceOf = function (fnClass /*:Function*/) /*: boolean */ {
if (this.constructor == fnClass) {
return true;
} else if (typeof this.constructor.__superclasses__ == "object") {
for (var i=0; i < this.constructor.__superclasses__.length; i++) {
if (this.constructor.__superclasses__[i] == fnClass) {
return true;
}
}
return false;
} else {
return false;
}
};
</script>
</head>
<body>
<script type="text/javascript">
function ClassX() {
this.messageX = "This is the X message.";
if (typeof ClassX._initialized == "undefined") {

ClassX.prototype.sayMessageX = function () {
alert(this.messageX);
};
ClassX._initialized = true;
}
}
function ClassY() {
this.messageY = "This is the Y message.";
if (typeof ClassY._initialized == "undefined") {

ClassY.prototype.sayMessageY = function () {
alert(this.messageY);
};
ClassY._initialized = true;
}
}
function ClassZ() {
ClassX.apply(this);
ClassY.apply(this);
this.messageZ = "This is the Z message.";
if (typeof ClassZ._initialized == "undefined") {

ClassZ.prototype.inheritFrom(ClassX);
ClassZ.prototype.inheritFrom(ClassY);
ClassZ.prototype.sayMessageZ = function () {
alert(this.messageZ);
};
ClassZ._initialized = true;
}
}
var objZ = new ClassZ();
objZ.sayMessageX();
objZ.sayMessageY();
objZ.sayMessageZ();
</script>

</body>
</html></source>

== Using instanceOf method from zInherit Library==



<source lang="javascript">
<html>
<head>
<title>Example</title>
<script type="text/javascript">
/*------------------------------------------------------------------------------
* JavaScript zInherit Library
* Version 1.0
* by Nicholas C. Zakas, http://www.nczonline.net/
* Copyright (c) 2004-2005 Nicholas C. Zakas. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*------------------------------------------------------------------------------
*/

/**
* Inherits properties and methods from the given class.
* @scope public
* @param fnClass The constructor function to inherit from.
*/
Object.prototype.inheritFrom = function (fnClass /*: Function */) /*:void*/ {
/**
* Inherits all classes going up the inheritance chain recursively.
* @param fnClass The class to inherit from.
* @param arrClasses The array of classes to build up.
* @scope private
*/
function inheritClasses(fnClass /*:Function*/,
arrClasses /*:Array*/) /*:void*/ {

arrClasses.push(fnClass);
if (typeof fnClass.__superclasses__ == "object") {
for (var i=0; i < fnClass.__superclasses__.length; i++){
inheritClasses(fnClass.__superclasses__[i], arrClasses);
}
}
}

if (typeof this.constructor.__superclasses__ == "undefined") {
this.constructor.__superclasses__ = new Array();
}

inheritClasses(fnClass, this.constructor.__superclasses__);

for (prop in fnClass.prototype) {
if (typeof fnClass.prototype[prop] == "function") {
this[prop] = fnClass.prototype[prop];
}
}
};
/**
* Determines if the given object is an instance of a given class.
* This method is necessary because using {@link #inheritFrom} renders
* the JavaScript <code>instanceof</code> operator useless.
* @param fnClass The constructor function to test.
* @return True if the object is an instance of the class, false if not.
* @scope public
*/
Object.prototype.instanceOf = function (fnClass /*:Function*/) /*: boolean */ {
if (this.constructor == fnClass) {
return true;
} else if (typeof this.constructor.__superclasses__ == "object") {
for (var i=0; i < this.constructor.__superclasses__.length; i++) {
if (this.constructor.__superclasses__[i] == fnClass) {
return true;
}
}
return false;
} else {
return false;
}
};
</script>
</head>
<body>
<script type="text/javascript">
function Shape(iSides) {
this.sides = iSides;

if (typeof Shape._initialized == "undefined") {
Shape.prototype.getArea = function () {
return 0;
};

Shape._initialized = true;
}
}
function Triangle(iBase, iHeight) {
Shape.call(this, 3);
this.base = iBase;
this.height = iHeight;

if (typeof Triangle._initialized == "undefined") {

Triangle.prototype.inheritFrom(Shape);
Triangle.prototype.getArea = function () {
return 0.5 * this.base * this.height;
};

Triangle._initialized = true;
}
}
function Rectangle(iLength, iWidth) {
Shape.call(this, 4);
this.length = iLength;
this.width = iWidth;

if (typeof Rectangle._initialized == "undefined") {

Rectangle.prototype.inheritFrom(Shape);
Rectangle.prototype.getArea = function () {
return this.length * this.width;
};

Rectangle._initialized = true;
}
}

var triangle = new Triangle(12, 4);
var rectangle = new Rectangle(22, 10);
alert(triangle.sides);
alert(triangle.getArea());
alert(rectangle.sides);
alert(rectangle.getArea());
alert(triangle.instanceOf(Triangle));
alert(triangle.instanceOf(Shape));
alert(rectangle.instanceOf(Rectangle));
alert(rectangle.instanceOf(Shape));
</script>

</body>
</html></source>

== Using zInherit Library to build class inheritance==

<p>The zInherit library adds two methods to the Object class: inheritFrom() and instanceOf().</p>
<p>The following line uses prototype chaining to inherit methods from BaseClass to SubClass:</p>



<source lang="javascript">
SubClass.prototype = new BaseClass();</source>

== Using zInherit Library to build class inheritance in three levels==



<source lang="javascript">
<html>
<head>
<title>Example</title>
<script type="text/javascript">
/*------------------------------------------------------------------------------
* JavaScript zInherit Library
* Version 1.0
* by Nicholas C. Zakas, http://www.nczonline.net/
* Copyright (c) 2004-2005 Nicholas C. Zakas. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*------------------------------------------------------------------------------
*/

/**
* Inherits properties and methods from the given class.
* @scope public
* @param fnClass The constructor function to inherit from.
*/
Object.prototype.inheritFrom = function (fnClass /*: Function */) /*:void*/ {
/**
* Inherits all classes going up the inheritance chain recursively.
* @param fnClass The class to inherit from.
* @param arrClasses The array of classes to build up.
* @scope private
*/
function inheritClasses(fnClass /*:Function*/,
arrClasses /*:Array*/) /*:void*/ {

arrClasses.push(fnClass);
if (typeof fnClass.__superclasses__ == "object") {
for (var i=0; i < fnClass.__superclasses__.length; i++){
inheritClasses(fnClass.__superclasses__[i], arrClasses);
}
}
}

if (typeof this.constructor.__superclasses__ == "undefined") {
this.constructor.__superclasses__ = new Array();
}

inheritClasses(fnClass, this.constructor.__superclasses__);

for (prop in fnClass.prototype) {
if (typeof fnClass.prototype[prop] == "function") {
this[prop] = fnClass.prototype[prop];
}
}
};
/**
* Determines if the given object is an instance of a given class.
* This method is necessary because using {@link #inheritFrom} renders
* the JavaScript <code>instanceof</code> operator useless.
* @param fnClass The constructor function to test.
* @return True if the object is an instance of the class, false if not.
* @scope public
*/
Object.prototype.instanceOf = function (fnClass /*:Function*/) /*: boolean */ {
if (this.constructor == fnClass) {
return true;
} else if (typeof this.constructor.__superclasses__ == "object") {
for (var i=0; i < this.constructor.__superclasses__.length; i++) {
if (this.constructor.__superclasses__[i] == fnClass) {
return true;
}
}
return false;
} else {
return false;
}
};
</script>
</head>
<body>
<script type="text/javascript">

function Shape(iSides) {
this.sides = iSides;
}
Shape.prototype.getArea = function () {
return 0;
};
function Triangle(iBase, iHeight) {
Shape.call(this, 3);
this.base = iBase;
this.height = iHeight;
}
Triangle.prototype.inheritFrom(Shape);
Triangle.prototype.getArea = function () {
return 0.5 * this.base * this.height;
};
function Rectangle(iLength, iWidth) {
Shape.call(this, 4);
this.length = iLength;
this.width = iWidth;
}
Rectangle.prototype.inheritFrom(Shape);
Rectangle.prototype.getArea = function () {
return this.length * this.width;
};
var triangle = new Triangle(12, 4);
var rectangle = new Rectangle(22, 10);
alert(triangle.sides);
alert(triangle.getArea());
alert(rectangle.sides);
alert(rectangle.getArea());
alert(triangle.instanceOf(Triangle));
alert(triangle.instanceOf(Shape));
alert(rectangle.instanceOf(Rectangle));
alert(rectangle.instanceOf(Shape));
</script>

</body>
</html></source>

← Предыдущая	Версия 08:24, 26 мая 2010
(нет различий)

JavaScript Tutorial/Object Oriented/zInherit - История изменений

Admin: 1 версия

в 18:52, 25 мая 2010