JS扩展类，克隆对象与混合类实例分析

本文实例讲述了JS扩展类，克隆对象与混合类。分享给大家供大家参考，具体如下：

1.类扩展

/* EditInPlaceField类 */
/* 扩展函数 */
function extend(subClass, superClass) {
 var F = function() {};
 F.prototype = superClass.prototype;
 subClass.prototype = new F();
 subClass.prototype.constructor = subClass;
 subClass.superclass = superClass.prototype;
 if(superClass.prototype.constructor == Object.prototype.constructor) {
  superClass.prototype.constructor = superClass;
 }
}
function EditInPlaceField(id, parent, value) { // 构造函数
 this.id = id;
 this.value = value || 'default value';
 this.parentElement = parent;
 this.createElements(this.id);
 this.attachEvents();
};
EditInPlaceField.prototype = {
 createElements: function(id) {
  this.containerElement = document.createElement('div');
  this.parentElement.appendChild(this.containerElement);
  this.staticElement = document.createElement('span');
  this.containerElement.appendChild(this.staticElement);
  this.staticElement.innerHTML = this.value;
  this.fieldElement = document.createElement('input');
  this.fieldElement.type = 'text';
  this.fieldElement.value = this.value;
  this.containerElement.appendChild(this.fieldElement);
  this.saveButton = document.createElement('input');
  this.saveButton.type = 'button';
  this.saveButton.value = 'Save';
  this.containerElement.appendChild(this.saveButton);
  this.cancelButton = document.createElement('input');
  this.cancelButton.type = 'button';
  this.cancelButton.value = 'Cancel';
  this.containerElement.appendChild(this.cancelButton);
  this.convertToText();
 },
 attachEvents: function() {
  var that = this;
  addEvent(this.staticElement, 'click', function() { that.convertToEditable(); });
  addEvent(this.saveButton, 'click', function() { that.save(); });
  addEvent(this.cancelButton, 'click', function() { that.cancel(); });
 },
 convertToEditable: function() {
  this.staticElement.style.display = 'none';
  this.fieldElement.style.display = 'inline';
  this.saveButton.style.display = 'inline';
  this.cancelButton.style.display = 'inline';
  this.setValue(this.value);
 },
 save: function() {
  this.value = this.getValue();
  var that = this;
  var callback = {
   success: function() { that.convertToText(); },
   failure: function() { alert('Error saving value.'); }
  };
  ajaxRequest('GET', 'save.php?id=' + this.id + '&value=' + this.value, callback);
 },
 cancel: function() {
  this.convertToText();
 },
 convertToText: function() {
  this.fieldElement.style.display = 'none';
  this.saveButton.style.display = 'none';
  this.cancelButton.style.display = 'none';
  this.staticElement.style.display = 'inline';
  this.setValue(this.value);
 },
 setValue: function(value) {
  this.fieldElement.value = value;
  this.staticElement.innerHTML = value;
 },
 getValue: function() {
  return this.fieldElement.value;
 }
};
var titleClassical = new EditInPlaceField('titleClassical', $('doc'), 'Title Here');
var currentTitleText = titleClassical.getValue();
/* EditInPlaceArea类 */
function EditInPlaceArea(id, parent, value) {
 EditInPlaceArea.superclass.constructor.call(this, id, parent, value);
};
extend(EditInPlaceArea, EditInPlaceField);
// Override certain methods.
EditInPlaceArea.prototype.createElements = function(id) {
 this.containerElement = document.createElement('div');
 this.parentElement.appendChild(this.containerElement);
 this.staticElement = document.createElement('p');
 this.containerElement.appendChild(this.staticElement);
 this.staticElement.innerHTML = this.value;
 this.fieldElement = document.createElement('textarea');
 this.fieldElement.value = this.value;
 this.containerElement.appendChild(this.fieldElement);
 this.saveButton = document.createElement('input');
 this.saveButton.type = 'button';
 this.saveButton.value = 'Save';
 this.containerElement.appendChild(this.saveButton);
 this.cancelButton = document.createElement('input');
 this.cancelButton.type = 'button';
 this.cancelButton.value = 'Cancel';
 this.containerElement.appendChild(this.cancelButton);
 this.convertToText();
};
EditInPlaceArea.prototype.convertToEditable = function() {
 this.staticElement.style.display = 'none';
 this.fieldElement.style.display = 'block';
 this.saveButton.style.display = 'inline';
 this.cancelButton.style.display = 'inline';
 this.setValue(this.value);
};
EditInPlaceArea.prototype.convertToText = function() {
 this.fieldElement.style.display = 'none';
 this.saveButton.style.display = 'none';
 this.cancelButton.style.display = 'none';
 this.staticElement.style.display = 'block';
 this.setValue(this.value);
};

2.对象克隆

/* EditInPlaceField对象*/
/* 克隆函数 */
function clone(object) {
  function F() {}
  F.prototype = object;
  return new F;
}
var EditInPlaceField = {
 configure: function(id, parent, value) {
  this.id = id;
  this.value = value || 'default value';
  this.parentElement = parent;
  this.createElements(this.id);
  this.attachEvents();
 },
 createElements: function(id) {
  this.containerElement = document.createElement('div');
  this.parentElement.appendChild(this.containerElement);
  this.staticElement = document.createElement('span');
  this.containerElement.appendChild(this.staticElement);
  this.staticElement.innerHTML = this.value;
  this.fieldElement = document.createElement('input');
  this.fieldElement.type = 'text';
  this.fieldElement.value = this.value;
  this.containerElement.appendChild(this.fieldElement);
  this.saveButton = document.createElement('input');
  this.saveButton.type = 'button';
  this.saveButton.value = 'Save';
  this.containerElement.appendChild(this.saveButton);
  this.cancelButton = document.createElement('input');
  this.cancelButton.type = 'button';
  this.cancelButton.value = 'Cancel';
  this.containerElement.appendChild(this.cancelButton);
  this.convertToText();
 },
 attachEvents: function() {
  var that = this;
  addEvent(this.staticElement, 'click', function() { that.convertToEditable(); });
  addEvent(this.saveButton, 'click', function() { that.save(); });
  addEvent(this.cancelButton, 'click', function() { that.cancel(); });
 },
 convertToEditable: function() {
  this.staticElement.style.display = 'none';
  this.fieldElement.style.display = 'inline';
  this.saveButton.style.display = 'inline';
  this.cancelButton.style.display = 'inline';
  this.setValue(this.value);
 },
 save: function() {
  this.value = this.getValue();
  var that = this;
  var callback = {
   success: function() { that.convertToText(); },
   failure: function() { alert('Error saving value.'); }
  };
  ajaxRequest('GET', 'save.php?id=' + this.id + '&value=' + this.value, callback);
 },
 cancel: function() {
  this.convertToText();
 },
 convertToText: function() {
  this.fieldElement.style.display = 'none';
  this.saveButton.style.display = 'none';
  this.cancelButton.style.display = 'none';
  this.staticElement.style.display = 'inline';
  this.setValue(this.value);
 },
 setValue: function(value) {
  this.fieldElement.value = value;
  this.staticElement.innerHTML = value;
 },
 getValue: function() {
  return this.fieldElement.value;
 }
};
var titlePrototypal = clone(EditInPlaceField);
titlePrototypal.configure(' titlePrototypal ', $('doc'), 'Title Here');
var currentTitleText = titlePrototypal.getValue();
/* EditInPlaceArea对象*/
var EditInPlaceArea = clone(EditInPlaceField);
// Override certain methods.
EditInPlaceArea.createElements = function(id) {
 this.containerElement = document.createElement('div');
 this.parentElement.appendChild(this.containerElement);
 this.staticElement = document.createElement('p');
 this.containerElement.appendChild(this.staticElement);
 this.staticElement.innerHTML = this.value;
 this.fieldElement = document.createElement('textarea');
 this.fieldElement.value = this.value;
 this.containerElement.appendChild(this.fieldElement);
 this.saveButton = document.createElement('input');
 this.saveButton.type = 'button';
 this.saveButton.value = 'Save';
 this.containerElement.appendChild(this.saveButton);
 this.cancelButton = document.createElement('input');
 this.cancelButton.type = 'button';
 this.cancelButton.value = 'Cancel';
 this.containerElement.appendChild(this.cancelButton);
 this.convertToText();
};
EditInPlaceArea.convertToEditable = function() {
 this.staticElement.style.display = 'none';
 this.fieldElement.style.display = 'block';
 this.saveButton.style.display = 'inline';
 this.cancelButton.style.display = 'inline';
 this.setValue(this.value);
};
EditInPlaceArea.convertToText = function() {
 this.fieldElement.style.display = 'none';
 this.saveButton.style.display = 'none';
 this.cancelButton.style.display = 'none';
 this.staticElement.style.display = 'block';
 this.setValue(this.value);
};

3.混合类

/* 混合类 */
/* 混合函数 */
function augment(receivingClass, givingClass) {
 for(methodName in givingClass.prototype) {
  if(!receivingClass.prototype[methodName]) {
   receivingClass.prototype[methodName] = givingClass.prototype[methodName];
  }
 }
}
/* 改进的增加函数 */
function augment(receivingClass, givingClass) {
 if(arguments[2]) { // Only give certain methods.
  for(var i = 2, len = arguments.length; i < len; i++) {
   receivingClass.prototype[arguments[i]] = givingClass.prototype[arguments[i]];
  }
 }
 else { // Give all methods.
  for(methodName in givingClass.prototype) {
   if(!receivingClass.prototype[methodName]) {
    receivingClass.prototype[methodName] = givingClass.prototype[methodName];
   }
  }
 }
}
var EditInPlaceMixin = function() {};
EditInPlaceMixin.prototype = {
 createElements: function(id) {
  this.containerElement = document.createElement('div');
  this.parentElement.appendChild(this.containerElement);
  this.staticElement = document.createElement('span');
  this.containerElement.appendChild(this.staticElement);
  this.staticElement.innerHTML = this.value;
  this.fieldElement = document.createElement('input');
  this.fieldElement.type = 'text';
  this.fieldElement.value = this.value;
  this.containerElement.appendChild(this.fieldElement);
  this.saveButton = document.createElement('input');
  this.saveButton.type = 'button';
  this.saveButton.value = 'Save';
  this.containerElement.appendChild(this.saveButton);
  this.cancelButton = document.createElement('input');
  this.cancelButton.type = 'button';
  this.cancelButton.value = 'Cancel';
  this.containerElement.appendChild(this.cancelButton);
  this.convertToText();
 },
 attachEvents: function() {
  var that = this;
  addEvent(this.staticElement, 'click', function() { that.convertToEditable(); });
  addEvent(this.saveButton, 'click', function() { that.save(); });
  addEvent(this.cancelButton, 'click', function() { that.cancel(); });
 },
 convertToEditable: function() {
  this.staticElement.style.display = 'none';
  this.fieldElement.style.display = 'inline';
  this.saveButton.style.display = 'inline';
  this.cancelButton.style.display = 'inline';
  this.setValue(this.value);
 },
 save: function() {
  this.value = this.getValue();
  var that = this;
  var callback = {
   success: function() { that.convertToText(); },
   failure: function() { alert('Error saving value.'); }
  };
  ajaxRequest('GET', 'save.php?id=' + this.id + '&value=' + this.value, callback);
 },
 cancel: function() {
  this.convertToText();
 },
 convertToText: function() {
  this.fieldElement.style.display = 'none';
  this.saveButton.style.display = 'none';
  this.cancelButton.style.display = 'none';
  this.staticElement.style.display = 'inline';
  this.setValue(this.value);
 },
 setValue: function(value) {
  this.fieldElement.value = value;
  this.staticElement.innerHTML = value;
 },
 getValue: function() {
  return this.fieldElement.value;
 }
};
/* EditInPlaceField class. */
function EditInPlaceField(id, parent, value) {
 this.id = id;
 this.value = value || 'default value';
 this.parentElement = parent;
 this.createElements(this.id);
 this.attachEvents();
};
augment(EditInPlaceField, EditInPlaceMixin);
/* EditInPlaceArea class. */
function EditInPlaceArea(id, parent, value) {
 this.id = id;
 this.value = value || 'default value';
 this.parentElement = parent;
 this.createElements(this.id);
 this.attachEvents();
};
// Add certain methods so that augment won't include them.
EditInPlaceArea.prototype.createElements = function(id) {
 this.containerElement = document.createElement('div');
 this.parentElement.appendChild(this.containerElement);
 this.staticElement = document.createElement('p');
 this.containerElement.appendChild(this.staticElement);
 this.staticElement.innerHTML = this.value;
 this.fieldElement = document.createElement('textarea');
 this.fieldElement.value = this.value;
 this.containerElement.appendChild(this.fieldElement);
 this.saveButton = document.createElement('input');
 this.saveButton.type = 'button';
 this.saveButton.value = 'Save';
 this.containerElement.appendChild(this.saveButton);
 this.cancelButton = document.createElement('input');
 this.cancelButton.type = 'button';
 this.cancelButton.value = 'Cancel';
 this.containerElement.appendChild(this.cancelButton);
 this.convertToText();
};
EditInPlaceArea.prototype.convertToEditable = function() {
 this.staticElement.style.display = 'none';
 this.fieldElement.style.display = 'block';
 this.saveButton.style.display = 'inline';
 this.cancelButton.style.display = 'inline';
 this.setValue(this.value);
};
EditInPlaceArea.prototype.convertToText = function() {
 this.fieldElement.style.display = 'none';
 this.saveButton.style.display = 'none';
 this.cancelButton.style.display = 'none';
 this.staticElement.style.display = 'block';
 this.setValue(this.value);
};
augment(EditInPlaceArea, EditInPlaceMixin);

点评：

js分为类和对象、函数。
其中又包含多种形式，属性，数组属性，函数，私有函数，公有函数，静态函数。
小的基础方法，可以有大的用途，比如extend方法，clone方法，还有augment方法。

更多关于JavaScript相关内容可查看本站专题：《JavaScript常用函数技巧汇总》、《javascript面向对象入门教程》、《JavaScript中json操作技巧总结》、《JavaScript切换特效与技巧总结》、《JavaScript查找算法技巧总结》、《JavaScript动画特效与技巧汇总》、《JavaScript错误与调试技巧总结》、《JavaScript数据结构与算法技巧总结》、《JavaScript遍历算法与技巧总结》及《JavaScript数学运算用法总结》

希望本文所述对大家JavaScript程序设计有所帮助。