4.11 - edit-in-place example, mixin.js

JS设计模式源代码

/* Mixin class for the edit-in-place methods. */

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);