Create an editor widget

Create a simple editor widget

The following example shows the basic structure of a widget class and creates a simple widget for entering a valid email address.

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Note

Use the Optimizely eslint-plugin-cms tool to verify that only public non-deprecated Optimizely Content Management System (CMS) API's are used when creating widgets.

define(
  [
    "dojo/_base/declare",
    "dijit/_Widget",
    "dijit/_TemplatedMixin"
  ], 
  function(
    declare,
    _Widget,
    _TemplatedMixin
  ) {
      return declare([_Widget, _TemplatedMixin], 
        {
          // templateString: [protected] String
          // A string that represents the default widget template.
          templateString: '<div> \
          <input type="email" 
                 data-dojo-attach-point="email" 
                 data-dojo-attach-event="onchange:_onChange" /> \
                 </div>'
        })
    }
);

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Note

The code snippet inherits from the dijit/_TemplatedMixin class, which lets you create a template for the user interface of the widget in either a local string or an external HTML file. You can attach to elements in the template, giving you a programmatic reference to that node in the widget, and you also can attach events to event handlers in our widget.

When the widget is created, the initial value is not available. The initial value is set with set('value', value) and can be called multiple times when loading the editor user interface. To make sure you update the value in the text box when it is set on the widget, declare a _setValueAttr method:

_setValueAttr: function (value) 
  {
    // summary : Sets the value of the widget to "value" and updates the value displayed in the textbox.
    // tags    : private
    
    this._set('value', value);
    this.email.value = this.value || '';
  }

The _setValueAttr method also references a variable named email, which is the textbox DOM node; it is automatically assigned to this variable name by the dijit/_Templated class when it parses the data-dojo-attach-point in the template code.

When you must populate the changes made in the widget, call the onChange method and pass a value to it. You should call onChange as often as necessary during editing to provide an accurate preview of changes.

_onChange: function (event) 
  {
    // summary : Handles the textbox change event and populates this to the onChange method.
    // tags    : private
    
    this._set('value', event.target.value);
    this.onChange(this.value);
  }

The _onChange method is a private event handler triggered when a change is made on the text box. It is configured in the template using the data-dojo-attach-event syntax. After it has updated the value, it calls the onChange method, which in turn causes a page to update.

onChange: function (value) 
  {
    // Event
  }

The following example shows how to update the user interface when a user types. In the postCreate method, connect to the onKeyDown and onKeyUp events on the text box element if the intermediateChanges property is set to true.

postCreate: function () 
  {
    // summary : Connects keyboard events of the email textbox to update the value of the editor.
    // tags    : protected
   
    if (this.intermediateChanges) 
      {
        this.connect(this.email, 'onkeydown', this._onIntermediateChange);
        this.connect(this.email, 'onkeyup', this._onIntermediateChange);
      }
  },
    
_onIntermediateChange: function (event) 
  {
    // summary : Handles the textbox key press events event and populates this to the onChange method.
    // tags    : private
    
    if (this.intermediateChanges) 
      {
        this._set('value', event.target.value);
        this.onChange(this.value);
      }
  }

You can also control where you set the focus when the control loads by implementing the focus method.

focus: function () 
  {
    // summary : Put focus on this widget.
    // tags    : public
    
    dijit.focus(this.email);
  }

A complete example of how to create a custom widget (a StringList) can be found in the Alloy template site available on GitHub.

Check out a topic on how to register a custom editor widget on the server side for how to use the custom editor.

Editor widget properties

There are a few important widget properties worth mentioning:

• intermediateChanges – Indicates whether the onChange method is used for each value change or only on demand.
• label – Title of the property to be edited.
• value– Value of the widget.
• required – Indicates whether this widget requires a value.

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Note

You can add properties for a particular widget by using a property EditorDescriptor.

Editor widget methods

• onChange – Callback event that should be raised from within the widget when the value has changed. The wrapper displaying this widget listens to this event and updates the user interface when it occurs.
• focus – Called when the widget is displayed, should focus on the start element in the widget.
• isValid – Called during validation when an item saves; true if the current value is valid.

Validation

To support validation, the widget must implement the isValid method.

The constraints for a property are mixed into the widget when it is constructed. For example, if the value has the required checkbox selected in the admin view, then that is passed through as the property required.

isValid: function () 
  {
    // summary : Indicates whether the current value is valid.
    // tags    : public
    
    var emailRegex = '[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+';
    if (!this.required) 
      {
        emailRegex = '(' + emailRegex + ')?';
      }
    var regex = new RegExp('^' + emailRegex + '$');
    return regex.test(this.value);
  }

To add a custom error message when validating, the widget must implement the getErrorMessage method.

errorMessage: "",
    isValid: function () {
        // summary : Indicates whether the current value is valid.
        // tags    : public
                        
        if (this.value.length < 10) {
            this.errorMessage = "email should have at least 10 characters";
            return false;
        }                    
        if (this.value.indexOf("optimizely.com") < 0) {
            this.errorMessage = "email should come from optimizely.com";
            return false;
        }
        var emailRegex = "[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+";
        if (!this.required) {
            emailRegex = "(" + emailRegex + ")?";
        }
        var regex = new RegExp("^" + emailRegex + "$");
        return regex.test(this.value);
    },
    getErrorMessage: function () {
       return this.errorMessage;
    }

Manage child dialog boxes

If your widget needs to launch a dialog box of its own, extend an additional class with epi-cms/widget/_HasChildDialogMixin, and set a few property values in the correct place to ensure that the blur event (going from the main dialog box to the new one) does not close the main dialog box.

The class provides one additional property called isShowingChildDialog, used in the blur event of the main dialog to determine whether it should hide itself. If you want to prevent the hiding of the main dialog box when the widget launches a child dialog box, set the value to true before launching the child dialog box, then set it back to false after the child dialog box closes.

_showChildDialog: function () {
    var dialog = dijit.Dialog({
      title: 'Child Dialog'
    });
    this.connect(dialog, 'onHide', this._onHide);
    this.isShowingChildDialog = true;
    dialog.show();
  },

  _onHide: function () {
    this.isShowingChildDialog = false;
  }

Use the custom editor

[ClientEditor(ClientEditingClass = "alloy/component/EmailEditor")]
    public virtual string Email { get; set; }

or creating an EditorDescriptor:

[ClientEditor(ClientEditingClass = "alloy/component/EmailEditor")]
public virtual string Email {
  get;
  set;
}

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Note

Without the UIHint, all string properties will be affected and will use the custom EmailEditor widget.

Related topics

• Example StringList editor widget from Alloy MVC
• Optimizely eslint-plugin-cms tool