dojowidgetcloneduplication

Duplicate dijit widget instead of recreating it

Is there a way by which I can duplicate or clone dijit widgets?

Basically, idea is to improve page rendering performance by minimizing widget creation time.

We have a single page web application and we do not reload the entire page whenever the user performs any action.

The flow of events is as follows,

  1. The main page is loaded by the browser. It contains a dijit ContentPane which acts as a master container and displays the entire page using various other dijit widgets like textboxes, tabs, datefield, Enhanced grid etc.

  2. The user performs an action (e.g. click on a dijit button)

  3. The application sends an ajax call to server which processes the button click event and generates UI of the next page.

  4. Browser receives successful response from ajax call and calls refresh method of dijit ContentPane. Which triggers destruction of existing widgets and new set of widgets are created and placed at appropriate position. (instead of refreshing the entire page)

  5. The user again performs some action and again the refresh method is called which triggers destruction of existing widgets and new set of widgets are created and placed at appropriate position.

Because of such architecture the browser has to destroy existing widgets and recreate them again and again. Which results in slow performance.

The idea is to have a set of widgets always readily available on the browser clone them and place at appropriate position and update them instead of recreating each time.

Solution

  • Yes this is possible with something called _AttachMixin.

    Basically there is no getting around the fact that your widgets would need to attach event listeners to the HTML Document. What can be cut out though is the time in the Dijit Widget's lifecycle to generate the DOM. As we well know, simple Dijit widgets like a dijit/form/Button has a div inside a div inside a div etc.

    This is explained in detail here http://dojotoolkit.org/reference-guide/1.9/dijit/_AttachMixin.html

    Here is an example using Node.JS as a backend. http://jamesthom.as/blog/2013/01/15/server-side-dijit

    This is a tough problem and this concept isn't explained very thoroughly. If you have a backend that is not Node.JS you have to manually make the widget string and pass it as a response to your AJAX and an follow the example from the 1st link (Ref Doc)

    We have had lots of widgets of our app render nicely within the client side. A far less complicated approach would be to simply show / hide (instead of render and destroy) widgets as and when they are needed. I assume that you app's access policy would focus on data and not which person has access to which widget.