How can I update/refresh Google MDL elements that I add to my page dynamically?

Question

I'm working with Google Material Design components which are stripped down for simplicity, then rendered more fully when the page is loaded. Simplified below to illustrate the issue:

What shows in the index.html file:

<div class="switch"></div>

What renders to the DOM when the page is loaded:

<div class="switch">
   <div class="switch_track"></div>
   <div class="switch_thumb"></div>
</div>

I am creating a drag and drop HTML editor and have template files for each component type. The template file for a switch is simply:

switch.html

<div class="switch"></div>

The problem is when I drag this to the canvas. jQuery looks at switch.html and renders <div class="switch"></div> to the DOM, but since it was dynamically added, it is not being "seen" by the scripts that added the additional track and thumb tags.

How can I fix this issue so that whenever the DOM is updated, it reruns any scripts? Ideally I would like to avoid touching any of the Material Design script files.

Answer 1

I found the solution in this MDL Github forum post from MDL contributor Jonathan Garbee:

The component handler [ componentHandler.upgradeDom() ] will handle upgrading everything if you just call it with no parameters.

So the pseudo-code of my solution would be:

 // Callback function of jquery-ui droppable element
 drop: function(event, ui) {
    // Add the element from it's template file
    $.get("templates/" + elem + ".html", function(data) {
      $("#canvas").append(data);

      // Expand all new MDL elements
      componentHandler.upgradeDom();
    });
 });

For future readers and users of the Material Design Lite (MDL) framework, you can also refresh dynamically added elements individually (instead of combing the entire DOM).

For example, componentHandler.upgradeDom("mdl-menu") will upgrade only mdl-menu elements.

Further reading here.

Answer 2

You can use the componentHandler.upgradeDom(); for dynamically upgrade the element or use the following lines for downgrade the existing element and upgrade it again

Type 1:

   $(".data").find(".is-upgraded").each(function(){                 
       $(this).removeAttr("data-upgraded").find(".mdl-switch__ripple-container,.mdl-switch__track").remove();  //downgrade the existing upgraded elements
   });
    componentHandler.upgradeDom(); // upgrade the elements

Type 2:

 $(".data").html("{{content}}").promise().done(function(){                 
           componentHandler.upgradeDom(); // upgrade the newest elements 
 });