Help with Dojo Drag & Drop

Question

Hi I am trying to implement some drag and drop functionality into a project but am having a bit of difficulty with a few aspects. One of the problems I am having is with the creation of a custom avatar, I am able to achieve a custom avatar but have to cheat slightly and hide some elements with CSS.

Below is a snippet of my code not the entire code, I have required all necessary pacakges etc.

dojo.query(".canDrag").forEach(function(node, index, nodelist){
        var createSource = new dojo.dnd.Source(
            node, {copyOnly: true, creator: createAvatar}
        );

    function createAvatar(item, hint) {
       var node       = dojo.doc.createElement("span");
       dojo.addClass(node, "avatarStyle");

        if ( hint == "avatar" ) {
            var dHtml = item; 
            console.log("trying " + dHtml);
            node.innerHTML = item;
        } 
        else {

            console.log("if this show remove redudant call");
        }

       return {node: node, data: item, type: "product", copyOnly: true};
    };

Ok so as you can see I create my DnD source then give it a custom creator where I attempt to build my own custom Avatar. The actyual draggable markup is below:

<div class="canDrag panelLeft">
                        <div class="dojoDndItem" dndType="product" title="digitalCamera" id="12345">
                            <h3 class="productTitle"><a href="">Samsung ES71</a></h3>
                            <p class="productType">Compact Digital Camera</p>
                            <img src="img/small_Cam.png" class="imgLMargin" alt="Samsung ES71"/>
                            <div class="dragHandle">
                            </div>
                        </div>
                    </div>

Rather than append the entire div from canDrag and down I would like to grab different elements such as the image and .product title and just display those. If any one has any ideas I thank you in advance also if my question has not been clear enough I can try to rephrase.

Cheers

Answer 1

CSS should be fine. Otherwise, you can either use the dndData attribute for your items, or add the items manually to your DnD source object.

When using dojoDndItem class, Dojo expects the visualization of the avatar to be already resolved in the markup itself. That's why it passes the inner HTML as the item data. This is for the most simple and common case, when you would not use a custom creator. I think using CSS to customize the avatar is fine. Even if you don't use a custom creator to set the avatarStyle class, you can take advantage of the fact that Dojo puts the avatar inside its own container marked with the class dojoDndAvatar (or dojoDndAvatarItem). Take a look at the source at dojo/dnd/Avatar.js.

If you still want to use a custom creator, you have a couple of options:

• Add a dndData attribute to your items. In that case, that's what gets passed to the creator function as the item parameter. It can be anything, and you can use that to further customize the avatar. Eg. you could serialize a JSON object and dynamically create the avatar from that object, or you could set it to a unique id and then use dojo.query() to access the nodes below it.

• Remove the items entirely add them programmatically with the insertNodes() method. In that case, your creator function must implement both the case for the avatar and the case for the actual item.

It doesn't address your question in particular, but here's an excellent Dojo DnD tutorial.

The Dojo reference guide is also helpful, once you understand what's happening. And of course, use the source Luke!