Question

I’m looking for an end to end example using dojo.store with dijit.Tree over REST.

There are many existing examples that use the older dojo api, dojo.data.api, but a dearth of ones using the dojo.store api.

Is the reason that dijit.Tree doesn’t fully support dojo.store yet?
If so, do I need to use the dojo.data.ObjectStore wrapper to encapsulate dojo.store for use with dijit.tree?

I saw one example of working around this by extending StoreFileCache:
http://dojo-toolkit.33424.n3.nabble.com/New-object-store-and-dijit-Tree-td2680201.html

Is that the recommended option, or should I

a) stick to dojo.data.api until dijit.Tree supports dojo.store directly, or

b) use the dojo.data.ObjectStore wrapper

Thanks

Answer 1

There is now a tutorial on the DTK website that seems to cover pretty much exactly this topic.

http://staging.dojotoolkit.org/documentation/tutorials/1.6/store_driven_tree/

However, as I know linking to something without giving an answer is considered a poor practice, the general idea is that rather than using a dojo.data.ObjectStore to wrap around it and then potentially shoving it through a ForestStoreModel, you can simply augment your dojo.store-based store to add the methods that the Tree will look for. Here’s a simple example from the tutorial:

usGov = new dojo.store.JsonRest({
    target:"data/",
    mayHaveChildren: function(object){
        // see if it has a children property
        return "children" in object;
    },
    getChildren: function(object, onComplete, onError){
        // retrieve the full copy of the object
        this.get(object.id).then(function(fullObject){
            // copy to the original object so it has the children array as well.
            object.children = fullObject.children;
            // now that full object, we should have an array of children
            onComplete(fullObject.children);
        }, onError);
    },
    getRoot: function(onItem, onError){
        // get the root object, we will do a get() and callback the result
        this.get("root").then(onItem, onError);
    },
    getLabel: function(object){
        // just get the name
        return object.name;
    }
});

It’s worth noting that in this case, we’re making some assumptions about what the data looks like. You’d need to know how your children relate and customize the methods below for that purpose, but it’s hopefully fairly clear as to how to do that for yourself.

You can also just stick to dojo.data APIs for now, but this approach definitely feels more lightweight. It takes a couple of layers out of the stack and working with customizing a dojo.store-based store is much easier.