belongsTo association in Beta2 not working

[j.k]

I've got a couple of nested models with hasMany associations and one store to load my xml file into that model hierarchy. That is working just fine.
All models (except for the root one) have a belongsTo association, so I can obtain the parent node of every sub-node:

		belongsTo: {
			model: "MyApp.model.mymodule.ParentModelXYZ",
			getterName: "getParentNode"
		},

When I call getParentNode() on the model instance I get the following error message:

Error: [ERROR][Anonymous] You are trying to load a model that doesn't have a Proxy specified

That is correct, I don't have proxies specified in the models, my proxy is specified in my store. This used to work in PR2 but not in Beta2 anymore. Is this a bug or is there a workaround?

The raw data in the model instance is correct and does contain the correct parentNode. I did not manually specify foreign keys or something.

I tried to add a belongsTo association in the kitchen sink Nested Loading demo, too, but didn't get that to work either.

Thanks again for your helpful responses,
j.k

[mitchellsimoens]

Are you using TreeStore and NestedList?

[j.k]

No I'm using a regular Store and a customized NestedList implementation, because for some reason I didn't get the NestedList to work as expected (maybe I'll try later again). but I doubt this matters, as the error seems to lie in the Ext.data.Model or BelongsTo implementation.

[mitchellsimoens]

I spent a little bit of time to create a simple example of belongsTo:

Ext.define('Post', {
    extend : 'Ext.data.Model',

    config : {
        fields : ['id', 'user_id'],
        proxy  : {
            type   : 'ajax',
            url    : 'data/json.json',
            reader : 'json'
        }
    }
});

Ext.define('Comment', {
    extend : 'Ext.data.Model',

    config : {
        fields    : ['id', 'user_id', 'post_id'],
        belongsTo : 'Post'
    }
});

Ext.setup({
    onReady: function() {

        var comment = new Comment({
            id      : 1,
            user_id : 1,
            post_id : 1
        });
        
        comment.getPost({
            callback : function(post) {
                console.log(post);
            }
        });

    }
});

This is what I have in my data/json.json

{
    "id" : 1,
    "user_id" : 1
}

This should then console.log out a valid Post model instance after it loaded

[j.k]

Thanks, but this example isn't reflecting the problem I'm having in my app, because:
I don't have a proxy set up in my model, I have a separate store, which loads all the data in my model hierarchy.
If I were to add a proxy config to my root model, the system would reload the entire document, when I call getParentNode() (as in your example), which is unnecessary, because I already did load everything into my various models.

As I said my code worked in PR2, so something must've changed in the way a belongsTo association is resolved.

Let me know if you need more information on that.

[mitchellsimoens]

You will need to put a proxy on the model.

[j.k]

You will need to put a proxy on the model.

No, that definitely can't be true, and it would be terrible if it would - think about it:
for every item I have in my model, if I call getParentNode - and if you put that structure in a nestedlist you call that plenty of times - , the whole XML document is loaded from the web and parsed again, just to resolve the association to the parent node, that just doesn't make sense. And it worked in PR2 and before.

After further investigation and debugging of the Beta 2 code, I found, that it is indeed a bug - or let's say an unwanted side effect of changes made to the code - that the parent nodes are not populated during the initial loading of the document.

The relevant code resides in Ext.data.association.HasMany#read(), which contains the logic to populate a node's parentNode property if you have a hasMany - belongsTo relationship between 2 models:

        //now that we've added the related records to the hasMany association, set the inverse belongsTo
        //association on each of them if it exists
        inverse = this.getAssociatedModel().associations.findBy(function(assoc) {
            return assoc.getType() === 'belongsTo' && assoc.getAssociatedName() === record.$className;
        });
       //if the inverse association was found, set it now on each record we've just created

That code fails, hence inverse remains null, because in Beta 2 the associatedName attribute of every association is not the full class name of the model:

    applyAssociatedName: function(associatedName) {
        if (!associatedName) {
            associatedName = this.getAssociatedModel().modelName;
        }
        associatedName = associatedName.slice(associatedName.lastIndexOf('.')+1);
        return associatedName;
    },

overriding that method with the associatedName = associatedName.slice(...) line commented out fixes this issue and the belongsTo relationship is resolved once again automatically when loading the structure in a store.

If other people happen to run into this problem, here's the code you need to override that behavior to the old one:

Ext.define("MyApp.overrides.Association", {
	override: "Ext.data.association.Association",

	applyAssociatedName: function (associatedName) {
		if (!associatedName) {
			associatedName = this.getAssociatedModel().modelName;
		}
	//	associatedName = associatedName.slice(associatedName.lastIndexOf('.') + 1);
		return associatedName;
	}
});

I hope this change makes it into the final version of ST2.

Also let me just say that I love the ability to just override any method I want in the whole framework with Ext.define() and override, this makes the whole framework so much more flexible, it's fantastic.

kind regards

[j.k]

So, this was just fixed in Beta3, probably should've spent today working on another part of the app - case closed, thanks!

[jgadbois]

Was this reverted in the RC? I'm getting the proxy error now.