ExtJS 4.1 - Retrieve hasOne information for Nested JSON

1
votes

I am attempting to retrieve the information for a Model and an associated model that contains a hasOne association. I was referencing the following Sencha documentation page (http://docs.sencha.com/ext-js/4-1/#!/guide/data). I currently have the following sample code working:

var Mtd = Ext.ModelMgr.getModel('Mtd');
 Mtd.load(4, {
     success: function(mtd){
         console.log("Loaded! " + mtd.get('id'));
         mtd.getTreatmentdesign(function(treatment,operation){
             console.log(treatment.get('id'));
         }, this);
     }
 });

Now, when I call mtd.getTreatmentdesign(), I notice that two requests are made to retrieve information. The first one is to retrieve the Mtd information which I am expecting but then it's also making a request to retrieve the Treatmentdesign information. The response for the Mtd contains the Mtd information as well as the Treatmentdesign information. So I want to process the Mtd and Treatmentdesign information with one request. It puzzled me that the documentation stated the following:

You may be wondering why we passed a success function to the User.load call but didn't have to do so when accessing the User's posts and comments. This is because the above example assumes that when we make a request to get a user the server returns the user data in addition to all of its nested Posts and Comments. By setting up associations as we did above, the framework can automatically parse out nested data in a single request.

So how can I retrieve associated information without having to make another request? I simply just want to use all the json from a single request as opposed to having to make multiple requests.

2
javascriptextjs4.1

2 Answers

1
votes

Be sure to set the associationKey config on the HasOne association to the property that contains the data for the associated model. By default, this is the name of the associated model class in all lowercase letters.

For instance, if the data for an Mtd record is returned by the server in the form

{
    ...
    treatmentDesign: {
       ...
    }
}

set the associationKey to 'treatmentDesign'.

Here's an example in action: http://jsfiddle.net/HP6fq/3/

0
votes

Yes, associationKey works

Ext.define('User', {
    extend:'Ext.data.Model',
    fields: ['id', 'name', 'status'],
    associations: [{ type: 'hasOne', model: 'Status', associationKey: 'status'  }]
});

Ext.define('Status', {
    extend:'Ext.data.Model',
    fields: ['id', 'title'],
});

Demo here