Ext JS Models (
Ext.data.Model class) defaults to having an ID property named
id. This field will be automatically created for you and be mapped to the
id field in your incoming data. By knowing where the unique key for the model lies we can make use of some handy methods on the model, such as
findById on an
In this snippet we can see that 3 fields are created - our two explicit fields, and the automatically created id field.
However, our data will often use an ID field that isn't
userId) and so we have to tell the model which field to use instead. We do this simply by setting the
idProperty config when defining our model.
With this config in place we see that only 2 fields are created.
Loading Model Data
Ext.data.Model class definition we can use its static
load method to load in data for a specific ID. If we take our first example, which uses the default
id field, and call the
User.load method with an ID of 1 we can see the AJAX call passes a parameter named
id with a value of 1. No surprises there, our server would use this to lookup the data and send it back.
Now let's take our second example, which has the
idProperty set to
userId, and call the
User.load method again.
I would have expected the parameter that is sent to the server to use the
idProperty name (
userId) but instead the default of
id is still sent - not ideal when our server expects
To get around this we need to add a config to the proxy -
idParam. This works in a similar way to
idProperty and tells the proxy which field and name to use when dealing with IDs.
Now if we look at the AJAX call made it passes a