Assuming that your geojson contains data similar to the following:
{"type":"Feature","properties":{"name":"Ireland"},"geometry":
{"type":"Polygon","coordinates":[[-6.197885,53.867565],[-6.032985,53.153164],
[-6.788857,52.260118],[-8.561617,51.669301],[-9.977086,51.820455],
[-9.166283,52.864629], [-9.688525,53.881363],[-8.327987,54.664519],
[-7.572168,55.131622],[-7.366031,54.595841],[-7.572168,54.059956],[-6.95373,54.073702],
[-6.197885,53.867565]]]},"id":"IRL"},
You can then extract the properties from this object and create corresponding properties in your model definition.
Subsequently, you can instantiate your model by passing the geojsonobject into the model constructor:
var Ireland = new MyCountryModel(my_geojson_object);
In order to handle JSON parsing from server responses, you should define a method parse(response)
within your model and/or collection definitions. This method accepts a server response object (as a string) as an argument and is expected to return a parsed JSON
object that can be used for initializing collections/models.