handle errors from the rest adapter

Question

I'm using ember-data, and want to trap and display any errors returned by the rest adapter. I looked at the question here

I added the following code to my model definition:

 becameInvalid: function(errors) {
        alert ("here" + errors);
    },

and the rest adapter returns a 422 (Unprocessable Entity) code

however, the alert doesn't show. Am I missing something, or just being a real newbie numpty?

update #1:

making some progress. The rest server returns the following Json:

{"errors":{ "lastName": ["LastName cannot be blank"] }} 

the model has

becameInvalid: function(errors) { console.log(JSON.stringify(errors)); }, 

however, the console now has the following:

{"email":"jmls@foo,com","firstName":"Julian","id":"aa7c4b42-df64-8fb8-d213-0ad81‌​c9bc213","lastName":"","notes":"ccc"}

which seems to be the json of the record itself, not of the errors.

How can I get to the errors? I have tried

console.log(errors.get("errors.lastName")

but get undefined.

Answer 1

try:

becameError: function(object) {

}

Answer 2

I think that your are missing something, using becameInvalid worked for me.

For example:

App.Person = DS.Model.extend({
    name: DS.attr('string') ,
    becameInvalid: function(errors) {        
        alert(errors.get('errors.name').join(','));
    }
});

Update

Following the suggestion of @fanta, in the commend. Maybe your problem is in the returned json, the expected is:

{
  errors: {
    field_a: ['error a', 'error b'],
    field_b: ['error c']
  }
}

Where field_a must be some field mapped on DS.attr(field_a).

Give a look in that sample http://jsfiddle.net/marciojunior/8maNq/

Answer 3

Try using the DS.rejectionHandler:

DS.rejectionHandler = function(reason) {
  Ember.Logger.assert([reason, reason.message, reason.stack]);

  throw reason;
};

This should catch all errors from the adapter.