"Error while loading route: undefined " when setting route model hook about emberfire

[stefanpenner]

I am unsure if it is directly related, but I noticed.

https://github.com/firebase/emberFire/blob/master/src/data.js#L181 doesn't enqueue an actual error object, which likely is resulting in a poor error message.

This is due to crappy error logging in the router: https://github.com/emberjs/ember.js/blob/master/packages_es6/ember-routing/lib/system/router.js#L525
opened an issue: emberjs/ember.js#4691

But in general it is best practice to reject with error objects

[aputinski]

@jrhe I went to https://emberfire-test.firebaseio.com/posts.json in the browser and it looks like your Firebase doesn't have any data at the /posts location

@stefanpenner I'll update that so it throws an actual error.

[bnjamin]

@aputinski Does that mean you have to bootstrap your firebase with some data? If not, how are you then supposed to handle empty collections?

[mbykovskyy]

Luckily I haven't hit this problem yet because I'm accessing a non-existing child collection through a record that does exist in firebase and it works well. But I see a future use case where I will hit this problem. I went through the code to understand why it was working in my case and interestingly I noticed that if you access a non-existing collection (could be anything really) through a parent record like so this.modelFor('post').get('comments') emberFire gets the post and then emberData converts comments attribute to an Ember.Array which in turn converts an undefined to an empty array.

Usually it's a good practice to return empty objects as opposed to null or undefined, however, how would you detect that resource doesn't exist in that case? If one chooses to display an error message for example.

You can handle the rejection like so,

var route = this;

return new Ember.RSVP.Promise(function(resolve, error) {
  resolve(route.store.find('post'));
}).then(function(value) {
  return value;
}, function(reason) {
  return [];
});

[stefanpenner]

simplification of @mbykovskyy example

route.store.find('post').catch(function(reason) {
  // check if reason tells us it was just "not found"
  return [];
});

[mbykovskyy]

Nice one @stefanpenner!

[aputinski]

@stefanpenner would there be any harm in returning an empty array in the adapter if no data was found instead of rejecting?

https://github.com/firebase/emberFire/blob/master/src/data.js#L257

[stefanpenner]

@aputinski I am unsure

[jrhe]

I knew that I had no data but I couldn't figure out how to create it
correctly through the GUI and I assumed that that it would have created the
collection if I tried to create a record.

On 11 April 2014 17:54, Stefan Penner [email protected] wrote:

@aputinski https://github.com/aputinski I am unsure

Reply to this email directly or view it on GitHubhttps://github.com//issues/39#issuecomment-40225338
.

[jrhe]

@aputinski Your fixes work well.

[idesignedme]

will using {{link-to 'HOME' 'home'}} break an app? also is this discouraged?
should I be using {{#link-to}}HOME{{/link-to}} instead. I'm wondering if this is the reason my app seems to break