CODEWITHSUNDEEP
ember.js
FellowMD
FellowMD

Reputation: 2260

Debugging Ember.js errors: Error while loading route

While in any particular case there are hints and clues on how to debug an error you get, I haven't really found a general Ember strategy.
For example, a typeError while loading a route:
Assertion failed: Error while loading route: TypeError: 'undefined' is not an object (evaluating 'window.router.lander') (ignore the fact that I'm trying to access window.router.lander. It's irrelevant)

Why does Ember not tell you which route it's loading when this error happens? Or whether it happens in afterModel(), or activate()? And what's the general strategy for finding that sort of context info?

So far all I've got is adding a bunch of console.logs scattered around. For example with the error above:
1) Find all occurrences of window.router.lander in my code
2) before the first occurrence, add a console.log('is it the first occurrence?'), and after the first occurrence put a console.log('its not the first occurrence')
3) Do the same for every occurrence 4) refresh. One of the 'is it the nth occurrence?' won't have a closer, and now you know where the error happened.

Upvotes: 0

Views: 1687

Answers (2)

inDream
inDream

Reputation: 1277

For better debugging, you can enable transitions logging by create app with LOG_TRANSITIONS and/or LOG_TRANSITIONS_INTERNAL properties:

window.App = Ember.Application.create({
  // Basic logging, e.g. "Transitioned into 'post'"
  LOG_TRANSITIONS: true, 

  // Extremely detailed logging, highlighting every internal
  // step made while transitioning into a route, including
  // `beforeModel`, `model`, and `afterModel` hooks, and
  // information about redirects and aborted transitions
  LOG_TRANSITIONS_INTERNAL: true
});

Referenece: http://emberjs.com/guides/understanding-ember/debugging/

Also, you can use canary build which provide detailed error stack: http://emberjs.com/builds/#/canary

Upvotes: 2

edpaez
edpaez

Reputation: 1583

Ember isn't particularly helpful when it comes to errors in the model hook, or the promises it returns. I'm sure I've read in one of the issues (or http://discuss.emberjs.com/ I'm not sure) that this is an open issue in which they're working.

What I do is use the Chrome Developer Tools to debug the issue (instead of just console loggin it). From my experience it's usually:

  1. you're not returning anything in the model hook
  2. an error inside one of the then functions on the promise the model hook returns

I hope it helps you!

Upvotes: 1

Related Questions