State specific rules and redirects

[josh-hobson]

I have run into a problem in my app using ui-router where I need state specific rules to determine whether or not a user is allowed to view a certain page in the app.

This is the question I asked on stack overflow: http://stackoverflow.com/questions/20472136/state-specific-rules-and-redirects

Having looked through the source however it looks like this can't be done. I could use urlRouterProvider to create rules however the app has a large state tree and requires data loaded in resolves of previous states to calculate the rules of its children. As far as I'm aware, urlRouter is hit first when a new location is provided so in some cases the required data may not have been loaded yet (for example, navigating directly to the url).

A quick example of the use case would be a questionnaire where you don't want the customer to go to page n+1 without having completed page n. A rule on the page state would allow you to quickly check which page they should be viewing.

I believe this could also be useful in other cases, such as having a rule to provide a default child state for an abstract state if no child was provided.

I am willing to put in the time to try and work out how to do this, I'm new to angular UI but would enjoy the work. However I just thought it would be worth checking that:
a) I haven't missed a feature that would achieve this,
b) Someone isn't already working on this,
c) There aren't any reasons against doing state specific rules, philosophical or otherwise.

[nateabele]

This can already be accomplished by attaching custom data to states using the data key (these could even be functions), and then intercepting state transitions with $stateChangeStart and using the state's custom data to evaluate rules. If you have a specific proposal, add some example code to demonstrate how it would work, or close this issue and continue the discussion here: #618 (comment)

[josh-hobson]

Thanks @nateabele. I assumed someone had probably already asked this but just couldn't find an issue regarding it.

For now I will use the state change event, however I will also contribute to the discussion and provide some code for how I would implement it.

[timkindberg]

@josh-hobson if you are feeling crazy, please feel free to add an item on this topic to the FAQ.

[nateabele]

@josh-hobson Yeah, this is still pretty open territory, and I'd be happy to help collaborate on a 3rd-party module if some common patterns emerge.