[angularjs] `ui-router` $stateParams vs. $state.params

Another reason to use $state.params is for non-URL based state, which (to my mind) is woefully underdocumented and very powerful.

I just discovered this while googling about how to pass state without having to expose it in the URL and answered a question elsewhere on SO.

Basically, it allows this sort of syntax:

<a ui-sref="toState(thingy)" class="list-group-item" ng-repeat="thingy in thingies">{{ thingy.referer }}</a>