route-transition.md

Route Transition

Slick Router defines route transition as the process of changing from a route state, generally represented by an URL, to another one. It provides tools to control with great granularity the transition like cancel, redirect, stop or retry.

transition object

The transition object is itself a promise. It also contains the following attributes

• id: the transition id
• routes: the matched routes
• path: the matched path
• pathname: the matched path without query params
• params: a hash with path params
• query: a hash with the query
• prev: the previous matched info
  • routes
  • path
  • pathname
  • params
  • query

And the following methods

• then
• catch
• cancel
• retry
• followRedirects
• redirectTo

route

During every transition, you can inspect transition.routes and transition.prev.routes to see where the router is transitioning to. These are arrays that contain a list of route descriptors. Each route descriptor has the following attributes

• name - e.g. 'message'
• path - the path segment, e.g. 'message/:id'
• params - a list of params specifically for this route, e.g {id: 1}
• options - the options object that was passed to the route function in the map

Errors

Transitions can fail, in which case the transition promise is rejected with the error object. This could happen, for example, if some middleware throws or returns a rejected promise.

There are also two special errors that can be thrown when a redirect happens or when transition is cancelled completely.

In case of redirect (someone initiating a router.transitionTo() while another transition was active) and error object will have a type attribute set to 'TransitionRedirected' and nextPath attribute set to the path of the new transition.

In case of cancelling (someone calling transition.cancel()) the error object will have a type attribute set to 'TransitionCancelled'.

If you have some error handling middleware - you most likely want to check for these two special errors, because they're normal to the functioning of the router, it's common to perform redirects.