Support hash parameter in v-link and improve custom handling

[noirbizarre]

It would be nice to be able to use hash with named route pattern.

Currently

In vue-router 0.7.11, in History/html5 mode:

• hash is automatically extracted from path given as string and scroll to this hash after route change
  (ie. v-link="/page#section" will to to the route /page and scroll to the element with this id (https://github.com/vuejs/vue-router/blob/master/src/index.js#L543-L560)
• there is no way to specify an anchor/a hash with the named route pattern (ie. v-link="{name: 'page', params: {}}")

Proposal

• Add/handle an optional hash or anchor in v-link named route pattern handling (ie. v-link="{name: 'page', hash: 'section'}")
• Add a, optional hash() transition hook called after data hook, if hash value change (same behavior as data hook for hash) :

Vue.component('hash-hook-example', {
  // ... other options
  route: {
    hash (value) {
      console.log(`hash-hook triggered with ${value}`)
    }
  }
})

If the hook is present, it is called. If not, the default behavior (aka. scroll to getElementById(hash)) is executed

[divmgl]

+1 on this, would really like to see links that are create by Vue and can scroll to an anchor

[fnlctrl]

@noirbizarre @divmgl Scrolling to hash is implemented in 2.0, as in scrollBehavior (release notes),

As for hash hook, since all transition hooks are deprecated in 2.0, there won't be any new hooks added, so you can just use a watcher on $route.