Client data fetching in beforeMount mixin double-fetches

[phil294]

Option 2, Fetch data after the matched view is rendered, calls asyncData in beforeMount.

The pseudo-syntax is

if (asyncData)
  asyncData()

This does not check if asyncData was already called by the server! Thus, guided by the official docs, this leads to duplicate fetches. In the case of dynamic module registration, even to duplicate modules.

What is the suggested way around this? Could we please have some documentation here?

If this issue is unclear, I explain it in greater detail at vuejs/vue#9252, including a repro link. But it is more of a docs issue

[LinusBorg]

This belongs into the Vue repository where the code for the server-render is maintained.

This repository here is only for the docs.

[LinusBorg]

Reopened afer I realized this does belong here after all (related: #210)

[phil294]

This was fixed nicely with #214 with the addition of serverPrefetch() and updated docs. Great.

Store code splitting with preserveState: true does not work for me (state is missing; shouldnt it be preserveState: false server-side anyway? nothing to preserve here, hence empty state), however that is a seperate issue, not to be handled here.