[1.x] Return early when using router.on() during SSR

[RobertBoes]

When using router.on() it is always executed, this means the following won't work during SSR:

<script setup>
import { router } from '@inertiajs/vue3'

router.on('start', (event) => {
  console.log(`Starting a visit to ${event.detail.visit.url}`)
})
</script>

Instead, we'd need to wrap this in a onMounted hook, or check if the document/window exists;

<script setup>
import { router } from '@inertiajs/vue3'
import { onMounted } from 'vue'

onMounted(() => {
  router.on('start', (event) => {
    console.log(`Starting a visit to ${event.detail.visit.url}`)
  })
})
</script>

But since router.on() is already just a wrapper for document.addEventListener() I'd expect the wrapper to take care of that for you.

A simple fix I've made here is to simply check if we're in ssr with the isServer constant, if it is we return an empty void function

[pedroborges]

I tested the proposed fix locally, and it works as expected. It aligns with other methods that return early in SSR mode.

Previously, using router.on() during SSR caused the following error:

[Vue warn]: Unhandled error during execution of setup function 
  at <Layout errors= {} appName="Vue 3 Playground" >
ReferenceError: document is not defined
    at F.on (file:///Users/pedro/Code/open-source/inertia/playgrounds/vue3/bootstrap/ssr/ssr.mjs:301:5)
    at setup (file:///Users/pedro/Code/open-source/inertia/playgrounds/vue3/bootstrap/ssr/ssr.mjs:648:8)
    at _sfc_main$6.setup (file:///Users/pedro/Code/open-source/inertia/playgrounds/vue3/bootstrap/ssr/ssr.mjs:741:25)
    at callWithErrorHandling (/Users/pedro/Code/open-source/inertia/node_modules/@vue/runtime-core/dist/runtime-core.cjs.js:192:19)
    at setupStatefulComponent (/Users/pedro/Code/open-source/inertia/node_modules/@vue/runtime-core/dist/runtime-core.cjs.js:7551:25)
    at setupComponent (/Users/pedro/Code/open-source/inertia/node_modules/@vue/runtime-core/dist/runtime-core.cjs.js:7512:36)
    at renderComponentVNode (/Users/pedro/Code/open-source/inertia/playgrounds/vue3/node_modules/@vue/server-renderer/dist/server-renderer.cjs.js:620:15)
    at renderVNode (/Users/pedro/Code/open-source/inertia/playgrounds/vue3/node_modules/@vue/server-renderer/dist/server-renderer.cjs.js:752:14)
    at renderComponentSubTree (/Users/pedro/Code/open-source/inertia/playgrounds/vue3/node_modules/@vue/server-renderer/dist/server-renderer.cjs.js:707:7)
    at renderComponentVNode (/Users/pedro/Code/open-source/inertia/playgrounds/vue3/node_modules/@vue/server-renderer/dist/server-renderer.cjs.js:638:12)

[joetannenbaum]

Looks good, thanks!

[pedroborges]

Thanks, @RobertBoes!