Server redirect implementation

[ruslansp]

Server redirect implementation

[sneko]

Hi @ruslansp ,

If you look at

vue-cli-plugin-ssr/lib/app.js

Lines 112 to 162 in ea4aeef

	// Render the Vue app using the bundle renderer
	const renderApp = (req, res) => {
	res.setHeader('Content-Type', 'text/html')
	const context = Object.assign({
	req,
	url: req.url,
	title: config.defaultTitle,
	httpCode: 200,
	}, config.extendContext && config.extendContext(req, res, process))
	renderer.renderToString(context, (err, renderedHtml) => {
	let html = renderedHtml
	if (err || context.httpCode === 500) {
	console.error(`error during render url : ${req.url}`)
	// Render Error Page
	let errorHtml = config.error500Html
	? fs.readFileSync(config.error500Html, 'utf-8')
	: '500 | Internal Server Error'
	if (err) {
	console.error(err)
	if (!isProd) {
	const errorMessage = `<pre>${err.stack}</pre>`
	config.error500Html
	? errorHtml = errorHtml.replace('<!--server-error-msg-->', errorMessage)
	: errorHtml += errorMessage
	}
	if (config.onError) {
	config.onError(err)
	}
	}
	html = errorHtml
	res.status(500)
	} else {
	res.status(context.httpCode)
	}
	if (config.onRender) {
	config.onRender(res, context)
	}
	res.send(html)
	})
	}

no matter context properties you set (like a status code of 301/302...) the code will always end with

vue-cli-plugin-ssr/lib/app.js

Line 160 in ea4aeef

res.send(html)

So even if I use context.req.res.redirect(302, '/xxxx'); somewhere, line 160 will try to send something... and it seems that's a problem since 302/301 HTTP response should only have minimal headers, no content...

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at ServerResponse.setHeader (_http_outgoing.js:482:11)
    at ServerResponse.header (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/express/lib/response.js:767:10)
    at ServerResponse.send (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/express/lib/response.js:170:12)
    at renderer.renderToString (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/@akryum/vue-cli-plugin-ssr/lib/app.js:119:15)
    at /Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:9536:15
    at RenderContext.done (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:9187:15)
    at RenderContext.next (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2588:19)
    at RenderContext.cachedWrite [as write] (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2451:9)
    at RenderContext.next (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2602:25)
    at RenderContext.cachedWrite [as write] (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2451:9)
    at RenderContext.next (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2602:25)
    at RenderContext.cachedWrite [as write] (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2451:9)
    at RenderContext.next (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2602:25)
    at RenderContext.cachedWrite [as write] (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2451:9)
    at RenderContext.next (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2602:25)
    at RenderContext.cachedWrite [as write] (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:2451:9)
(node:4202) UnhandledPromiseRejectionWarning: Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at ServerResponse.setHeader (_http_outgoing.js:482:11)
    at ServerResponse.header (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/express/lib/response.js:767:10)
    at ServerResponse.send (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/express/lib/response.js:170:12)
    at renderer.renderToString (/Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/@akryum/vue-cli-plugin-ssr/lib/app.js:119:15)
    at /Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:9536:15
    at /Users/XXXXXXXXXX/Documents/YYYYYYY/node_modules/vue-server-renderer/build.dev.js:9170:20
(node:4202) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)

[sneko]

Hi @ruslansp , did you find how to do that?

Thank you,

[sneko]

@Akryum maybe you have an idea on this? I saw multiple issues about that

Here is an example: https://stackoverflow.com/a/57925996/11314316 could be great to be able overriding all your error catching logic. We could like that custom if we send html or not depending on httpCode (applied only for redirections 301/302?)

Thank you,

[ruslansp]

Hi. In version v0.6.0 added extendContext parameter in config. You can add respose to context and continue to use res for redirect. Not sure, but it seems you can solve it this way.
I’m not using it myself.

[almunnings]

Does #225 help with this?

It's allowed me to do something like:

In app set a variable like this.$root._routeRedirect = '/something'

entry-server.js

context.rendered = () => {
  // ...
  context._routeRedirect = app._routeRedirect || null
}

then in vue.config.js

For 404s I was just setting

extendContext = (req, res, process) => {
  const extension = {}
  if (req.path === '/404') {
    extension.httpCode = 404
  }
  return extension
}

For redirects based on a vue instance condition, changing the response's status late, to not match context.httpCode will stop res.send(html) from sending, stopping errors.

onRender = (res, context) => {
  if (context._routeRedirect) {
    res.redirect(301, context._routeRedirect)
  }
}

[sneko]

2 years since then! And upgrading some Vue librairies makes the error Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client crashing the server now! Whereas before it was just some innocent logs... haha (that I had ignored for the ease)!

To keep my own logic of redirecting within components with this.$ssrContext.req.res.redirect(302, redirectUri) I just did a patch/PR #289 (@sonuku yours sounded a bit more complicated to me but I appreciate nonetheless!).

Hope this helps :)