Migrating koa v1 to v2

Question

I'm using some module with koa and they only have this documentation which is written in koa v1 not v2. and since I've never used v1 before, I have no idea how to write this in v2.

app
  .use(body({
    IncomingForm: form
  }))
  .use(function * () {
    console.log(this.body.user) // => test
    console.log(this.request.files) // or `this.body.files`
    console.log(this.body.files.foo.name) // => README.md
    console.log(this.body.files.foo.path) // => full filepath to where is uploaded
  })

@Jonasw I'm using koa v2, and my whole koa routers are written in v2 as well. the router never works with other routers that are written in v2. and I just want to write all in v2 — Phillip YS, Jul 15 '17 at 09:26
I think replacing function*() with async function (d) , and this with d should do it. — Jonas Wilms, Jul 15 '17 at 09:38
yeah I get that part since I'm used to v2 but how should I deal with this? `console.log(this.body.files.foo.path)` — Phillip YS, Jul 15 '17 at 09:40

Saad · Accepted Answer · 2017-07-15T10:28:51.723

2

Changing from Koa v1 to Koa v2 is a pretty simple process. The only reason for the version bump is that it uses async functions instead of generators for your middleware.

Example v1 Middleware:

app.use(function* (next) {
  yield next
  this.body = 'hello'
})

Example v2 Middleware:

app.use(async (ctx, next) => {
  await next()
  ctx.body = 'hello'
})

use async functions instead of generators, and accept ctx as a parameter instead of using this.

edited Jul 15 '17 at 10:28

answered Jul 15 '17 at 10:12

Saad

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since I'm really used to koa, I get that part. but I have no idea how to deal with `console.log(this.body.files.foo.path) ` – Phillip YS Jul 15 '17 at 10:25
I'm not sure I understand what you mean. It would just be `ctx.body.files.foo.path` instead of `this.body.files.foo.path`. – Saad Jul 15 '17 at 10:27
Also, I had an issue in the example v2, I was accidentally still using a genreator instead of an `async` function. fixed now – Saad Jul 15 '17 at 10:29

score 0 · Answer 2 · answered Jul 15 '17 at 10:08

0

change the function *() to async function(ctx) where ctx in koa2 is like this in koa1

see: http://koajs.com/#context

answered Jul 15 '17 at 10:08

Greg Bacchus

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what should I do with this ? `console.log(this.body.files.foo.path) ` – Phillip YS Jul 15 '17 at 10:25
Assuming that you have a body parser to parse the body, you would do something like `console.log(ctx.request.body.files.foo.path)` – Greg Bacchus Jul 15 '17 at 10:39
I'm using https://github.com/tunnckoCore/koa-better-body. and couldn't figure it out – Phillip YS Jul 15 '17 at 10:44
I have only ever used `koa-bodyparser` so maybe give that a try – Greg Bacchus Jul 15 '17 at 10:45
since `koa-bodyparser` doesn't support multipart-form I obviously needed to use `koa-better-body` but It's quite complicated because all the examples are written in v1 – Phillip YS Jul 15 '17 at 10:47

score 0 · Answer 3 · answered Aug 03 '17 at 17:56

app
  .use(body({
    IncomingForm: form
  }))
  .use(function(ctx) {
    console.log(ctx.body.user) // => test
    console.log(ctx.request.files) // or `this.body.files`
    console.log(ctx.body.files.foo.name) // => README.md
    console.log(ctx.body.files.foo.path) // => full filepath to where is uploaded
  })

Migrating koa v1 to v2

3 Answers3