Callback Promise "this" is undefined

Help Requests
1

Hi all,

i would like how to resolve this problem:

After a http request with promise, the callback value “this” is undefined…
How can i resolve this?!

Here the callback:

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Here the internal request:

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Thanks for help,
Andrea

2

From your code, something weird happen, and this should be the same with that. But it doesn’t seem to be the case. I think it’s maybe debugger behavior, showing you wrong information?

3

It can be an error of debugger, but the if condition “this.ticketType != this.ticketModel.type” ( Under the tooltip" is alwyas undefined !?!
and “this” is undefined too as “that”

4

Then probably that in that function is referring to lexical scope. Can you show full code of that function that invokes updateTicket ?

5

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1 Like
6

Maybe put a debugger, and go to browser dev tool and check what the after transpiled code looks like, I suspect something got wrong during that phase. The source looks pretty normal to me :thinking:

7

i read this:

but i m not able to understand how to resolve my problem.

1 Like
8

The way onUpdateTicket is declared and how you are passing arrow function to .then guard against what you saw in that question I believe. I think unless you can provide a reproduction or get help from someone who has experienced this before, it’s gonna be a tough one.

9

I had the same problem. I’ve changed this:

Promise.resolve()
.then(this.method)

by this:

Promise.resolve()
.then(() => this.method())

and problem was solved.

1 Like