Angular2 typescript promise

Question

I'd like to have a generic http get service I did it using the following code:

public get(module: String): Promise<any> { 
return this.http.get(module)
           .toPromise()
           .then(response => response.json().data as Any[])
           .catch(this.handleError);}

The problem is that now I'd like to know when the http.get is finished to fire a command and I don't know how to do it.

If I add something to the .then step it doesn't work

.then(response => response.json().data as Any[] && alert("HI"))

If I add a .then after the other then, it fires before the http request is fulfilled.

How can I achieve it?

Using dfsq code I'm able to fire alert("HI") but response is undefined. This is the way I use it:

this.dataService.get("myurl").then(response => console.log(response));

I get undefined

"If I add a .then after the other then, it fires before the http request is fulfilled." can you show this code? that is not how promise chaining works — Suraj Rao
– Suraj Rao, Commented Apr 18, 2017 at 14:36

dfsq · Accepted Answer · 2017-04-18 14:36:08Z

1

You indeed need to add one more then block:

public get(module: String): Promise<any> { 
  return this.http.get(module)
           .toPromise()
           .then(response => response.json().data as Any[])
           .then(data => {
             alert("HI") // <---- do something here
             return data
           })
           .catch(this.handleError);
}

Make sure you return previous data from then block so you pass it further down promise chain.

answered Apr 18, 2017 at 14:36

dfsq

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3 Comments

tunoandsuno Over a year ago

Sorry dfsq, the alert("HI") is working but now the response is not working. Why is that? I get undefined from console.log

tunoandsuno Over a year ago

response inside the get function returns the response. But outside the function returns undefined.

dfsq Over a year ago

Where do you put console.log exactly?

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