CODEWITHSUNDEEP
javascriptreactjsasynchronousreact-nativepromise
J Dorrian
J Dorrian

Reputation: 204

Returning a value from a Promise: [Object Object]

React Native Development:

I am in the process of building a react native application and I'm learning the basics needed to understand promises. I am finding it difficult to work out why some things are happening. My biggest issue so far is that the value I return from a promise is not accessible to me. Here is my function and here is the console log:

Function:

getUri(){
    var data = this.apiclient.retrieveImages()
    var outside_uri = data.then((uri) => { console.log('inside => ' + uri); return uri;})
    console.log('outside => ' + outside_uri)
 }

Console log:

outside => [object Object]
inside => https://firebasestorage.googleapis.com/v0/b/facelapse-50017.appspot.com/o/Q…M0p7x1ROK0yIN02%2F001?alt=media&token=31de9def-cd32-4d5c-ad65-f3f65ad76685

A quick observation: The outside is printing before the inside (possibly because of the async nature of a promise).

Upvotes: 1

Views: 2784

Answers (1)

J Dorrian
J Dorrian

Reputation: 204

Solution: By making my entire function asyncronous and making the outside_uri await the execution of the promise, the outside was no longer being evaluated before the promise was completed.

async getUri(){
    var data = this.apiclient.retrieveImages()
    var outside_uri = await data.then((uri) => { console.log('inside => ' + uri); return uri;})
    console.log('outside => ' + outside_uri)
 }

Upvotes: 3

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