CODEWITHSUNDEEP
javascriptnode.jsasynchronous
gbam
gbam

Reputation: 1484

NodeJS - Update an Object with returned Promise

I've been struggling with promises. No matter how many phrasing of this question I read I can't sort it out.

I have a lab class / function which has a property of deployed (boolean). I want to check to see if the lab is deployed. I already have a lab object thus I call lab.isDeployed(). However when this returns - it returns true or false however I no longer can access the original lab object because of this asynchronous 'feature'. 

function lab(id) {
    this.deployed = null; //This is the property.
    this.isDeployed = function(){
        return isLabDeployed(this.id, this.userID).then(function(data){ 
            return data; //Where Data is a query to determine if its deployed.
        });
}

This is called from another method. 

l.isDeployed().then(function(data){
    expect(data).to.be.equal(false);;
});

Should I pass the lab object back to the original method? IE instead of returning data above, should I update the deployed property and return this? Or is there another way? I tried to limit the code as I was hoping for an explanation.

Upvotes: 0

Views: 520

Answers (2)

haotang
haotang

Reputation: 5738

You're still be able to access l object

l.isDeployed().then(function(data){
    expect(data).to.be.equal(false);
    console.log(l.deployed) // lab object still accessible here
});

Or with async/await:

const data = await l.isDeployed()
console.log(l.deployed) // lab object still accessible here

Upvotes: 1

Roni Peled
Roni Peled

Reputation: 38

Try doing something like this:

this.isDeployed() = function() {
    return new Promise(
        (resolve, reject) => {
            isLabDeployed(this.id, this.userID)
                .then((data) => {
                    resolve(data);
                });
        }
    );

Then, you can call the isDeployed function as a promise. 

this.isDeployed()
    .then((data) => {
        // this is where you use your data.
    });

Otherwise, you might want to use async/await

const data = await this.isDeployed()

Basically you want to resolve the data you get as a promise. You might even be able to do something simple like.

this.isDeployed() = isLabDeployed(this.id, this.userId)

Upvotes: 1

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