Retrieving Results from Sequenced Promises

Question

Retrieving Results from Sequenced Promises

I am facing an issue with returning data from a chained promise. In the following scenario, how can this be achieved?

Here is some pseudocode:

mark = function(){
        return promiseA
    .then(function(data){ .....})
    .then(function(data){return new OBJECT});
}

steve = function() { mark().SomeProperty}

The problem is that mark() is returning undefined. If I return a new Object from the first .then, everything works fine. I need to be able to return data from the third or fourth chained promise. How can I make that happen?

javascript angularjs

Answer 1

Answer №1

In order to fix your function syntax, it is important to incorporate the .then function which will execute once the promise has been resolved.

Sample Code

function update(){
        return promiseA
    .then(function(data){ .....})
    .then(function(data){return new OBJECT});
}

update().then(function(data){
   name = data.SomeProperty;
});

Answer 2

In order to fix your function syntax, it is important to incorporate the .then function which will execute once the promise has been resolved.

Sample Code

function update(){
        return promiseA
    .then(function(data){ .....})
    .then(function(data){return new OBJECT});
}

update().then(function(data){
   name = data.SomeProperty;
});

Answer 3

Answer №2

It appears you are referring to this

getInfo().then( result => data = result.SomeInfo )

Answer 4

It appears you are referring to this

getInfo().then( result => data = result.SomeInfo )

Answer 5

Answer №3

When working with promises, it's important to remember that the promise itself will not return any value directly. Instead, you need to set a variable with the desired value once the promise is resolved. Here's an example:

Here's a simple pseudocode example:

var result = '';

promiseA
    .then(function(data) { return data })
    .then(function(data) { result = new OBJECT });
}

steve = function() { result.SomeProperty }

I shared this solution before seeing @pankaj-parkar's answer, which might actually be a better approach depending on the specific case.

Answer 6

When working with promises, it's important to remember that the promise itself will not return any value directly. Instead, you need to set a variable with the desired value once the promise is resolved. Here's an example:

Here's a simple pseudocode example:

var result = '';

promiseA
    .then(function(data) { return data })
    .then(function(data) { result = new OBJECT });
}

steve = function() { result.SomeProperty }

I shared this solution before seeing @pankaj-parkar's answer, which might actually be a better approach depending on the specific case.

Retrieving Results from Sequenced Promises

Answer №1

Answer №2

Answer №3

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