Delay execution in Angular until a callback is finished running before proceeding

Question

Delay execution in Angular until a callback is finished running before proceeding

I'm struggling to grasp how callbacks function within my code. My current task involves creating a function that validates user input and includes an HTTP GET call to the API for additional checking.

The issue lies in the fact that the validate function is being called from the process function, and the submit function executes before the HTTP call in validate(). Unfortunately, I can't modify the process function as it's utilized by other components.

form.process = function(){
     // do stuffs
     validate();
     submit();
}

form.validate = function () {
    // lots of checks regarding the model
    ...
    // HTTP GET call
}

Is there a way to make the submit function wait until the HTTP GET call in validate() is complete?

Appreciate any insights :)

javascript angularjs asynchronous callback asynccallback

Answer 1

Answer №1

It is crucial to update the validate function to return a promise in this manner:

form.validate = function () {
    var deferred = $q.defer();
    // multiple checks on the model
    ...
    // In http GET call:
    // If successful
    deferred.resolve(<any value>);
    // If errors occur
    deferred.reject(<any value>);
    // now return the promise
    return deferred.promise;
}

Subsequently, you are able to execute various tasks within the process function as follows:

form.process = function(){
   // perform actions
   validate().then(function(response){
      submit();
   }, function(reject){
      // handle errors such as displaying an error message.
   });
}

If there are other components utilizing this function, they must be updated accordingly in the same way. This approach is considered optimal for integrating additional GET calls into each "validate" function of your components.

Answer 2

It is crucial to update the validate function to return a promise in this manner:

form.validate = function () {
    var deferred = $q.defer();
    // multiple checks on the model
    ...
    // In http GET call:
    // If successful
    deferred.resolve(<any value>);
    // If errors occur
    deferred.reject(<any value>);
    // now return the promise
    return deferred.promise;
}

Subsequently, you are able to execute various tasks within the process function as follows:

form.process = function(){
   // perform actions
   validate().then(function(response){
      submit();
   }, function(reject){
      // handle errors such as displaying an error message.
   });
}

If there are other components utilizing this function, they must be updated accordingly in the same way. This approach is considered optimal for integrating additional GET calls into each "validate" function of your components.

Delay execution in Angular until a callback is finished running before proceeding

Answer №1

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