CODEWITHSUNDEEP
angularjspromiseqangular-promise
user2857125
user2857125

Reputation: 226

Chaining promises with parameters?

I was wondering if there is a sugar shorthand for the following in AngularJS:

$scope.parseSomeString = function (str) {
    console.log(str);
    // ...
};

someService.fnA($scope.arg1) // fnA doesn't return anything
    .then(function () {
        return someService.fnB($scope.arg2, $scope.arg3()) // fnB returns some, e.g. string
    })
    .then($scope.parseSomeString); // this shorthand is great!

What I would like to do is something like this:

someService.fnA($scope.arg1)
    .then(someService.fnB($scope.arg2, $scope.arg3())) // but of course, this just calls the function; not good
    .then($scope.parseSomeString); // this shorthand is great!

Any way to bind the arguments $scope.arg2 and $scope.arg3() to fnB?

Upvotes: 0

Views: 945

Answers (1)

PSL
PSL

Reputation: 123739

You could pass in a bound function reference with your arguments using function.bind (look at support and shim for older browsers) to bind the arguments to the function when it is invoked.

someService.fnB.bind(this, $scope.arg2, $scope.arg3);

You could pass null as the first argument as well if you don't need to set a specific context(which you don't, it looks like), if you need you can pass that context as the first argument.

Try:-

someService.fnA($scope.arg1)
.then(someService.fnB.bind(this, $scope.arg2, $scope.arg3)) // but of course, this just calls the function; not good
.then($scope.parseSomeString); // this shorthand is great!

You could also use angular.bind

someService.fnA($scope.arg1)
  .then(angular.bind(this, someService.fnB, $scope.arg2, $scope.arg3))...

Similarly you will find similar methods in the libraries you may already been using like Lodash/underscore has bind, jquery has $.proxy etc..

Upvotes: 3

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