CODEWITHSUNDEEP
angularjs
crowhill
crowhill

Reputation: 2548

Handling a function where the return might (or might not) be async

I have the following function. It doesn't work, but the idea is that if a sessionStorage variable is already set, use it. If not, make a call to the API and then set the sessionVariable for next time. 

isAdmin: function() {

    // hit the first page, or refreshed.
    if(sessionStorage.getItem("isAdministrator") === null) {
        AzureGroupService.get({adGroup: "Programmers"}).$promise.then(function (data) {
            sessionStorage["isAdministrator"] === data.isMember;
            return data.isMember;
        });
    }
    else {
        return JSON.parse(sessionStorage["isAdministrator"]);
    }
}

So the function might return immediately, or it might need to wait on the API. Is this even close to the right way to do this?

If so, how would I call it in a controller? Something like this?

user.isAdmin().then(function(response) {
    vm.test = response.data;
});

Upvotes: 1

Views: 39

Answers (1)

Sasank Sunkavalli
Sasank Sunkavalli

Reputation: 3964

You can use $q.when() , if the sessionStorage object is not null. Your isAdmin() function should look like this. 

isAdmin: function() {

// hit the first page, or refreshed.
if(sessionStorage.getItem("isAdministrator") === null) {
    return AzureGroupService.get({adGroup: "Programmers"}).$promise.then(function (data) {
        sessionStorage["isAdministrator"] === data.isMember;
        return data.isMember;
    });
}
else {
    return $q.when(JSON.parse(sessionStorage["isAdministrator"]));
}
}

Your controller should look like this , isAdmin() function will always return a promise . So u can define a success callback using .then().

user.isAdmin().then(function(response) {
    vm.test = response.data;
});

Upvotes: 1

Related Questions