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How do I return an object in my case?

I have a function that can return a normal or http request object.

I have something like

var t = function() {
    var obj
    var test;
    //code to determine test value

//return object depends on test value, 
//if test is undefined, return regular obj, 
//if not make a http request.
    if (!test){
          return obj;
    }
    return getObj(url) 
        .then(function(obj){
            return obj
        })
}

var getObj = function() {
    return $http.get(url);    
}

var open = function() {
   //this won't work for regular object, it has to be http object
    return t()
        .then(function(obj) {
            return obj;
        })
}

var obj = open();

How can I check if an object is returned via an HTTP request or a regular object?

Thanks for the help!

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4 answers


If I understand correctly your problem with the object being returned t

is a promise or not to chain. You can always wrap the object $q.when(obj)

to ensure that the returned object is always a promise and can be bound. You must be sure to enter the $q

way you are doing $http

. Or just circle the test value with var obj = $q.when(value)

and return obj

.

var t = function() {
    var obj; 
    var test;
    //code to determine test value
    if (!test){
       return $q.when(obj); //<-- return $q.when
    }
    return getObj(url) 
        .then(function(obj){
            return obj
        })
}

var getObj = function() {
    return $http.get(url);    
}

var open = function() {
    //this will always work now on
    //return t(); should be enough as well
    return t()
        .then(function(obj) {
            return obj;
        })
}


when (value): Wraps an object, which can be a value or (third party), and then can promise in a promise in $ q. This is useful when you are dealing with an object that may or may not be a promise, or if the promise comes from a source that cannot be trusted.

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You can check if the type t is a function or an object. For it to be called, it must be entered as a function.



//this won't work for regular object, it has to be http object
if( typeof t !== "function" ){
 //return; or handle case where t is a plain object
}
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Modified code

Skip callback method

var t = function(cb) {
    var obj
    var test;
    //code to determine test value

//return object depends on test value, 
//if test is undefined, return regular obj, 
//if not make a http request.
    if (!test){
          cb(obj);
    }
    return getObj(url) 
        .then(function(obj){
           cb(obj)
        })
}

var getObj = function() {
    return $http.get(url);    
}

var open = function() {
   //this won't work for regular object, it has to be http object
    return t(function(obj) {
            // write code dependent on obj
        })
}

var obj = open();
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You can check if the return object has a promise object or not:

var open = function() {
    var result = t();
    //Verify whether the return object has a promise object or not
    if(angular.isObject(result.promise)
    return result
        .then(function(obj) {
            return obj;
        })
}
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