How to pass params to a callback

Question

I'm trying to find the best practice of implementing the following:
I have 3 functions: manager, httpGet and onsuccess:

manager calls the httpGet function and passes the onsuccess function to be called upon success.
httpGet makes a request and invokes onsuccesss
onsuccess uses needs params from manager

What is the best way to pass and argument from manager to onsuccess without involving httGet?
I was thinking about passing a params object to httpGet which in turn will be passed to onsuccess but I really don't like the idea of passing params to a function that doesn't use them at all.

I found an answer here stackoverflow.com/questions/13199231/… , basically, you can pass the arguments just as the scope of the manager is passed to the onsuccess function. — Krystian Laskowski
– Krystian Laskowski, Commented Jul 20, 2015 at 8:20

Liam · Accepted Answer · 2015-07-20 08:20:23Z

1

You mean something like this:

function manager()
{
   var managerParam =0;
   //the anonymous function below is in the scope of manager() so has
   //access to all of managers parameters
   httpGet(function() {
      //this function can use managerParam
      managerParam ++;
   });

  console.log(managerParam === 1); //true
}

function httpGet(onsuccess)
{
   onsuccess();
}

Fiddle

answered Jul 20, 2015 at 8:20

Liam

30k28 gold badges143 silver badges206 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

xyz · Accepted Answer · 2015-07-20 08:26:36Z

1

Use a closure:

data = { cool: true };
var yourCallbackFunction = function(httpData, notHttpData){};

var bakedCallback = (function() {
    var _data = data;
    return function(httpResp) {
        yourCallbackFunction(httpResp, _data);
    }
})();
httpGet.onSuccess(bakedCallback);

data is the extra data you want to pass to the function.

In your callback: httpData is the data received from request. NOThttpData is the extra data.

edited Jul 20, 2015 at 8:26

answered Jul 20, 2015 at 8:21

xyz

3,4191 gold badge26 silver badges29 bronze badges

Comments

Pavel Gatnar · Accepted Answer · 2015-07-20 08:53:54Z

1

Define onsuccess as local function in manager, it may use its arguments and local variables.
Pass onsuccess to httpGet.

edited Jul 20, 2015 at 8:53

answered Jul 20, 2015 at 8:22

Pavel Gatnar

4,0532 gold badges22 silver badges29 bronze badges

Collectives™ on Stack Overflow

How to pass params to a callback

3 Answers 3

Fiddle

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related