who to wrap callbacks with a promise?

Question

Lets say I have a given function I can not change which has a callback function:

markAsRead(item_id,function(result){console.log(result)})

How can I wrap that function with a promise so I could know which item_id was returned? Something like this:

markRead(item_id).then(function(result)
    {
      emailOwner(result)
    },
    function(result)
    {
      emailSystem(result)
});

Where are you getting this promise from, and how would it be resolved ? — adeneo, Apr 17 '14 at 21:17

score 3 · Answer 1 · answered Apr 17 '14 at 21:36

3

function markRead(item_id) {
    return new Promise(function(resolve, reject) {

      markAsRead(item_id,function(result){
          if (/* result is OK */) {
            resolve(result);
          }
          else {
            reject(result);
          }
      })
    });
}

answered Apr 17 '14 at 21:36

lorefnon

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Nice and simple, just what I needed! – esanz91 Nov 05 '15 at 19:34

who to wrap callbacks with a promise?

1 Answers1