If promise does not return value

Question

I have a promise that returns a function, the function does have its own error handling but sometimes for some reason this gets missed (need to explore this later).

I want to add a fallback that if the promise fails/null then return another function.

if (completedForm.isValid()) {
   return formDataQueue.push(formJson, this.company).then(function () {
      return self.trySync();
   });
}

Return self.trySync(): needs a error handler to assume it's not there as if it was commented out. My attempt does not seem to work.

if (completedForm.isValid()) {
   return formDataQueue.push(formJson, this.company).then(function () {
      //return self.trySync();
   }, function(error) {
      router.navigate('home');
   });
}

If `trySync` doesn't return a promise, you can test for that, but if it returns a promise that never resolves, it's going to be harder — adeneo, Oct 14 '16 at 11:20
What exactly do you mean by "*assume it's not there as if it was commented out*". What would cause it to "not be there"? — Bergi, Oct 14 '16 at 11:24

score 1 · Accepted Answer · edited May 23 '17 at 12:16

1

Have a look at the difference between .then(…).catch(…) and .then(…, …).

To handle errors from trySync() (and only from there), you want to use

if (completedForm.isValid()) {
    return formDataQueue.push(formJson, this.company).then(function () {
        return self.trySync().catch(function(error) {
            router.navigate('home');
        });
    });
}

edited May 23 '17 at 12:16

Community

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answered Oct 14 '16 at 11:22

Bergi

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If promise does not return value

1 Answers1