递归承诺链末尾的链动作

Question

I'm currently attempting to chain another .then() to the end of a recursive promise chain with the Bluebird library.

My code looks something like this

exports.fetchAll = function() {

  fetchItems = function(items) {
    return somethingAsync()
      .then(function(response) {
        items.push(response.data);
        if (response.paging.next) {
          fetchItems();
        } else {
          return items;
        }
      })
      .catch(function(error) {
        console.log(error);
      });
  }

  return fetchItems([], 0);
}

/// In Some other place

fetchAll().then(function(result){ console.log(result); });

As of now, .then at the end of the fetchAll call is returned immediately. How do I make it such that it executes at the end of my recursive chain?

Answer 1

When you are recursively invoking the function, fetchItems , you need to return the value, like this

if (response.paging.next) {
  return fetchItems();        // Note the `return` statement
} else {
  return items;
}

Now, the fetchItems returns another promise and the then at the end will be invoked only after that promise is resolved.