[THRIFT-2376] nodejs: allow Promise style calls for client and server

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.2
• Fix Version/s: 0.9.2
• Component/s: Node.js - Compiler
• Assignee: Henrique Mendonca
• Reporter: Pierre Lamot
• Created: 23/Feb/14 16:38
• Updated: 05/Mar/14 21:14
• Resolved: 23/Feb/14 19:20

Description

the idea of this patch is to allow writing server functions and clients calls using future/promise style.

for instance a server function:

{
  divide: function(n1, n2, result) {
    if (n2 === 0) {
      var x = new ttypes.InvalidOperation();
      result(x);
      return;
    }
    result(null, n1/n2);
  }
}

might be written as:

{
  divide: function(n1, n2) {
    if (n2 === 0) {
      throw new ttypes.InvalidOperation();
    }
    return n1/n2;
  }
}

both style remains valid, the style to use is detected according to the function signature (is there a last argument for the callback).

when using promise style, a promise can also be return in stead of the result for asynchronous results.

the client side might use promise as well:

client.calculate(1, work, function(err, message) {
  if (err) {
    console.log("InvalidOperation " + err);
  } else {
    console.log('Whoa? You know how to divide by zero?');
  }
});

might be written as:

client.calculate(1, work)
  .then(function(message) {
        console.log('Whoa? You know how to divide by zero?');
  })
  .fail(function(err) {
    console.log("InvalidOperation " + err);
  });