async.map which works on objects

I had a use case just now for async.map which iterates on the values of an object, and whose callback has a new object with the original keys pointing to the translated values of the same keys.

async.map as it exists doesn’t allow this, and I couldn’t see another method which does the same (please let me know if I missed it).

I think it’d be useful feature.

In the mean time, I faked it with underscore by doing async.map(_.values(obj), ... and then in the callback using _.object(_.keys(obj), transformed).

[JumpLink]

Another Version of @glukki 's Wrapper:

  async.objectMap = function ( obj, func, cb ) {
    var i, arr = [], keys = Object.keys( obj );
    for ( i = 0; i < keys.length; i += 1 ) {
      var wrapper = {};
      wrapper[keys[i]] = obj[keys[i]];
      arr[i] = wrapper;
    }
    this.map( arr, func, function( err, data ) {
      if ( err ) { return cb( err ); }
      var res = {};
      for ( i = 0; i < data.length; i += 1 ) {
          res[keys[i]] = data[i];
      }
      return cb( err, res );
    });
  }

[tremby]

Great – thanks.