Node.js, the pyramid of doom (even with async), can you write it better?

Question

I consider myself a very experienced node.js developer.

Yet I still wonder if there is a better way to write the following code so I don\'t get the pyramid of doom..

Answer 1

I break each level of the pyramid of doom into a function and chain them one to the other. I think it is a lot easier to follow. In the example above i'd do it as follows.

ms.async.eachSeries(arrWords, function (key, asyncCallback) {

  var pgCB;
  var pgClient;

  var connect = function () {
    pg.connect(pgconn.dbserver('galaxy'), function (err, _pgClient, _pgCB) {
      pgClient = _pgClient;
      pgCB = _pgCB;
      findKey();
    });
  };

  var findKey = function () {
    statement = "SELECT * FROM localization_strings WHERE local_id = 10 AND string_key = '" + key[0] + "'";
    pgClient.query(statement, function (err, result) {
      if (pgconn.handleError(err, pgCB, pgClient))
        return;
      // if key doesn't exist go ahead and insert it
      if (result.rows.length == 0) {
        getId();
        return;
      }
      pgCB(); 
      asyncCallback(); 
    });

  };

  var getId = function () {
    statement = "SELECT nextval('last_resource_bundle_string_id')";
    pgClient.query(statement, function (err, result) {
      if (pgconn.handleError(err, pgCB, pgClient))
        return;
      insertKey();
    });
  };

  var insertKey = function () {
    var insertIdOffset = parseInt(result.rows[0].nextval);
    statement = "INSERT INTO localization_strings (resource_bundle_string_id, string_key, string_revision, string_text,modified_date,local_id, bundle_id) VALUES ";
    statement += "  (" + insertIdOffset + ",'" + key[0] + "'," + 0 + ",'" + englishDictionary[key[0]] + "'," + 0 + ",10,20)";
    ms.log(statement);
    pgClient.query(statement, function (err, result) {
      if (pgconn.handleError(err, pgCB, pgClient))
        return;
      pgCB();
      asyncCallback();
    });
  };

  connect();

});