Add use method with co-style generator and return a Promise. about mongorito HOT 8 CLOSED

I don't really understand the problem here or how this callback would help. The whole point is to eliminate callbacks at a maximum level. Can you provide some specific example?

from mongorito.

Lets say I want to provide a myapp-data module... and expos a method ".getUser" that returns a promise. And I have a mongodb connection object already...

//elsewhere
Mongrito.models.User = ...;
...

//in my data library - returns a promise that will resolve a user.
exports.authoriseUser = function(username, password) {
  var invalidUsername = new Error("Invalid Username");
  invalidUsername.code = 403;

  var invalidPassword = new Error("Invalid Password");
  invalidPassword.code = 403;

  if (!username) return Promise.reject(invalidUsername);
  if (!password) return Promise.reject(invalidPassword);

  return config.getNamedMongoConnection('user-db')
    .then(function(connection){
      //connection should match an instance of mongodb, or a mongo-spec url string.
      return Mongrito.use(connection, function *(db){
        var User = db.models.User; //context-bound clone of Mongrito.models.User
        var user = yield Users.findOne({ username: username.trim().toLowerCase() });
        if (user == null) throw invalidUsername;
        var valid = yield matchPassword(user, password); //promise
        if (!valid) throw invalidPassword;
        return user;
      });
    });
}

In the above case if Mongrito.use follows co convention, it can resolve a promise against the final user, or the promise chain will reject with the thrown error.

This is much cleaner than having to wrap the alternatives... With a clearly defined scope.

from mongorito.

Still, Mongorito is intended to be used in ES6-only environments, like with Koa framework, which is based on generators at its core. From your example, I assume that you want to execute some code after connection to mongo is established. With Mongorito it does not matter, all operations are buffered and will be executed once connection is there. So after Mongorito.connect, just write the code that operates on db. Imagine, that Mongorito.connect is a synchronous method. Regarding re-using existing mongodb connection, I will consider this for future releases. Immediate note here, it will be possible to re-use existing monk instance, but not a connection from other libraries.

from mongorito.

What I mean is, I have two issues...

First: You aren't using mongodb-style URLs for your connection.

Second: You cannot use Mongorito with multiple databases..

For example, say I have my User information on mongo://foo:2700/users and say, some other collections on mongo://bar:2701/baz ... There's no way to specify which one to use, is there?

The part related to the specific request, is that it would be nice, if you could wrap the code in a promise, so that results can be yielded/resolved out..

What I would like... - no boilerplate code

MyDataLibrary.foo = function(input) {
  return Mongorito.use(connection, function *(db){
    // *** implicit open *** - with context-bound db object

    //use db / db.models.Foo

    return finalResult; // *** implicit close ***
  });
}

What I would need to do with the current library - 13 lines of extr boilerplate

MyDataLibrary.foo = function(input) {
  try {
    Mongorito.open(...);
  } catch(err) {
    return Promise.reject(err);
  }

  //co can wrap this part
  return co(function *(){
    //do stuff - can't have connection to db1 and db2 for different models
    return finalResult;
  })
  .then(function(result){
    Mongorito.close(); //close here
    return result; //re-extend result
  })
  .catch(function(err){
    Mongorito.close(); //close here too
    throw err; //rethrow error
  });
}

elsewhere

MyDataLibrary.foo(someinput).then(function(finalResult){
  //use final result
});

co@4 will return a promise, I was thinking it would be nicer if your library could be used that way as well... where the open/close is implicit, IE: I don't have to call them.

from mongorito.

First: You aren't using mongodb-style URLs for your connection.

Second: You cannot use Mongorito with multiple databases.

Now I understand your issues and yes, those are valid points. I will fix those in the future releases. As for the second problem, I came up with a solution different then you mentioned, but it will achieve the same thing. Thank you for suggestions.

from mongorito.

@vdemedes Thanks... I'm sorry if my request came off with frustration... I do appreciate the work that you have done, was just wanting to offer some observations that could help adopters use your library.

from mongorito.

Absolutely no problem, I just did not catch the idea at first. Moreover, I appreciate that you took the time to create an issue and tell me about your thoughts and suggestions.

from mongorito.

@tracker1 Update, which enables support for mongo:// urls and multiple database connections is pushed to GitHub and NPM under version 0.4.6. Thank you!

from mongorito.