How to decouple a customized loopback-component-passport user model in Loopback?

[Steeve Fong]

Hello everyone,

I'm trying to build a decoupled user-model component that can be injected into a project without the need for further configurations.

My approach was to define a middleware 'loopback-user' in 'auth' phase with codes as follow :

var loopback = require('loopback');

var passport = require('loopback-component-passport');

var providers = require('./providers.json');

function loadModel(jsonFile, baseModel) {

  var modelDefinition = require(jsonFile);

  return baseModel.extend(modelDefinition.name,

    modelDefinition.properties,

    {

      relations: modelDefinition.relations

    });

}

exports.userIdentity = loadModel('./lib/models/user-identity.json', passport.UserIdentity);

exports.userCredential = loadModel('./lib/models/user-credential.json', passport.UserCredential);

var UserModel = loadModel(loopback.User, './lib/models/user.json');

// setup user custom application logic

exports.user = require('./lib/models/user')(UserModel);

module.exports = function loopbackUser (options) {

  var opts = options || {};

  exports.user.autoAttach = opts.datasource || 'db';

  exports.userIdentity.autoAttach = opts.datasource || 'db';

  exports.userCredential.autoAttach = opts.datasource || 'db';

  var PassportConfigurator = passport.PassportConfigurator;

  return function loopbackUser (req, res, next) {

    var passportConfigurator = new PassportConfigurator(req.app);

    passportConfigurator.init();

    passportConfigurator.setupModels({

      userModel: exports.user,

      userIdentityModel: exports.userIdentity,

      userCredentialModel: exports.userCredential

    });

    for (var provider in providers) {

      var config = providers[provider];

      config.session = config.session !== false;

      passportConfigurator.configureProvider(provider, config);

    }

    next();

  };

};

I tried to setup the module loopback-component-passport using some settings from loopback-example-passport. But, I got the following error trace:

500 AssertionError: user must be a descendant of loopback.Model

•    at EventEmitter.app.model (/Users/.../node_modules/loopback/lib/application.js:132:5)
•    at loopbackUser (/Users/.../server/middleware/loopback-user/index.js:32:13)
•    at Layer.handle [as handle_request] (/Users/.../node_modules/loopback/node_modules/express/lib/router/layer.js:82:5)
•    at trim_prefix (/Users/.../node_modules/loopback/node_modules/express/lib/router/index.js:302:13)
•    at /Users/.../node_modules/loopback/node_modules/express/lib/router/index.js:270:7
•    at Function.proto.process_params (/Users/.../node_modules/loopback/node_modules/express/lib/router/index.js:321:12)
•    at next (/Users/.../node_modules/loopback/node_modules/express/lib/router/index.js:261:10)
•    at compression (/Users/.../node_modules/compression/index.js:207:5)
•    at Layer.handle [as handle_request] (/Users/.../node_modules/loopback/node_modules/express/lib/router/layer.js:82:5)
•    at trim_prefix (/Users/.../node_modules/loopback/node_modules/express/lib/router/index.js:302:13)

 I played around within the different loopback phases and I got different errors :

'initial' phase : The model type must be a constructor error.

'final' phase : the user model is not exposed over rest.

Is this implementation currently possible? Is something's missing?

Any approach suggestions?

Thank you in advance.

[jmls]

Hi Steeve (?) 

Did you get anywhere with this ?

Thanks