Model Validation

[bookshelf]

Model Validation

[calmdev]

I believe this is exactly what I needed. Can you verify if the implementation is ok? I want to share it incase others are interested in this. Your example above demonstrates use for more complex cases, I think - which is pretty cool.

Model:

var User = Bookshelf.Model.extend({
    tableName: 'users',
    initialize: function() {
        this.on('saving', this.validate, this);
    },
    validations: {
        email: ['required', 'validEmail'],
        username: ['required', 'alphaNumeric'],
        age: ['isNumeric']
    },
    validate: function(model, attrs, options) {
        return CheckIt(this.toJSON()).run(this.validations);
    }
});

Usage:

User.forge({
    email: 'invalid@testcom',
    username: 'joe-invalid'
}).save().then(function(user) {
    console.log(user.toJSON());
}, function(errors) {
    console.log(errors.toJSON());
    // { email: 'The email must contain a valid email address', username: 'The username must only contain alpha-numeric characters' }
});

[tgriesser]

Hey @calmdev - So I'm actually writing a separate library for validation... https://github.com/tgriesser/checkit

I'll advertise/give examples for it a bit more once I polish things up - the docs and test suite are still a little bare, but in my own projects it's been working great so-far... I've been using it alongside Bookshelf and it works well (especially with the use of promises)... Feel free to check it out and see how you like it (and open any tickets/pull requests if things aren't working as you'd expect).

My reasoning here is that (in my experience) you'll very often want to validate models differently based on access control, special cases, etc... so I figured it'd be better to separate this out and provide hooks for than to try getting validators all tangled up with the relation logic.

[tgriesser]

I actually may provide a bare bones integration for it once it's done. But here's a very brief example use in a model:

initialize: function() {
   this.on('saving', this.validate, this);
},

validations: {
  user: {
      email: ['required', 'validEmail'],
      password: ['required']
  },
  admin: {
      email: ['required', 'validEmail'],
  }
}

validate: function(model, attrs, options) {
   options.role || (options.role = 'user') {
     return CheckIt(this.toJSON()).run(this.validations[options.role]);
   }
}

Then saving...

model.save({email: '[email protected]'}, {role: req.user.acl});

[calmdev]

Ok, well that makes sense to me - I agree with the reasoning. I wanted to ask that way I don't do anything that goes against the progression of this project as I want to continue using it - very promising. I am going to check out the work that you have started with the checkit library.

Thanks for the example.

I was going to ask about it, but then it suddenly appeared as I was typing this reply. I will try it out!

[tgriesser]

Yeah, that looks good - the only thing that might be an issue there is if you get an error that isn't a CheckIt error but is for some reason another error (database or whatever)... then you likely won't have a toJSON method... so what I've been doing so far is a instanceof check to determine whether to call toJSON on the error object.

Here's an example with express:

var errorHandler = function(res) {
   return function(error) {
      if (error instanceof CheckIt.Error) {
        res.json(400, {error: error.toJSON()});
      } else {
        res.json(400, {error: error.message});
      }
   };
};

// Elsewhere ...
.save().then(function(user) {
    console.log(user.toJSON());
}).catch(errorHandler(res));

[calmdev]

Excellent. Thanks for the tip.

[ErisDS]

Just an idea, but it would be cool to provide an example using node-validator

[pon]

We've tried implementing this pattern using Bookshelf and CheckIt. Everything behaves as expected, except we are seeing a "Possibly unhandled TypeError: Invalid validation" error logged. We are handling the error in the forge promise, but it is still being logged. I'm curious if this is expected behavior or something that other people have run in to.

[tgriesser]

@PeteOtto can you show the code you're running into that with? You shouldn't get any possibly unhandled errors if all goes well.

[pon]

https://gist.github.com/peteotto/9415651

[tgriesser]

I've updated my comment above... It's generally an anti-pattern to do .then(onSuccess, onError) because if an error is thrown in the onSuccess it's not handled.

Your code example would be better written as:

create = {
  handler: function(request, reply) {
    return new Address().save({
      name: request.payload.name,
      address_line1: request.payload.address_line1
    }).then(function(model) {
      return new Address({
        'id': model.id
      }).fetch();
    }).then(function(model) {
      return reply(model);
    }).catch(function(error) {
      return reply(error);
    });
  }
};

[pon]

Thanks Tim - I'll give that a try!

[bendrucker]

@PeteOtto The create handler can be cut down a whole lot:

create = {
  handler: function(request, reply) {
    return new Address().save({
      name: request.payload.name,
      address_line1: request.payload.address_line1
    })
    .call('fetch')
    .then(reply)
    .catch(reply);
  }
};

[thetutlage]

It is mandatory to use checkit , i want to use https://www.npmjs.org/package/indicative , but for some reason it does not work

[bendrucker]

Not at all @thetutlage. Please open a new issue though if you're having trouble.