How to validate and handle a form in Express (NodeJS)

Is there a preferred form handling and validation library for Express?

I'm really looking for a similar level of abst开发者_如何学JAVAraction as is found in Django forms - i.e. validation and error reporting in the template.

If the same validation could be used on the client side, that would be great.

Has anyone used, or written, anything good?

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It looks like there's a module for this located at https://github.com/caolan/forms. I've never used it, but it seems fairly full featured.

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This also looks viable and is still being developed: https://github.com/ctavan/express-validator

Here's an example of validating a form submission (login post request):

exports.login.post = function(req, res){
  req.assert('username', 'Enter username').notEmpty();
  req.assert('password', 'Enter password').notEmpty();
  res.locals.err = req.validationErrors(true);

  if ( res.locals.err ) {
    if ( req.xhr ) {
      res.send(401, { err: res.locals.err });
    } else {
      res.render('login', { err: res.locals.err });
    }

    return;
  }

 //authenticate user, data is valid
};