How can we add custom remote validator without the ClientSideValidations::Middleware::Base like in the wiki

[dinatih]

wiki : https://github.com/DavyJonesLocker/client_side_validations/wiki/Custom-Validators#remote-validators

System configuration

Client Side Validations version: after this commit 35501c1b120a3d0d5b8a907e4edd6d7b826378e6

Is there another way to add custom remote validators, please ?

[factor4]

I solved that as follows:

# config/routes.rb
resources :users do
  collection do
    get :check_my_value
  end
end

# controllers/users_controller.rb
def check_my_value
  user = User.new(my_value: params[:id])
  user.validate
  if user.errors[:my_value].blank?
    head :ok
  else
    render json: { error: "My error message." }, status: :not_found
  end
end

// app/assets/javascripts/users.js
ClientSideValidations.validators.remote['my_value'] = function(element, options) {
  if ($.ajax({
    url: '/users/check_my_value',
    data: { id: element.val() },
    // async *must* still be false. Could not find another solution in a hurry...
    async: false
  }).status == 404) { return "My error message."; }
  // TODO Fetch the error message from the Ajax response.
}

It's up to you to protect the method from unauthorized access. In my case only logged in users can access it, but this will not fit any use-case e.g. register a new user.

[dinatih]

Thanks you @factor4 I will try that.

[tagliala]

@factor4 thanks.

Still hadn't time to fix the wiki

Please also be aware of information disclosure and DOS attacks: the above endpoints should be protected with something like rack-attack

[tagliala]

Hmm... just remembered about this comment: https://github.com/DavyJonesLocker/client_side_validations/issues/710#issuecomment-312624313

I just need to copy & paste to the wiki and add disclaimers

[tagliala]

Wiki updated: https://github.com/DavyJonesLocker/client_side_validations/wiki/Custom-Validators#remote-validators