Rails AJAX表单验证

Question

Where is the best place to implement form validation for an AJAX form in rails when I'm not using a model for the form? And how would I go about implementing it?

My form being submitted needs to check if an IP address exists and is valid before the methods in the controller are run. If the IP is invalid, I'd like to let the user know via a flash[:danger] message.

views/tools/forms/_ping.html.erb

<%= form_tag ping_tool_path(1), role: "form", class: "form-inline form_ip", name: "ping-form", method: "post", remote: true do %>
    <%= text_field_tag :ip, params[:ip], class: "form-control" %>
    <%= submit_tag "Ping", name: nil, class: "btn btn-default" %>
<% end %>

views/tools/ping.js.erb

$(".output").html("<%= j (@results) %>");

controllers/tools_controller.rb

def ping
    ping_host(params[:ip])
    save_host(params[:ip])

    # AJAX
    respond_to do |format|
      format.js
    end
end

Answer 1

It will depend on how much time and how much scalable your application is or intends to be.

For a more scalable solution, I would use active_interaction gem, create a new interaction and put the validation on it.

here is the docs https://github.com/orgsync/active_interaction

If you want a easier solution you can always create a private method on the controller that validates the ip.

edited

    private

    require 'resolv'

    def valid_ip?(ip)
      case ip
      when Resolv::IPv4::Regex
        return true
      when Resolv::IPv6::Regex
        return true
      else
        return false
      end
    end

inspired on this article http://spin.atomicobject.com/2013/08/28/ruby-ip-address-regex/

edit 2

linking both parts

in your controller

    def ping
        if valid_ip?(params[:ip])
          ping_host(params[:ip])
          save_host(params[:ip])
          render json: { message: "sucess" }
        else
          render json: { errors: "Invalid Ip" }, status: 422
        end
    end

javascript

    <script>
      $(document).ready(function(){
        $('.form_ip').on('ajax:success',function(e, data, status, xhr){
          // success message
          alert("success");
        }).on('ajax:error',function(e, xhr, status, error){
          // errors handler
          var errors = $.parseJson(xhr.response_text).errors;
          alert(errors);
        });
      });
    </script>

source -> http://travisjeffery.com/b/2012/04/rendering-errors-in-json-with-rails/

And If you want to validate before the user submits too, take a look at html5 input pattern attribute http://www.w3schools.com/tags/att_input_pattern.asp