Ruby on Rails - Railscasts #263 Client Side Validations

Step-by-Step Tutorial: Implementing Client-Side Validations in Ruby on Rails

1. Add Client-Side Validations Gem to Your Gemfile:

   • Open your Gemfile and add the client-side validations gem. You can find the link to the gem in the show notes of the video.
   • Run the bundle command in your terminal to install the gem.

2. Run the Generator Provided by the Gem:

   • In your terminal, run the following command to generate the necessary files for the gem: rails g client_side_validations:install.
   • This command will create configuration files and include them in your Rails project.

3. Configure Field Error Display:

   • Locate the initializer file generated by the gem in the initializers directory.
   • Uncomment the section to override the field_error_proc to display error messages inline next to each form field.

4. Update Your Form with Validation Options:

   • In your form where you have form fields, add the validate: true option to enable inline validation.
   • This option will display the validations in line with the form fields.

5. Handling Complex Validations:

   • Client-side validations can handle complex validations automatically, such as format checks, length validations, and matching confirmations.
   • Update your model with these validations, and they will be translated to JavaScript for inline display.

6. Validates Uniqueness of:

   • Client-side validations also support database-level validations like validates_uniqueness_of.
   • Test this by entering duplicate data in the form fields to see the error message displayed in real-time.

7. Customize Error Message Styling:

   • Customize the CSS to style the error messages to match your application's design.
   • Update the CSS for the field with errors and the error message class to personalize the appearance of error messages.

8. Create Custom Validations:

   • If you need to create custom validations with complex logic, follow these steps:
     • Create a custom validator class in a new file in the lib directory.
     • Update your application.rb config file to load the custom validator.
     • Specify the default error message for the custom validation.
     • Add the custom validator to your model with the necessary attributes.

9. Translate Custom Validations to JavaScript:

   • Create a new JavaScript file for the custom validator to handle client-side validation logic.
   • Add the necessary JavaScript code to perform validations locally.
   • Include the custom JavaScript file in your application layout file.

10. Test Custom Validations:

    • Try entering invalid data in the form fields to see the custom validation error messages displayed inline.
    • Validate that the custom JavaScript logic works by tabbing away from the field to trigger the error message display.

11. Further Customizations:

    • Once you have implemented client-side validations, you can easily add more custom validations for a smoother user experience.
    • Explore adding more validations using client-side validations for instant feedback to users.

By following these steps, you can implement client-side validations in your Ruby on Rails application to provide real-time feedback to users and enhance the overall user experience.