Simple: Tell the application controller how to handle exceptions, here a RecordNotFound error.
Do this with the following line:

# application_controller.rb

  rescue_from ActiveRecord::RecordNotFound, :with => :render_404

This will call the method render_404 whenever a RecordNotFound error occurs (you could pass a lambda instead of a symbol, too).
Now write this method:

def render_404
  render 'errors/404', :status => '404'
end

Finally create a 404 document views/errors/errors.html.haml.

%h1 Record Not Found

.error The record you requested could not be retrieved in my database.

Any 404 error that is caused by something not found in your Rails app will render a nice message using your default layout. Similarly, you may catch and handle any other error.

Dominik Schöler

makandra.de

Say thanks2

Last edit

Almost 4 years ago

Dominik Schöler

License

Source code in this card is licensed under the MIT License.

Async control flow in JavaScript: Promises, Microtasks, async/await

Slides for Henning's talk on Sep 21st 2017.

Understanding sync vs. async control flow

Talking to synchronous (or "blocking") API

print('script start')
html = get('/foo')
print(html)
print('s...

Delivering Carrierwave attachments to authorized users only

Preparation

To attach files to your records, you will need a new database column representing the filename of the file. To do this, add a new migration (rails g migration <name>) with the following content:

class AddAttachmentToNotes...

Posted by Dominik Schöler to makandra dev (2011-09-02 14:59)

Rendering a custom 404 page in Rails 2

Related cards:

Introduction

Summary

Understanding sync vs. async control flow

Talking to synchronous (or "blocking") API

Intro

Preparation