After a long hiatus from Rails, I found myself working in a Rails codebase this week. Here at Atomic, our recent focus has been on the wins provided by our starter kit. I still love Ruby and Rails, but after digging through a well-intentioned codebase, I was reminded how much I dislike Rails magic callbacks. Read more on There Be Dragons: Rails Callbacks and Suppression…
Ruby on Rails
Custom Rspec Matcher for N+1 Queries in Rails
Rails and Active Record make many things easy: connecting to the database, building complex queries based on your object model, and easily migrating your schema up, down, and sideways. They also let you very easily introduce N+1 queries. Read more on Custom Rspec Matcher for N+1 Queries in Rails…
How to Set Up a Rails SAML Identity Provider
Security Assertion Markup Language (SAML) is a protocol for single sign-on. SAML handles communication between a service provider (SP) and an identity provider (IdP). The identity provider acts as an authentication and identification mechanism for service providers.
In this post, I’ll walk you through setting up your Rails application as a SAML IdP. This post is not intended to take a deep dive into the SAML protocol.
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Code Generation for Rails Utility Scripts
It seems that on every Rails project I work on, I end up writing utility scripts that make changes to the production data in some way or another. Perhaps it’s pre-loading hundreds of user accounts for a customer that wants to provide a spreadsheet of users, or populating an account with fake data that can be used for a demo, or manually fixing a data integration issue with an external system. Often, this requires parsing and processing a source file (like a CSV file). Read more on Code Generation for Rails Utility Scripts…
Active Record Aggregate Fields via Sub-Selecting Scopes
I was recently working on a piece of code from a legacy Rails application. An unusually large number of queries being run on a particular page let me know there was an N+1 query lurking.
The application was an online assessment platform dealing with assessments, questions, and responses. The question listing page was simply asking each question if it’s locked—which happens if it has any responses. So what’s the best way to query for lots of questions and their locked status? Read more on Active Record Aggregate Fields via Sub-Selecting Scopes…
Run a Local Rails Script on Heroku
Heroku provides a convenient command line interface for executing snippets of Ruby code remotely. One-liners can easily be piped into the heroku run console command. But what about much longer scripts that you write locally and want to execute in a remote Heroku environment? In this post, I’ll show you how to execute a long Ruby/Rails script in a remote Heroku environment.
Adding Google Charts to your Active Admin Application
Active Admin is a fantastic library for building an administrator interface for a Rails application. Not only does it make creating CRUD pages incredibly simple, but it also allows for custom views–something I discovered recently when I needed to create a dashboard page that included several charts.
Read more on Adding Google Charts to your Active Admin Application…
A Few Tips For Getting Started With Rails
Rails does a lot of work for you. This is often beneficial, but when it makes assumptions that aren’t right for your app, it can be frustrating. In this post, I’ll discuss a few issues that can arise when you get started creating models, along with some easy solutions to them. Oh, and before I get too far, I should note that the code here assumes you are using Rails 5.
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Testing Data Migrations in Rails
When working on a Rails project, you will inevitably need to move data around in your database. Some join table value will need to be moved into its own table or what have you. When approaching these kinds of migrations, there are two major complications: future-proofing and testing. In this post, let’s walk through an example migration.
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Uploading Files in Rails Using Paperclip and Active Admin
I recently came across a situation where I needed to be able to upload a file to a Rails server with Active Admin. I did a quick search on Google and found this post by Job, a fellow Atom.
Our use cases were a little bit different, though. He was storing the file contents directly in the database, whereas I needed to be able to uplaod a firmware image file to the server’s filesystem, parse the file name, and perform some validations on the file. I decided to use the Paperclip gem to manage the file processing and storage. Using Job’s advice on Active Admin file uploads, I expanded his example to incorporate Paperclip.
Read more on Uploading Files in Rails Using Paperclip and Active Admin…