Articles by Cleiviane Costa

Service Objects: beyond fat models and skinny controllers

Service Objects are a controversial idea for several different reasons: some developers like to use them, others like to use similar patterns, and some think that they are just unnecessary because they prefer fat models.

Here at Ombu Labs we like to use service objects whenever we can, we think it's a great way to keep our controllers skinny.

In this post I would like to discuss my idea about service objects and why it's adopted by our team.

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Processing a CSV file in batch with Sidekiq

Sidekiq Pro comes with a great feature to process a collection of jobs as a batch, allowing them to be monitored as a group and executing a callback function when all the jobs are finished. This is useful when you need to load a lot of spreadsheet files into your database.

Recently, that was the case of one of Ombu Labs' clients. They needed to upload a CSV file with over 10 thousand rows of loans data, which makes processing the file synchronously impossible because the browser will time out after a few seconds. Breaking the file into smaller ones wasn't a good idea either, because it would take an unacceptable amount of time to finish. So we decided to use the Sidekiq's batch logic.

Since Sidekiq Pro wasn't an option at the time, we had the challenge of implementing the same pattern that Sidekiq Pro uses in their Batches processing. This article will show how we did it.

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Refactoring with Design Patterns - The State Pattern

In this series of code refactoring posts we are discussing how design patterns can be used to make our Ruby code beautiful, maintainable and clean.

Today I want to talk about a pattern that can be very useful when we need to control the flow of a set of events of our objects: The State Pattern a.k.a Finite State Machine.

As a developer it is common to see objects changing their state. At the beginning managing the state of an object can be as simple as having some boolean attributes where you can check if the object is in state A or B. But when the complexity increases you can end up with a number of states that are difficult to manage without breaking the SOLID principles. That is where we can implement the elegant solution provided by the State Pattern.

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Refactoring with Design Patterns - The Template Pattern

In our last article of the refactoring series we saw how design patterns can be used to make our Ruby code beautiful and clean. Design patterns are a powerful tool for any developer and a familiarity with them will lead to better code by forcing a consideration of SOLID principles.

Now let's talk about other pattern that when properly used can be very helpful: The Template Method.

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Refactoring: Clean your ruby code with design patterns

Code refactoring can be defined as “the process of introducing small and incremental changes to leave the code in a better state than it was.”. When refactoring your code you have to consider two things: no new functionality should be added and the external behavior should not be affected.

One of the biggest challenges as a Ruby on Rails Developer is to keep your code clean, simple and easy to maintain and that is why we are always refactoring our code.

There are several techniques that a developer can follow to improve their code by code refactoring, such as extract method, move method, move field, switch statements, etc. If you are not familiarized with them, please visit the Refactoring Guru site.

Another technique developers try to follow is to apply good design patterns to their code. In this post we'll try to go over some of the documented design patterns and how you can apply them to your Ruby code.

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