If you have decision algorithm that can be easily expressed in a table, this gem can help

Lightweight decorators using plain old Ruby objects.

DeclarativeGrid is a gem for rendering grids described in simple DSL

Creates an object from a csv row according to yml-file with mapping rules

Apply grammatical cases to words.

DecoLite is a little gem that allows you to use the provided DecoLite::Model class to dynamically create Decorator class objects. Use the DecoLite::Model class directly, or inherit from the DecoLite::Model class to create your own unique subclasses with custom functionality. DecoLite::Model includes ActiveModel::Model, so validation can be applied using ActiveModel validation helpers (https://api.rubyonrails.org/v6.1.3/classes/ActiveModel/Validations/HelperMethods.html) you're familiar with; or, you can roll your own - just like any other ActiveModel. DecoLite::Model allows you to consume a Ruby Hash that you supply via the initializer (DecoLite::Model#new) or via the DecoLite::Model#load! method. Any number of Ruby Hashes can be consumed. Your supplied Ruby Hashes are used to create attr_accessor attributes (or "fields") on the model. Each attribute created is then assigned the value from the Hash that was loaded. Again, any number of hashes can be consumed using the DecoLite::Model#load! method.

Convert JSON structures to CSVs

Convert XML to JSON with a DSL

Small add-on for Draper that decorates models before rendering.

Output formatter for the ruby Logger class

ActiveModel validation against duplicating records.

A method to use in RSpec to spot hash differences

Defaultable is an extendable class to allow easy method chaining for settings along with defaults.

Default validations for string and integer attributes

An agnostic ActiveSupport::Cache helper to enable easy caching of methods inside your classes.

Deferred Jobs

Deforest tracks the number of times your model methods are called and presents it in digestable way. You can analyse and use this data to remove unused features/code

Dehenzify

Add ActiveSupport::Inflector#dehumanize to invert humanize

An oppinionated status gem to run alongside Phobos applications