Xpose

Xpose provides the expose and expose! helpers to let you write smaller, cleaner controllers.

expose provides inference features to guess what you want it to be (lazy loading).
expose! is the eager loading version of expose.

Add this line to your application's Gemfile:

gem 'xpose'

And then execute:

bundle install

Here is a basic Xpose-friendly controller example:

class ArticlesController < ApplicationController
  expose :articles
  expose :article

  def index
  end

  def show
  end

  def new
  end

  def create
    if article.save
      redirect_to article, notice: 'Article was successfully created.'
    else
      render :new
    end
  end

  def edit
  end

  def update
    if article.update(article_params)
      redirect_to article, notice: 'Article was successfully updated.'
    else
      render :edit
    end
  end

  def destroy
    article.destroy
    redirect_to articles_url, notice: 'Article was successfully destroyed.'
  end

  private

  def article_params
    params.require(:article).permit(:name)
  end
end

When no value is given, expose assumes that a model can be infered from the exposed attribute name

When the name is in a plural form, it infers that the value should be a collection of said model.

expose :projects

# Is equivalent to:
expose :projects, -> { Project.all }

When the name is in a singular form, it infers that the value should be a record of said model.

Two things to know:

1. The source shall either be a previously exposed collection or a model otherwise.
2. If params[:id] exists, it calls .find(params[:id]). Otherwise, it calls .new

# Given params[:id] exists:
expose :project

# Is equivalent to:
expose :project, -> { Project.find(params[:id]) }

# Given params[:id] exists:
expose :projects, -> { Project.where(visible: true).all }
expose :project

# Is equivalent to:
expose :project, -> { projects.find(params[:id]) }

# Given params[:id] doesn't exist:
expose :project

# Is equivalent to:
expose :project, -> { Project.new }

:scope: Specify which model scope to use. Default is :all.

expose :projects, scope: :visible

# Is equivalent to:
expose :projects, -> { Project.visible }

:decorate: Choose whether the value should be decorated or not. Default is true. :decorator: Specify which decorator to use. Default is :infer.

:decorator accepts the following values:

• a class: It creates an instance of this class with the attribute as parameter (WhateverClass.new(attribute))
• a symbol: If it matches an existing method, this method is called with the attribute as paramter. Otherwise, this name is translated to a class name and if it matches an existing class, it behaves as if this class was given (see class behavior above).
• a Proc: It calls this proc
• :infer: Compatible with draper. It assumes that a ModelDecorator class exists and uses it (see class behavior above).

expose :project

# Is equivalent to:
expose :project, -> { ProjectDecorator.new(Project.find(params[:id])) }

expose :project, decorator: OpenSourceProjectDecorator

# Is equivalent to:
expose :project, -> { OpenSourceProjectDecorator.new(Project.find(params[:id])) }

In its simplest form, expose will assume that a model can be infered from the exposed attribute name. If the attribute's name is in a plural form, it assumes you want a collection (expose :projects -> @projects = Project.all). Otherwise, it assumes you want a record.

Collection example:

# This:
expose :projects

# is equivalent to:
expose :projects, -> { Project.all }

Record example:

# This:
expose :project

# is equivalent to:
expose :projects, -> { Project.all }

Default values: expose :name, :infer, scope: :all, decorate: true, decorator: :infer

Examples:

expose :articles
expose :articles, scope: :visible
expose :article
expose :forthy_two, -> { 42 }, decorate: false
expose :bob, -> { "Bob" }, decorator: -> { |v| v.length }

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/yoones/xpose. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the Xpose project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.