Aform

Aform lets you define Form Object with validatins and ability save difficult jsons or form params to models. You can create Form object with nested forms for storing has_many associations with parent model.

It was developed for rails-api and ActiveRecord.

Add this line to your application's Gemfile:

gem 'aform', '~>0.0.7'

And then execute:

$ bundle

Or install it yourself as:

$ gem install aform

Definning form is pretty simple, for instance you have posts wich have comments and comments have likes:

class PostForm < Aform::Form
  param :title, :author
  validates_presence_of :title, :author

  has_many :comments do
    param :message, :author
    validates_presence_of :message, :author

    has_many :likes do
      param :author
      validates_presence_of :author
    end
  end
end

Method param is used for adding params wich will be used for saving models. You can add any validation you need for each param.

class PostsController < ApplicationController

  def create
    form = PostForm.new(Post.new, params[:post])
    if form.save
      render json: form.model, status: :created
    else
      render json: {errors: form.errors}, status: :unprocessable_entity
    end
  end
  
  def update
    post = Post.find(params[:id])
    form = PostForm.new(post, params[:post])
    if form.save
      render json: form.model
    else
      render json: {errors: form.errors}, status: :unprocessable_entity
    end
  end

end

For deleting nested records you should set _destroy key to true in nested params:

post = {
  title: "Very Cool Post", 
  author: "John Doe",
  comments: [ {id: comment.id, _destroy: true}]
 }

Before looking up the param in a given hash, a form object will check for the presence of a method with the name of the param:

post = {
  title: "Cool Post", 
  first_author: "John Doe", 
  second_author: "Mr. Author"
}

Form Object:

class OtherPostForm < Aform::Form
  param :title, :author

  def author(attributes)
    "#{attributes[:first_author]} and #{attributes[:second_author]}"
  end
end

When you need just save method with other name you can use :model_field option:

param :first_author, model_field: :author

Aform curruntly support standart ActiveModel validations like:

validates_presence_of :title
validates :count, presence: true, inclusion: [1..100]

And ActiveRecord uniqueness validation validates_uniqueness_of or validates :title, uniqueness: true But it doesn't support yet validation with block and a symbol pointing to a method, supporting will be added in short future.

1. Fork it ( https://github.com/antonversal/aform )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request