分离出表单对象(Form Objects)

https://github.com/angelfan/DayDayUp/blob/master/note/form_object.md#%E5%88%86%E7%A6%BB%E5%87%BA%E8%A1%A8%E5%8D%95%E5%AF%B9%E8%B1%A1form-objects

分离出表单对象(Form Objects)

step1

class SignupForm

include ActiveModel::Model
include ActiveModel::Validations

attr_accessor :user_name, department_id

validates :user_name, presence: true

def save
if valid?
# balabala
else
false
end
end

def persisted?
false
end
end

缺点:

属性没有类型

设定default 值不是很方便

step1

借助 Virtus 增加default值

class SignupForm
include ActiveModel::Model
include Virtus

# Attributes (DSL provided by Virtus)
attribute :user_name, String
attribute :department_id, Integer default: 1

# Validations
validates :user_name, presence: true

def save
if valid?
# balabala
else
false
end
end
end

resource

gem reform

gem virtus

gem simple_form_object

Creating Form Objects with ActiveModel and Virtus

Form Objects in Rails

other solution

form sharetribe

module FormUtils
module_function

# Define a form class that can be used with ActiveSupport form bindings
#
# Usage:
#
# -- in some_controller.rb --
#
# MyForm = FormUtils.define_form("MyForm", :name, :password)
#   .with_validations { validates_presence_of :name }
#
# def new
#   render locals: { form_obj: MyForm.new }
# end
#
# def create
#   myForm = MyForm.new(params[:my_form])
#   if myForm.valid?
#     ...
#
def define_form(form_name, *ks)
Class.new(Object) { |klass|
include ActiveModel::Validations
include ActiveModel::Conversion

@__keys = ks
@__form_name = form_name
@__validation_blocks = []

def self.keys
@__keys
end

def self.validation_blocks
@__validation_blocks
end

attr_reader(*ks)

def initialize(opts = {})
keys_and_values = self.class.keys
.map { |k| [k, opts[k]] }
.reject { |(k, v)| v.nil? }

keys_and_values.each { |(k, v)|
instance_variable_set("@#{k.to_s}", v)
}

instance_variable_set("@__value_hash", Hash[keys_and_values])
end

def persisted?
false
end

def to_hash
@__value_hash
end

def self.model_name
ActiveModel::Name.new(self, nil, @__form_name)
end

def self.with_validations(&block)
@__validation_blocks << block
class_exec(&block)
self
end
}
end

def merge(form_name, *form_classes)
keys = form_classes.map(&:keys).flatten
validation_blocks = form_classes.map(&:validation_blocks).flatten

form = FormUtils.define_form(form_name, *keys)

validation_blocks.each do |block|
form.with_validations(&block)
end

form
end
end

SignupForm = FormUtils.define_form("SignupForm", :user_name, :department_id)
.with_validations { validates_presence_of :user_name }