Class: ROM::Model::Form

Inherits:
Object
  • Object
show all
Extended by:
ClassMacros, ClassInterface
Defined in:
lib/rom/rails/model/form.rb,
lib/rom/rails/model/form/error_proxy.rb,
lib/rom/rails/model/form/class_interface.rb

Overview

Abstract form class

Form objects in ROM are your top-level interface to persist data in the database. They combine many features that you know from ActiveRecord:

* params processing with sanitization and coercion
* attribute validations
* persisting data in the database

The major difference is that a ROM form object separates those responsibilities - a ROM form class has its own Attributes, Validator and ROM commands that are accessible within its instance.

Examples:

class UserForm < ROM::Model::Form
  commands users: :create

  input do
    set_model_name 'User'

    attribute :name, String
  end

  validations do
    validates :name, presence: true
  end
end

class CreateUserForm < UserForm
  attributes.timestamps :created_at

  def commit!
    users.try { users.create.call(attributes) }
  end
end

# then in your controller
CreateUserForm.build(params[:user]).save

Defined Under Namespace

Modules: ClassInterface Classes: ErrorProxy

Instance Attribute Summary collapse

Attributes included from ClassInterface

#injectible_commands, #self_commands, #validator

Instance Method Summary collapse

Methods included from ClassInterface

build, commands, inherited, inject_commands_for, input, key, validations

Constructor Details

#initialize(params = {}, options = {}) ⇒ Form

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of Form.



91
92
93
94
95
96
97
 
# File 'lib/rom/rails/model/form.rb', line 91

def initialize(params = {}, options = {})
  @params = params
  @model  = self.class.model.new(params.merge(options.slice(*self.class.key)))
  @result = nil
  @errors = ErrorProxy.new
  options.each { |key, value| instance_variable_set("@#{key}", value) }
end

Instance Attribute Details

#errors ⇒ ErrorProxy (readonly)

Return any errors with the form

Returns:



81
82
83
 
# File 'lib/rom/rails/model/form.rb', line 81

def errors
  @errors
end

#model ⇒ Object (readonly) Also known as: to_model

Return model instance representing an ActiveModel object that will be persisted or updated

Returns:

  • (Object) 


67
68
69
 
# File 'lib/rom/rails/model/form.rb', line 67

def model
  @model
end

#params ⇒ Object (readonly)

Return raw params received from the request

Returns:

  • (Object) 


59
60
61
 
# File 'lib/rom/rails/model/form.rb', line 59

def params
  @params
end

#result ⇒ Object (readonly)

Return the result of commit!

Returns:

  • (Object) 


74
75
76
 
# File 'lib/rom/rails/model/form.rb', line 74

def result
  @result
end

Instance Method Details

#attributes ⇒ Model::Attributes

Sanitize and coerce input params

This can also set default values

Returns:



149
150
151
 
# File 'lib/rom/rails/model/form.rb', line 149

def attributes
  self.class.attributes[params]
end

#commit! ⇒ Object

This method is abstract.

A specialized form object must implement this method

Raises:

  • (NotImplementedError) 


104
105
106
 
# File 'lib/rom/rails/model/form.rb', line 104

def commit!
  raise NotImplementedError, "#{self.class}#commit! must be implemented"
end

#save(*args) ⇒ self

Save a form by calling commit! and memoizing result

Returns:

  • (self) 


113
114
115
116
117
118
119
120
 
# File 'lib/rom/rails/model/form.rb', line 113

def save(*args)
  @errors.clear
  @result = commit!(*args)

  @errors.set @result.error if result.respond_to? :error

  self
end

#success? ⇒ TrueClass, FalseClass

Return whether commit was successful

Returns:

  • (TrueClass, FalseClass) 


127
128
129
 
# File 'lib/rom/rails/model/form.rb', line 127

def success?
  errors.success?
end

#validate! ⇒ Object

Trigger validation and store errors (if any)



134
135
136
137
138
139
140
 
# File 'lib/rom/rails/model/form.rb', line 134

def validate!
  @errors.clear
  validator = self.class::Validator.new(attributes)
  validator.validate

  @errors.set validator.errors
end