class Form::UniqueValidator
Unique Validation¶ ↑
Reform’s own implementation for uniqueness which does not write to model
Usage¶ ↑
Pass a true boolean value to validate a field against all values available in the database: validates :title, unique: true
Options¶ ↑
Case Sensitivity¶ ↑
Case sensitivity is true by default, but can be set to false:
validates :title, unique: { case_sensitive: false }
Scope¶ ↑
A scope can be use to filter the records that need to be compare with the current value to validate. A scope array can have one to many fields define.
A scope can be define the following ways: validates :title, unique: { scope: :album_id } validates :title, unique: { scope: [:album_id] } validates :title, unique: { scope: [:album_id, …] }
All fields included in a scope must be declared as a property like this: property :album_id validates :title, unique: { scope: :album_id }
Just remove write access to the property if the field must not be change: property :album_id, writeable: false validates :title, unique: { scope: :album_id }
This use case is useful if album_id is set to a Song this way: song = album.songs.new album_id is automatically set and can’t be change by the operation
Public Instance Methods
# File lib/reform/form/validation/unique_validator.rb, line 38 def validate_each(form, attribute, value) model = form.model_for_property(attribute) original_attribute = form.options_for(attribute)[:private_name] # search for models with attribute equals to form field value query = if options[:case_sensitive] == false && value model.class.where("lower(#{original_attribute}) = ?", value.downcase) else model.class.where(original_attribute => value) end # if model persisted, query should bypass model if model.persisted? query = query.where("#{model.class.primary_key} != ?", model.id) end # apply scope if options has been declared Array(options[:scope]).each do |field| # add condition to only check unique value with the same scope query = query.where(field => form.send(field)) end form.errors.add(attribute, :taken) if query.count > 0 end