Bitwise attribute for ruby class and Rails model
- bitwise attribute + helpers, useful for storing multiple states in one place
- ActiveRecord compatible
Please read this article for some concrete examples
gem install attr_bitwise
gem 'attr_bitwise'
attr_bitwise :<name>, mapping: <values_sym> [, column_name: <column_name>]Alternatively, you can explicitly specify your states by supplying a hash with the values.
attr_bitwise :<name>, mapping: {<sym1: 1, sym2: 2, sym3: 4>} [, column_name: <column_name>]You have a website with many locales (English, French, German...) with specific content in each locale. You want your users to be able to chose which content they want to see and you want to be able to query the users by the locales they have chosen.
Start with migration
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
# [...]
t.integer :locales_value
end
end
endModel
class User < ActiveRecord::Base
include AttrBitwise
attr_bitwise :locales, mapping: [:en, :fr, :de]
scope :with_any_locales, lambda { |*locales_sym|
where(locales_value: bitwise_union(*locales_sym, 'locales'))
}
scope :with_all_locales, lambda { |*locales_sym|
where(locales_value: bitwise_intersection(*locales_sym, 'locales'))
}
end
###
# return all users who can see at least english or french content
User.with_any_locales(:en, :fr)
# return all users who can see english and french content
User.with_all_locales(:en, :fr)Examples with name = 'locales'
| Method | Return | Description |
|---|---|---|
Class#locales
|
[, ...]
|
Return values as symbols |
Class#locales=([value_or_sym, ..])
|
[, ...]
|
Given an array of values (Fixnum or Symbol) or single value (Fixnum or Symbol) add them to value. |
Class#locale == fixnum_or_sym
|
Boolean
|
Return true if value contains only Fixnum or Symbol |
Class#locale?(fixnum_or_sym)
|
Boolean
|
Return true if value contains Fixnum or Symbol |
Class#add_locale(value_or_sym)
|
Fixnum
|
Add Fixnum or Symbol to value |
Class#remove_locale(value_or_sym)
|
Fixnum
|
Remove Fixnum or Symbol to value |
Class#locales_union([value_or_sym, ..])
|
[Fixnum, ..]
|
Given an array of values (Fixnum or Symbol), return bitwise union computation Return all possible values (mask) for an union of given values |
Class#locales_intersection([value_or_sym, ..])
|
[Fixnum, ..]
|
Given an array of values (Fixnum or Symbol), return bitwise intersection computation Return all possible values (mask) for an intersection of given values |
Class::LOCALES_MAPPING
|
Hash
|
Return Symbol -> Fixnum mapping
|
Theses methods are static, so a name parameters is mandatory in order to fetch mapping
| Method | Return | Description |
|---|---|---|
Class.to_bitwise_values(object, name)
|
[Fixnum, ...]
|
Given an Object and a attribute name, return Fixnum value depending on mapping |
Class.bitwise_union([Fixnum, ..], name)
|
[Fixnum, ..]
|
Given an array of values (Fixnum or Symbol) and a attribute name, return bitwise union computation Return all possible values (mask) for an union of given values |
Class.bitwise_intersection([Fixnum, ..], name)
|
[Fixnum, ..]
|
Given an array of values (Fixnum or Symbol) and a attribute name, return bitwise intersection computation Return all possible values (mask) for an intersection of given values |
Maintainers : @wittydeveloper and @FSevaistre
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent