Simply add following to your gemfile
properties column in the model you would like to use properties within, i.e.
rails g migration AddPropertiesToUsers properties:hstore
Apply your migration
Finally, describe your properties in your model file
class User < ActiveRecord::Base include ActiveRecord::HstoreProperties properties 'third_name', 'some_cool_feature' => :boolean, 'comments' => :counter, 'age' => :number end
By default, all your properties are of type String. There are number of other property types available though...
More will come in near future...
All properties can be retrieved just as they are written into hstore column, by suffixing them with
User.last.third_name_property #=> "Jack"
Boolean properties, can be additionaly retrieved by using
? suffixes, that will cast them to boolean value, i.e.
User.last.some_cool_feature_enabled? #=> true User.last.some_cool_feature? #=> true
What is more, you can toggle value of boolean property using
_lower! suffixes, e.g.
User.last.some_cool_feature_enable! #=> Changes property to true User.last.some_cool_feature_raise! #=> Changes property to true User.last.some_cool_feature_disable! #=> Changes property to false User.last.some_cool_feature_lower! #=> Changes property to false
Counter properties, can be retrieved by using
_count suffix, that will cast them to integer value, i.e.
User.last.comments_count #=> 10
What is more, it is possible to bump counter properties, i.e. following line will increment comments property by 1
Translation kind of property allows you to store translated strings in properties column. The simplest way to store translation is just assign it a value, and it will save it in current locale, e.g.
class Category < ActiveRecord::Base include ActiveRecord::HstoreProperties properties 'caption' => :translation end c = Category.last c. = "Nice product" #this will save 'Nice product' into caption_en property c.save c. #this will retrieve 'Nice product' from caption_en property
You can always enforce in which locale you would like to store property, by suffixing it with any locale code available in
c = Category.last c. = "Nice product" c. = "Fint produkt" c.save c. #=> "Nice product" c. #=> "Fint produkt" I18n.locale = :nb-NO' c. #=> "Fint produkt"
Updating through forms
You obviously need to add
:properties to yours
Below is an example of building appropriate fields dynamically with formtastic
<%= semantic_form_for @user do |f| %> <%= f.first_name %> <%= f.fields_for :properties, OpenStruct.new(@user.properties) do |builder| %> <% User.properties.each do |property| %> <%= builder.input property.name, property.formtastic_options %> <% end %> <% end %> <%= f.submit %> <% end %>
If most of your properties are of the same type, but other than string, you can overwrite
default_property_klass to make other type default, i.e.
class User < ActiveRecord::Base #... def self.default_property_klass ActiveRecord::Properties::BooleanProperty end end
When to use?
- If you consider adding redundant column to your table, that will only sometimes store any data
- If you would like to make particular model "configurable"
- If you will not likely perform queries on specific field but mostly read from it directly