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Ransack is a rewrite of [MetaSearch] (https://github.com/activerecord-hackery/meta_search) created by Ernie Miller and maintained by Ryan Bigg, Jon Atack and a great group of [contributors] (https://github.com/activerecord-hackery/ransack/graphs/contributors). While it supports many of the same features as MetaSearch, its underlying implementation differs greatly from MetaSearch, and backwards compatibility is not a design goal.
Ransack enables the creation of both simple and advanced search forms for your Ruby on Rails application (demo source code here). If you're looking for something that simplifies query generation at the model or controller layer, you're probably not looking for Ransack (or MetaSearch, for that matter). Try Squeel instead.
If you're viewing this at github.com/activerecord-hackery/ransack, you're reading the documentation for the master branch with the latest features. [View documentation for the last release (1.6.3).] (https://github.com/activerecord-hackery/ransack/tree/v1.6.3)
Ransack is compatible with Rails 3 and 4 (including 4.2) on Ruby 1.9 and later. We try to keep it functioning with Rails master too, although frequent changes in Arel and Active Record make that a moving target. Ransack works out-of-the-box with Active Record and features new support for Mongoid 4.0 (without associations, further details below). If you are on Ruby 1.8, you may need to use an earlier version of Ransack like 1.3.0.
In your Gemfile, for the last officially released Ransack gem:
gem 'ransack'Or, if you would like to use the latest updates, use the master branch:
gem 'ransack', github: 'activerecord-hackery/ransack'The other branches (rails-4, rails-4.1, and rails-4.2) were each used for
developing and running Ransack with the latest upcoming version of Rails at the
time. They are smaller and possibly slightly faster because they do not have to
support previous versions of Rails and Active Record. Once support for that
Rails version is merged from the branch into Ransack master, the branch is no
longer actively maintained -- unless the open source community submits pull
requests to maintain them. You are welcome to do so!
To use one of the branches, for example the rails-4.1 branch:
gem 'ransack', github: 'activerecord-hackery/ransack', branch: 'rails-4.1'If you are using Rails master, be advised that Ransack master does not yet work with the breaking changes in Rails master and Arel master added since December 2014. The most recent working commits are:
gem 'rails', github: 'rails/rails', ref: '266ff70'
gem 'arel', github: 'rails/arel', ref: '008445d'Ransack can be used in one of two modes, simple or advanced.
This mode works much like MetaSearch, for those of you who are familiar with it, and requires very little setup effort.
If you're coming from MetaSearch, things to note:
-
The default param key for search params is now
:q, instead of:search. This is primarily to shorten query strings, though advanced queries (below) will still run afoul of URL length limits in most browsers and require a switch to HTTP POST requests. This key is [configurable] (https://github.com/activerecord-hackery/ransack/wiki/Configuration). -
form_foris nowsearch_form_for, and validates that a Ransack::Search object is passed to it. -
Common ActiveRecord::Relation methods are no longer delegated by the search object. Instead, you will get your search results (an ActiveRecord::Relation in the case of the ActiveRecord adapter) via a call to
Ransack#result. -
If passed
distinct: true,resultwill generate aSELECT DISTINCTto avoid returning duplicate rows, even if conditions on a join would otherwise result in some. It generates the same SQL as callinguniqon the relation.
Please note that for many databases, a sort on an associated table's columns
may result in invalid SQL with distinct: true -- in those cases, you're on
your own, and will need to modify the result as needed to allow these queries
to work.
If distinct: true or uniq is causing invalid SQL, another way to remove
duplicates is to call to_a.uniq on the collection at the end (see the next
section below) -- with the caveat that the de-duping is taking place in Ruby
instead of in SQL, which is potentially slower and uses more memory, and that
it may display awkwardly with pagination if the number of results is greater
than the page size.
####In your controller
def index
@q = Person.ransack(params[:q])
@people = @q.result(distinct: true)
endor without distinct:true, for sorting on an associated table's columns (in
this example, with preloading each Person's Articles and pagination):
def index
@q = Person.ransack(params[:q])
@people = @q.result.includes(:articles).page(params[:page])
# or use `to_a.uniq` to remove duplicates (can also be done in the view):
@people = @q.result.includes(:articles).page(params[:page]).to_a.uniq
end####In your view
The two primary Ransack view helpers are search_form_for and sort_link,
which are defined in
Ransack::Helpers::FormHelper.
#####Ransack's search_form_for helper replaces form_for for creating the view search form:
<%= search_form_for @q do |f| %>
# Search if the name field contains...
<%= f.label :name_cont %>
<%= f.search_field :name_cont %>
# Search if an associated articles.title starts with...
<%= f.label :articles_title_start %>
<%= f.search_field :articles_title_start %>
# Attributes may be chained. Search multiple attributes for one value...
<%= f.label :name_or_description_or_email_or_articles_title_cont %>
<%= f.search_field :name_or_description_or_email_or_articles_title_cont %>
<%= f.submit %>
<% end %>cont (contains) and start (starts with) are just two of the available
search predicates. See [Constants]
(https://github.com/activerecord-hackery/ransack/blob/master/lib/ransack/constants.rb)
for a full list and the [wiki]
(https://github.com/activerecord-hackery/ransack/wiki/Basic-Searching)
for more information.
The search_form_for answer format can be set like this:
<%= search_form_for(@q, format: :pdf) do |f| %>
<%= search_form_for(@q, format: :json) do |f| %>#####Ransack's sort_link helper creates table headers that are sortable links:
<%= sort_link(@q, :name) %>Additional options can be passed after the column attribute, like a different column title or a default sort order:
<%= sort_link(@q, :name, 'Last Name', default_order: :desc) %>With a polymorphic association, you may need to specify the name of the link
explicitly to avoid an uninitialized constant Model::Xxxable error (see issue
#421):
<%= sort_link(@q, :xxxable_of_Ymodel_type_some_attribute, 'Attribute Name') %>You can also sort on multiple fields by specifying an ordered array:
<%= sort_link(@q, :last_name, [:last_name, 'first_name asc'], 'Last Name') %>In the example above, clicking the link will sort by last_name and then
first_name. Specifying the sort direction on a field in the array tells
Ransack to always sort that particular field in the specified direction.
Multiple default_order fields may also be specified with a hash:
<%= sort_link(@q, :last_name, %i(last_name first_name),
default_order: { last_name: 'asc', first_name: 'desc' }) %>This example toggles the sort directions of both fields, by default
initially sorting the last_name field by ascending order, and the
first_name field by descending order.
The sort link may be displayed without the order indicator arrow by passing
hide_indicator: true:
<%= sort_link(@q, :name, hide_indicator: true) %>"Advanced" searches (ab)use Rails' nested attributes functionality in order to generate complex queries with nested AND/OR groupings, etc. This takes a bit more work but can generate some pretty cool search interfaces that put a lot of power in the hands of your users. A notable drawback with these searches is that the increased size of the parameter string will typically force you to use the HTTP POST method instead of GET. :(
This means you'll need to tweak your routes...
resources :people do
collection do
match 'search' => 'people#search', via: [:get, :post], as: :search
end
end... and add another controller action ...
def search
index
render :index
end... and update your search_form_for line in the view ...
<%= search_form_for @q, url: search_people_path,
html: { method: :post } do |f| %>Once you've done so, you can make use of the helpers in Ransack::Helpers::FormBuilder to construct much more complex search forms, such as the one on the demo page (source code here).
Ransack will try to to make the class method #search available in your
models, but if #search has already been defined elsewhere, you can always use
the default #ransack class method. So the following are equivalent:
Article.ransack(params[:q])
Article.search(params[:q])Users have reported issues of #search name conflicts with other gems, so
the #search method alias might be deprecated in the next major version of
Ransack (2.0). It's advisable to use the default #ransack instead.
For now, if Ransack's #search method conflicts with the name of another
method named search in your code or another gem, you may resolve it either by
patching the extended class_method in Ransack::Adapters::ActiveRecord::Base
to remove the line alias :search :ransack unless base.respond_to? :search, or
by placing the following line in your Ransack initializer file at
config/initializers/ransack.rb:
Ransack::Adapters::ActiveRecord::Base.class_eval('remove_method :search')You can easily use Ransack to search for objects in has_many and belongs_to
associations.
Given these associations...
class Employee < ActiveRecord::Base
belongs_to :supervisor
# has attributes first_name:string and last_name:string
end
class Department < ActiveRecord::Base
has_many :supervisors
# has attribute title:string
end
class Supervisor < ActiveRecord::Base
belongs_to :department
has_many :employees
# has attribute last_name:string
end... and a controller...
class SupervisorsController < ApplicationController
def index
@q = Supervisor.ransack(params[:q])
@supervisors = @q.result.includes(:department, :employees)
end
end... you might set up your form like this...
<%= search_form_for @q do |f| %>
<%= f.label :last_name_cont %>
<%= f.search_field :last_name_cont %>
<%= f.label :department_title_cont %>
<%= f.search_field :department_title_cont %>
<%= f.label :employees_first_name_or_employees_last_name_cont %>
<%= f.search_field :employees_first_name_or_employees_last_name_cont %>
<%= f.submit "search" %>
<% end %>
...
<%= content_tag :table do %>
<%= content_tag :th, sort_link(@q, :last_name) %>
<%= content_tag :th, sort_link(@q, 'departments.title') %>
<%= content_tag :th, sort_link(@q, 'employees.last_name') %>
<% end %>Please note that in a sort link, the association is expressed as an SQL string
('employees.last_name') with a pluralized table name, instead of the symbol
:employee_last_name syntax with a class#underscore table name used for
Ransack objects elsewhere.
The main premise behind Ransack is to provide access to
Arel predicate methods. Ransack provides special methods, called
ransackers, for creating additional search functions via Arel. More
information about ransacker methods can be found [here in the wiki]
(https://github.com/activerecord-hackery/ransack/wiki/Using-Ransackers).
Feel free to contribute working ransacker code examples to the wiki!
By default, searching and sorting are authorized on any column of your model and no class methods/scopes are whitelisted.
Ransack adds four methods to ActiveRecord::Base that you can redefine as
class methods in your models to apply selective authorization:
ransackable_attributes, ransackable_associations, ransackable_scopes and
ransortable_attributes.
Here is how these four methods are implemented in Ransack:
# `ransackable_attributes` by default returns all column names
# and any defined ransackers as an array of strings.
# For overriding with a whitelist array of strings.
#
def ransackable_attributes(auth_object = nil)
column_names + _ransackers.keys
end
# `ransackable_associations` by default returns the names
# of all associations as an array of strings.
# For overriding with a whitelist array of strings.
#
def ransackable_associations(auth_object = nil)
reflect_on_all_associations.map { |a| a.name.to_s }
end
# `ransortable_attributes` by default returns the names
# of all attributes available for sorting as an array of strings.
# For overriding with a whitelist array of strings.
#
def ransortable_attributes(auth_object = nil)
ransackable_attributes(auth_object)
end
# `ransackable_scopes` by default returns an empty array
# i.e. no class methods/scopes are authorized.
# For overriding with a whitelist array of *symbols*.
#
def ransackable_scopes(auth_object = nil)
[]
endAny values not returned from these methods will be ignored by Ransack, i.e. they are not authorized.
All four methods can receive a single optional parameter, auth_object. When
you call the search or ransack method on your model, you can provide a value
for an auth_object key in the options hash which can be used by your own
overridden methods.
Here is an example that puts all this together, adapted from
[this blog post by Ernie Miller]
(http://erniemiller.org/2012/05/11/why-your-ruby-class-macros-might-suck-mine-did/).
In an Article model, add the following ransackable_attributes class method
(preferably private):
class Article < ActiveRecord::Base
private
def self.ransackable_attributes(auth_object = nil)
if auth_object == :admin
# whitelist all attributes for admin
super
else
# whitelist only the title and body attributes for other users
super & %w(title body)
end
end
endHere is example code for the articles_controller:
class ArticlesController < ApplicationController
def index
@q = Article.ransack(params[:q], auth_object: set_ransack_auth_object)
@articles = @q.result
end
private
def set_ransack_auth_object
current_user.admin? ? :admin : nil
end
endTrying it out in rails console:
> Article
=> Article(id: integer, person_id: integer, title: string, body: text)
> Article.ransackable_attributes
=> ["title", "body"]
> Article.ransackable_attributes(:admin)
=> ["id", "person_id", "title", "body"]
> Article.ransack(id_eq: 1).result.to_sql
=> SELECT "articles".* FROM "articles" # Note that search param was ignored!
> Article.ransack({ id_eq: 1 }, { auth_object: nil }).result.to_sql
=> SELECT "articles".* FROM "articles" # Search param still ignored!
> Article.ransack({ id_eq: 1 }, { auth_object: :admin }).result.to_sql
=> SELECT "articles".* FROM "articles" WHERE "articles"."id" = 1That's it! Now you know how to whitelist/blacklist various elements in Ransack.
Continuing on from the preceding section, searching by scopes requires defining
a whitelist of ransackable_scopes on the model class. The whitelist should be
an array of symbols. By default, all class methods (e.g. scopes) are ignored.
Scopes will be applied for matching true values, or for given values if the
scope accepts a value:
class Employee < ActiveRecord::Base
scope :active, ->(boolean = true) { where(active: boolean) }
scope :salary_gt, ->(amount) { where('salary > ?', amount) }
# Scopes are just syntactical sugar for class methods, which may also be used:
def self.hired_since(date)
where('start_date >= ?', date)
end
private
def self.ransackable_scopes(auth_object = nil)
if auth_object.try(:admin?)
# allow admin users access to all three methods
%i(active hired_since salary_gt)
else
# allow other users to search on active and hired_since only
%i(active hired_since)
end
end
end
Employee.ransack({ active: true, hired_since: '2013-01-01' })
Employee.ransack({ salary_gt: 100_000 }, { auth_object: current_user })If the true value is being passed via url params or by some other mechanism
that will convert it to a string (i.e. active: 'true' instead of
active: true), the true value will not be passed to the scope. If you want
to pass a 'true' string to the scope, you should wrap it in an array (i.e.
active: ['true']).
Scopes are a recent addition to Ransack and currently have a few caveats: First, a scope involving child associations needs to be defined in the parent table model, not in the child model. Second, scopes with an array as an argument are not easily usable yet, because the array currently needs to be wrapped in an array to function (see this issue), which is not compatible with Ransack form helpers. For this use case, it may be better for now to use [ransackers] (https://github.com/activerecord-hackery/ransack/wiki/Using-Ransackers) instead, where feasible. Pull requests with solutions and tests are welcome!
The default AND grouping can be changed to OR by adding m: 'or' to the
query hash.
You can easily try it in your controller code by changing params[:q] in the
index action to params[:q].try(:merge, m: 'or') as follows:
def index
@q = Artist.ransack(params[:q].try(:merge, m: 'or'))
@artists = @q.result
endNormally, if you wanted users to be able to toggle between AND and OR
query grouping, you would probably set up your search form so that m was in
the URL params hash, but here we assigned m manually just to try it out
quickly.
Alternatively, trying it in the Rails console:
artists = Artist.ransack(name_cont: 'foo', style_cont: 'bar', m: 'or')
=> Ransack::Search<class: Artist, base: Grouping <conditions: [
Condition <attributes: ["name"], predicate: cont, values: ["foo"]>,
Condition <attributes: ["style"], predicate: cont, values: ["bar"]>
], combinator: or>>
artists.result.to_sql
=> "SELECT \"artists\".* FROM \"artists\"
WHERE ((\"artists\".\"name\" ILIKE '%foo%'
OR \"artists\".\"style\" ILIKE '%bar%'))"The combinator becomes or instead of the default and, and the SQL query
becomes WHERE...OR instead of WHERE...AND.
This works with associations as well. Imagine an Artist model that has many Memberships, and many Musicians through Memberships:
artists = Artist.ransack(name_cont: 'foo', musicians_email_cont: 'bar', m: 'or')
=> Ransack::Search<class: Artist, base: Grouping <conditions: [
Condition <attributes: ["name"], predicate: cont, values: ["foo"]>,
Condition <attributes: ["musicians_email"], predicate: cont, values: ["bar"]>
], combinator: or>>
artists.result.to_sql
=> "SELECT \"artists\".* FROM \"artists\"
LEFT OUTER JOIN \"memberships\"
ON \"memberships\".\"artist_id\" = \"artists\".\"id\"
LEFT OUTER JOIN \"musicians\"
ON \"musicians\".\"id\" = \"memberships\".\"musician_id\"
WHERE ((\"artists\".\"name\" ILIKE '%foo%'
OR \"musicians\".\"email\" ILIKE '%bar%'))"If you would like to combine the Ransack and SimpleForm form builders, set the
RANSACK_FORM_BUILDER environment variable before Rails boots up, e.g. in
config/application.rb before require 'rails/all' as shown below (and add
gem 'simple_form' in your Gemfile).
require File.expand_path('../boot', __FILE__)
ENV['RANSACK_FORM_BUILDER'] = '::SimpleForm::FormBuilder'
require 'rails/all'Ransack translation files are available in Ransack::Locale. You may also be interested in one of the many translations for Ransack available at http://www.localeapp.com/projects/2999.
Predicate and attribute translations in forms may be specified as follows (see the translation files in Ransack::Locale for more examples):
locales/en.yml:
en:
ransack:
asc: ascending
desc: descending
predicates:
cont: contains
not_cont: not contains
start: starts with
end: ends with
gt: greater than
lt: less than
attributes:
person:
name: Full Name
article:
title: Article Title
body: Main ContentAttribute names may also be changed globally, or under activerecord:
en:
attributes:
model_name:
model_field1: field name1
model_field2: field name2
activerecord:
attributes:
namespace/article:
title: AR Namespaced Title
namespace_article:
title: Old Ransack Namespaced TitleRansack now works with Mongoid in the same way as Active Record, except that
with Mongoid, associations are not currently supported. A demo app may be found
here and the demo source code is
here. A result method
called on a ransack search returns a Mongoid::Criteria object:
@q = Person.ransack(params[:q])
@people = @q.result # => Mongoid::Criteria
# or you can add more Mongoid queries
@people = @q.result.active.order_by(updated_at: -1).limit(10)Ransack attempts to follow semantic versioning in the format of x.y.z, where:
x stands for a major version (new features that are not backward-compatible).
y stands for a minor version (new features that are backward-compatible).
z stands for a patch (bug fixes).
In other words: Major.Minor.Patch.
To support the project:
- Use Ransack in your apps, and let us know if you encounter anything that's broken or missing. A failing spec to demonstrate the issue is awesome. A pull request with passing tests is even better!
- Before filing an issue or pull request, be sure to read and follow the Contributing Guide.
- Please use Stack Overflow or other sites for questions or discussion not directly related to bug reports, pull requests, or documentation improvements.
- Spread the word on Twitter, Facebook, and elsewhere if Ransack's been useful to you. The more people who are using the project, the quicker we can find and fix bugs!
Copyright © 2011-2014 Ernie Miller