#
# Pagination is included automatically for all controllers.
#
- # For help rendering pagination links, see
+ # For help rendering pagination links, see
# ActionView::Helpers::PaginationHelper.
#
# ==== Automatic pagination for every action in a controller
#
- # class PersonController < ApplicationController
+ # class PersonController < ApplicationController
# model :person
#
# paginate :people, :order => 'last_name, first_name',
# :per_page => 20
- #
+ #
# # ...
# end
#
# Each action in this controller now has access to a <tt>@people</tt>
# instance variable, which is an ordered collection of model objects for the
- # current page (at most 20, sorted by last name and first name), and a
+ # current page (at most 20, sorted by last name and first name), and a
# <tt>@person_pages</tt> Paginator instance. The current page is determined
# by the <tt>params[:page]</tt> variable.
#
# and <tt>@people</tt> for a single action, and uses the default of 10 items
# per page.
#
- # ==== Custom/"classic" pagination
+ # ==== Custom/"classic" pagination
#
# def list
# @person_pages = Paginator.new self, Person.count, 10, params[:page]
- # @people = Person.find :all, :order => 'last_name, first_name',
+ # @people = Person.find :all, :order => 'last_name, first_name',
# :limit => @person_pages.items_per_page,
# :offset => @person_pages.current.offset
# end
- #
- # Explicitly creates the paginator from the previous example and uses
+ #
+ # Explicitly creates the paginator from the previous example and uses
# Paginator#to_sql to retrieve <tt>@people</tt> from the model.
#
module Pagination
- unless const_defined?(:OPTIONS)
+ if const_defined?(:OPTIONS)
+ DEFAULT_OPTIONS[:group] = nil
+ else
# A hash holding options for controllers using macro-style pagination
- OPTIONS = Hash.new
-
+ OPTIONS = {}.freeze
+
# The default options for pagination
DEFAULT_OPTIONS = {
:class_name => nil,
:singular_name => nil,
- :per_page => 10,
+ :per_page => 10,
:conditions => nil,
- :order_by => nil,
- :order => nil,
- :join => nil,
- :joins => nil,
- :count => nil,
- :include => nil,
- :select => nil,
- :group => nil,
- :parameter => 'page'
- }
- else
- DEFAULT_OPTIONS[:group] = nil
+ :order_by => nil,
+ :order => nil,
+ :join => nil,
+ :joins => nil,
+ :count => nil,
+ :include => nil,
+ :select => nil,
+ :group => nil,
+ :parameter => "page"
+ }.freeze
end
-
- def self.included(base) #:nodoc:
+
+ def self.included(base) # :nodoc:
super
base.extend(ClassMethods)
end
-
- def self.validate_options!(collection_id, options, in_action) #:nodoc:
- options.merge!(DEFAULT_OPTIONS) {|key, old, new| old}
+
+ def self.validate_options!(collection_id, options, in_action) # :nodoc:
+ options.merge!(DEFAULT_OPTIONS) { |_key, old, _new| old }
valid_options = DEFAULT_OPTIONS.keys
valid_options << :actions unless in_action
-
+
unknown_option_keys = options.keys - valid_options
- raise ActionController::ActionControllerError,
- "Unknown options: #{unknown_option_keys.join(', ')}" unless
- unknown_option_keys.empty?
+ unless unknown_option_keys.empty?
+ raise ActionController::ActionControllerError,
+ "Unknown options: #{unknown_option_keys.join(', ')}"
+ end
options[:singular_name] ||= ActiveSupport::Inflector.singularize(collection_id.to_s)
- options[:class_name] ||= ActiveSupport::Inflector.camelize(options[:singular_name])
+ options[:class_name] ||= ActiveSupport::Inflector.camelize(options[:singular_name])
end
# Returns a paginator and a collection of Active Record model instances
# <tt>:singular_name</tt>:: the singular name to use, if it can't be inferred by singularizing the collection name
# <tt>:class_name</tt>:: the class name to use, if it can't be inferred by
# camelizing the singular name
- # <tt>:per_page</tt>:: the maximum number of items to include in a
+ # <tt>:per_page</tt>:: the maximum number of items to include in a
# single page. Defaults to 10
# <tt>:conditions</tt>:: optional conditions passed to Model.find(:all, *params) and
# Model.count
#
# <tt>:group</tt>:: :group parameter passed to Model.find(:all, *params). It forces the use of DISTINCT instead of plain COUNT to come up with the total number of records
#
- def paginate(collection_id, options={})
+ def paginate(collection_id, options = {})
Pagination.validate_options!(collection_id, options, true)
paginator_and_collection_for(collection_id, options)
end
- # These methods become class methods on any controller
+ # These methods become class methods on any controller
module ClassMethods
- # Creates a +before_filter+ which automatically paginates an Active
+ # Creates a +before_action+ which automatically paginates an Active
# Record model for all actions in a controller (or certain actions if
# specified with the <tt>:actions</tt> option).
#
- # +options+ are the same as PaginationHelper#paginate, with the addition
+ # +options+ are the same as PaginationHelper#paginate, with the addition
# of:
# <tt>:actions</tt>:: an array of actions for which the pagination is
# active. Defaults to +nil+ (i.e., every action)
- def paginate(collection_id, options={})
+ def paginate(collection_id, options = {})
Pagination.validate_options!(collection_id, options, false)
module_eval do
- before_filter :create_paginators_and_retrieve_collections
- OPTIONS[self] ||= Hash.new
+ before_action :create_paginators_and_retrieve_collections
+ OPTIONS[self] ||= {}
OPTIONS[self][collection_id] = options
end
end
end
- def create_paginators_and_retrieve_collections #:nodoc:
+ protected
+
+ def create_paginators_and_retrieve_collections # :nodoc:
Pagination::OPTIONS[self.class].each do |collection_id, options|
- next unless options[:actions].include? action_name if
- options[:actions]
+ next if options[:actions]&.exclude?(action_name)
- paginator, collection =
+ paginator, collection =
paginator_and_collection_for(collection_id, options)
paginator_name = "@#{options[:singular_name]}_pages"
- self.instance_variable_set(paginator_name, paginator)
+ instance_variable_set(paginator_name, paginator)
- collection_name = "@#{collection_id.to_s}"
- self.instance_variable_set(collection_name, collection)
+ collection_name = "@#{collection_id}"
+ instance_variable_set(collection_name, collection)
end
end
-
+
# Returns the total number of items in the collection to be paginated for
# the +model+ and given +conditions+. Override this method to implement a
# custom counter.
def count_collection_for_pagination(model, options)
- model.count(:conditions => options[:conditions],
- :joins => options[:join] || options[:joins],
- :include => options[:include],
- :select => (options[:group] ? "DISTINCT #{options[:group]}" : options[:count]))
+ collection = model.joins(options[:join] || options[:joins])
+ collection = collection.where(options[:conditions])
+ collection = collection.includes(options[:include])
+
+ if options[:group]
+ collection = collection.select(options[:group]).distinct
+ elsif options[:count]
+ collection = collection.select(options[:count])
+ end
+
+ collection.count
end
-
+
# Returns a collection of items for the given +model+ and +options[conditions]+,
# ordered by +options[order]+, for the current page in the given +paginator+.
# Override this method to implement a custom finder.
def find_collection_for_pagination(model, options, paginator)
- model.find(:all, :conditions => options[:conditions],
- :order => options[:order_by] || options[:order],
- :joins => options[:join] || options[:joins], :include => options[:include],
- :select => options[:select], :limit => options[:per_page],
- :group => options[:group], :offset => paginator.current.offset)
+ collection = model.joins(options[:join] || options[:joins])
+ collection = collection.where(options[:conditions])
+ collection = collection.order(options[:order_by] || options[:order])
+ collection = collection.includes(options[:include])
+ collection = collection.group(options[:group])
+ collection = collection.select(options[:select]) if options[:select]
+
+ collection.offset(paginator.current.offset).limit(options[:per_page])
end
-
- protected :create_paginators_and_retrieve_collections,
- :count_collection_for_pagination,
- :find_collection_for_pagination
- def paginator_and_collection_for(collection_id, options) #:nodoc:
+ private
+
+ def paginator_and_collection_for(_collection_id, options) # :nodoc:
klass = options[:class_name].constantize
page = params[options[:parameter]]
count = count_collection_for_pagination(klass, options)
paginator = Paginator.new(self, count, options[:per_page], page)
collection = find_collection_for_pagination(klass, options, paginator)
-
- return paginator, collection
+
+ [paginator, collection]
end
-
- private :paginator_and_collection_for
# A class representing a paginator for an Active Record collection.
class Paginator
# Raises ArgumentError if items_per_page is out of bounds (i.e., less
# than or equal to zero). The page CGI parameter for links defaults to
# "page" and can be overridden with +page_parameter+.
- def initialize(controller, item_count, items_per_page, current_page=1)
- raise ArgumentError, 'must have at least one item per page' if
+ def initialize(controller, item_count, items_per_page, current_page = 1)
+ raise ArgumentError, "must have at least one item per page" if
items_per_page <= 0
@controller = controller
@item_count = item_count || 0
@items_per_page = items_per_page
@pages = {}
-
+
self.current_page = current_page
end
attr_reader :controller, :item_count, :items_per_page
-
+
# Sets the current page number of this paginator. If +page+ is a Page
- # object, its +number+ attribute is used as the value; if the page does
+ # object, its +number+ attribute is used as the value; if the page does
# not belong to this Paginator, an ArgumentError is raised.
def current_page=(page)
- if page.is_a? Page
- raise ArgumentError, 'Page/Paginator mismatch' unless
- page.paginator == self
- end
+ raise ArgumentError, "Page/Paginator mismatch" if page.is_a?(Page) && page.paginator != self
+
page = page.to_i
- @current_page_number = has_page_number?(page) ? page : 1
+ @current_page_number = contains_page?(page) ? page : 1
end
# Returns a Page object representing this paginator's current page.
def current_page
@current_page ||= self[@current_page_number]
end
- alias current :current_page
+ alias current current_page
# Returns a new Page representing the first page in this paginator.
def first_page
@first_page ||= self[1]
end
- alias first :first_page
+ alias first first_page
# Returns a new Page representing the last page in this paginator.
def last_page
- @last_page ||= self[page_count]
+ @last_page ||= self[page_count]
end
- alias last :last_page
+ alias last last_page
# Returns the number of pages in this paginator.
def page_count
- @page_count ||= @item_count.zero? ? 1 :
- (q,r=@item_count.divmod(@items_per_page); r==0? q : q+1)
+ @page_count ||= if @item_count.zero?
+ 1
+ else
+ q, r = @item_count.divmod(@items_per_page)
+ r.zero? ? q : q + 1
+ end
end
- alias length :page_count
+ alias length page_count
# Returns true if this paginator contains the page of index +number+.
- def has_page_number?(number)
- number >= 1 and number <= page_count
+ def contains_page?(number)
+ number >= 1 && number <= page_count
end
# Returns a new Page representing the page with the given index
end
# Successively yields all the paginator's pages to the given block.
- def each(&block)
+ def each(&)
page_count.times do |n|
- yield self[n+1]
+ yield self[n + 1]
end
end
def initialize(paginator, number)
@paginator = paginator
@number = number.to_i
- @number = 1 unless @paginator.has_page_number? @number
+ @number = 1 unless @paginator.contains_page? @number
end
attr_reader :paginator, :number
- alias to_i :number
- # Compares two Page objects and returns true when they represent the
+ alias to_i number
+
+ # Compares two Page objects and returns true when they represent the
# same page (i.e., their paginators are the same and they have the
# same page number).
- def ==(page)
- return false if page.nil?
- @paginator == page.paginator and
- @number == page.number
+ def ==(other)
+ return false if other.nil?
+
+ @paginator == other.paginator &&
+ @number == other.number
end
# Compares two Page objects and returns -1 if the left-hand page comes
# before the right-hand page, 0 if the pages are equal, and 1 if the
# left-hand page comes after the right-hand page. Raises ArgumentError
# if the pages do not belong to the same Paginator object.
- def <=>(page)
- raise ArgumentError unless @paginator == page.paginator
- @number <=> page.number
+ def <=>(other)
+ raise ArgumentError unless @paginator == other.paginator
+
+ @number <=> other.number
end
# Returns the item offset for the first item in this page.
def offset
@paginator.items_per_page * (@number - 1)
end
-
+
# Returns the number of the first item displayed.
def first_item
offset + 1
end
-
+
# Returns the number of the last item displayed.
def last_item
[@paginator.items_per_page * @number, @paginator.item_count].min
# Returns a new Page object representing the page just before this
# page, or nil if this is the first page.
def previous
- if first? then nil else @paginator[@number - 1] end
+ first? ? nil : @paginator[@number - 1]
end
# Returns a new Page object representing the page just after this
# page, or nil if this is the last page.
def next
- if last? then nil else @paginator[@number + 1] end
+ last? ? nil : @paginator[@number + 1]
end
- # Returns a new Window object for this page with the specified
+ # Returns a new Window object for this page with the specified
# +padding+.
- def window(padding=2)
+ def window(padding = 2)
Window.new(self, padding)
end
def to_sql
[@paginator.items_per_page, offset]
end
-
- def to_param #:nodoc:
+
+ def to_param # :nodoc:
@number.to_s
end
end
class Window
# Creates a new Window object for the given +page+ with the specified
# +padding+.
- def initialize(page, padding=2)
+ def initialize(page, padding = 2)
@paginator = page.paginator
@page = page
self.padding = padding
end
- attr_reader :paginator, :page
+ attr_reader :paginator, :page, :padding, :first, :last
# Sets the window's padding (the number of pages on either side of the
# window page).
def padding=(padding)
- @padding = padding < 0 ? 0 : padding
+ @padding = padding.negative? ? 0 : padding
# Find the beginning and end pages of the window
- @first = @paginator.has_page_number?(@page.number - @padding) ?
- @paginator[@page.number - @padding] : @paginator.first
- @last = @paginator.has_page_number?(@page.number + @padding) ?
- @paginator[@page.number + @padding] : @paginator.last
+ @first = if @paginator.contains_page?(@page.number - @padding)
+ @paginator[@page.number - @padding]
+ else
+ @paginator.first
+ end
+ @last = if @paginator.contains_page?(@page.number + @padding)
+ @paginator[@page.number + @padding]
+ else
+ @paginator.last
+ end
end
- attr_reader :padding, :first, :last
# Returns an array of Page objects in the current window.
def pages
- (@first.number..@last.number).to_a.collect! {|n| @paginator[n]}
+ (@first.number..@last.number).to_a.collect! { |n| @paginator[n] }
end
- alias to_a :pages
+ alias to_a pages
end
end
-
end
end