Class: PaginationHelper::Paginator::Page

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
app/helpers/pagination_helper.rb

Overview

A class representing a single page in a paginator.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(paginator, number) ⇒ Page

Creates a new Page for the given paginator with the index number.

If number is not in the range of valid page numbers or is not a number at all, it defaults to 1.



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# File 'app/helpers/pagination_helper.rb', line 370

def initialize(paginator, number)
  @paginator = paginator
  @number = number.to_i
  @number = 1 unless @paginator.has_page_number? @number
end

Instance Attribute Details

#number ⇒ Object (readonly) Also known as: to_i

Returns the value of attribute number.



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# File 'app/helpers/pagination_helper.rb', line 375

def number
  @number
end

#paginator ⇒ Object (readonly)

Returns the value of attribute paginator.



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# File 'app/helpers/pagination_helper.rb', line 375

def paginator
  @paginator
end

Instance Method Details

#<=>(page) ⇒ Object

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.

Raises:

  • (ArgumentError) 


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# File 'app/helpers/pagination_helper.rb', line 390

def <=>(page)
  raise ArgumentError unless @paginator == page.paginator
  @number <=> page.number
end

#==(page) ⇒ Object

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).



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# File 'app/helpers/pagination_helper.rb', line 381

def ==(page)
  @paginator == page.paginator and 
    @number == page.number
end

#first? ⇒ Boolean

Returns true if this page is the first page in the paginator.

Returns:

  • (Boolean) 


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# File 'app/helpers/pagination_helper.rb', line 411

def first?
  self == @paginator.first
end

#first_item ⇒ Object

Returns the number of the first item displayed.



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# File 'app/helpers/pagination_helper.rb', line 401

def first_item
  offset + 1
end

#last? ⇒ Boolean

Returns true if this page is the last page in the paginator.

Returns:

  • (Boolean) 


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# File 'app/helpers/pagination_helper.rb', line 416

def last?
  self == @paginator.last
end

#last_item ⇒ Object

Returns the number of the last item displayed.



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# File 'app/helpers/pagination_helper.rb', line 406

def last_item
  [@paginator.items_per_page * @number, @paginator.item_count].min
end

#next ⇒ Object

Returns a new Page object representing the page just after this page, or nil if this is the last page.



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# File 'app/helpers/pagination_helper.rb', line 428

def next
  if last? then nil else Page.new(@paginator, @number + 1) end
end

#offset ⇒ Object

Returns the item offset for the first item in this page.



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# File 'app/helpers/pagination_helper.rb', line 396

def offset
  @paginator.items_per_page * (@number - 1)
end

#previous ⇒ Object

Returns a new Page object representing the page just before this page, or nil if this is the first page.



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# File 'app/helpers/pagination_helper.rb', line 422

def previous
  if first? then nil else Page.new(@paginator, @number - 1) end
end

#to_link(params = {}) ⇒ Object

Returns a hash appropriate for using with link_to or url_for. Takes an optional params hash for specifying additional link parameters.



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# File 'app/helpers/pagination_helper.rb', line 440

def to_link(params={})
  {:params => {@paginator.page_parameter => @number.to_s}.merge(params)}
end

#to_sql ⇒ Object

Returns the SQL “LIMIT … OFFSET” clause for this page.



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# File 'app/helpers/pagination_helper.rb', line 445

def to_sql
  ['? OFFSET ?', @paginator.items_per_page, offset]
end

#window(padding = 2) ⇒ Object

Returns a new Window object for this page with the specified padding.



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# File 'app/helpers/pagination_helper.rb', line 434

def window(padding=2)
  Window.new(self, padding)
end