Class: Pagify::BasicPager

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/pagify/pager/basic.rb

Overview

pager is something help you paginate the data, through the fetcher and counter you pass in. e.g., for a array, the fetcher would be array[offset, per_page], the counter would be array.size. and for data mapper’s resource, fetcher would be Model.all :offset => offset, :limit => per_page. see ArrayPager and DataMapperPager, ActiveRecordPager, etc. if you just simply need them or have a look at the source code for example usage for Pager.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ BasicPager

fetcher is function that fetch the data,

counter is function that count the data,
null_page indicates that pager sohuld

the default per_page is 20. you can reset per_page property later.

Raises:

  • (ArgumentError) 


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# File 'lib/pagify/pager/basic.rb', line 30

def initialize opts = {}
  raise ArgumentError.new('missing fetcher and/or counter.') if
    !opts[:fetcher] || !opts[:counter]

  raise ArgumentError.new('fetcher or counter does not respond to call.') if
    !opts[:fetcher].respond_to?(:call) || !opts[:counter].respond_to?(:call)

  @opts     = {}
  @fetcher  = opts[:fetcher]
  @counter  = opts[:counter]

  self.per_page  = opts[:per_page]  || 20
  self.null_page = opts[:null_page] || true
end

Instance Attribute Details

#counter ⇒ Object (readonly)

Returns the value of attribute counter.



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# File 'lib/pagify/pager/basic.rb', line 13

def counter
  @counter
end

#fetcher ⇒ Object (readonly)

Returns the value of attribute fetcher.



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# File 'lib/pagify/pager/basic.rb', line 13

def fetcher
  @fetcher
end

#opts ⇒ Object

Returns the value of attribute opts.



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# File 'lib/pagify/pager/basic.rb', line 14

def opts
  @opts
end

Instance Method Details

#==(rhs) ⇒ Object

if two paginators are equal, then the properties of per_page, fetcher, counter are all equal.



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# File 'lib/pagify/pager/basic.rb', line 47

def == rhs
  return false unless rhs
  self.per_page == rhs.per_page and
  self.fetcher  == rhs.fetcher  and
  self.counter  == rhs.counter
end

#each ⇒ Object

for each page…



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# File 'lib/pagify/pager/basic.rb', line 55

def each; 1.upto(size){ |i| yield page(i) }; end

#entries_count ⇒ Object

simply call @counter.call



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# File 'lib/pagify/pager/basic.rb', line 90

def entries_count; counter.call; end

#offset(page) ⇒ Object

get the offset property about the page. it is simply (page-1)*@per_page



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# File 'lib/pagify/pager/basic.rb', line 94

def offset page
  (normalize_page(page) - 1) * per_page
end

#page(page) ⇒ Object Also known as: []

create page instance by page number. if page number you specified was not existed, nil would be returned. note, page start at 1, not zero.



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# File 'lib/pagify/pager/basic.rb', line 70

def page page
  if page_exists?(page)
    return BasicPage.new(self, normalize_page(page))

  else
    if null_page
      return null_page_instance
    else
      return nil
    end

  end

end

#page_exists?(page) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pagify/pager/basic.rb', line 61

def page_exists? page
  page = normalize_page(page)
  offset = (page - 1) * per_page
  page > 0 && offset < entries_count
end

#size ⇒ Object

return the amount of pages



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# File 'lib/pagify/pager/basic.rb', line 87

def size; (entries_count / per_page.to_f).ceil; end

#to_a ⇒ Object Also known as: pages

return all pages in an array



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# File 'lib/pagify/pager/basic.rb', line 58

def to_a; map{ |e| e }; end