Module: Foliate::Controller

Defined in:
lib/foliate/controller.rb

Instance Method Summary collapse

Instance Method Details

#paginate(records, per_page: nil, total_records: nil) ⇒ ActiveRecord::Relation, Array

Paginates records, and returns the current page of records according to params[Foliate.config.page_param] (typically, params[:page]). Also sets the @pagination instance variable for use in the view (see Pagination).

Returns an ActiveRecord::Relation if records is an ActiveRecord::Relation. Returns an Array if records is an Array.

By default, allots Foliate.config.default_per_page number of records per page. This can be overridden by specifying per_page:.

By default, if records is an ActiveRecord::Relation, computes the total number of pages by performing a SQL count query. If the underlying table is very large, this query can have a noticeable performance cost. This can be circumvented by specifying total_records:, using an estimated or cached record count.

Examples:

basic pagination

@posts = paginate(Post)

paginated search

@posts = paginate(Post.where(author: params[:author]))

user-specified per_page

@posts = paginate(Post, per_page: params[:per])

simple cached count

count = Rails.cache.fetch("Post/count", expires_in: 5.minutes){ Post.count }
@posts = paginate(Post, total_records: count)

Parameters:

  • records (ActiveRecord::Relation, Array)
  • per_page (Integer, String) (defaults to: nil)
  • total_records (Integer) (defaults to: nil)

Returns:

  • (ActiveRecord::Relation, Array) 


44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
 
# File 'lib/foliate/controller.rb', line 44

def paginate(records, per_page: nil, total_records: nil)
  @pagination = Foliate::Pagination.new.tap do |p|
    p.current_page = [params[Foliate.config.page_param].to_i, 1].max
    p.per_page = per_page.try(&:to_i) || Foliate.config.default_per_page
    p.total_records = total_records || (records.is_a?(Array) ?
      records.length : records.unscope(:limit).unscope(:offset).count)
    p.controller = params[:controller]
    p.action = params[:action]
    p.query_params = request.query_parameters.except(Foliate.config.page_param)
  end

  records.is_a?(Array) ?
    records[@pagination.offset, @pagination.per_page].to_a :
    records.limit(@pagination.per_page).offset(@pagination.offset)
end