Module: Dscf::Core::Pagination

Extended by:
ActiveSupport::Concern
Included in:
Common
Defined in:
app/controllers/concerns/dscf/core/pagination.rb

Instance Method Summary collapse

Instance Method Details

#default_per_page ⇒ Object 



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 6

def default_per_page
  10
end

#order_by ⇒ Object 



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 22

def order_by
  allowed_columns = if respond_to?(:allowed_order_columns, true)
                      allowed_order_columns
                    else
                      %w[id created_at updated_at]
                    end
  requested_column = params.fetch(:order_by, "id").to_s
  allowed_columns.include?(requested_column) ? requested_column : "id"
end

#order_direction ⇒ Object 



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 32

def order_direction
  if %w[asc desc].include?(params.fetch(:order_direction, "asc").to_s.downcase)
    params.fetch(:order_direction, "asc").to_s.downcase
  else
    "asc"
  end
end

#page_no ⇒ Object 



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 10

def page_no
  params[:page]&.to_i || 1
end

#paginate ⇒ Object 



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 40

def paginate
  ->(it) { it.limit(per_page).offset(paginate_offset).order("#{order_by}": order_direction) }
end

#paginate_offset ⇒ Object 



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 18

def paginate_offset
  (page_no - 1) * per_page
end

#pagination_links(total_pages) ⇒ Object

Generate HATEOAS pagination links



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 45

def pagination_links(total_pages)
  base_path = request.path
  current_params = request.query_parameters.except("page")

  links = {}

  links[:first] = build_page_url(base_path, current_params, 1)

  links[:prev] = (build_page_url(base_path, current_params, page_no - 1) if page_no > 1)

  links[:next] = (build_page_url(base_path, current_params, page_no + 1) if page_no < total_pages)

  links[:last] = build_page_url(base_path, current_params, total_pages)

  links
end

#per_page ⇒ Object 



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# File 'app/controllers/concerns/dscf/core/pagination.rb', line 14

def per_page
  params[:per_page]&.to_i || default_per_page
end