69 lines
2.2 KiB
Ruby
69 lines
2.2 KiB
Ruby
module API
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module Helpers
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module Pagination
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def paginate(relation)
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relation = add_default_order(relation)
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relation.page(params[:page]).per(params[:per_page]).tap do |data|
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add_pagination_headers(data)
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end
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end
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private
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def add_pagination_headers(paginated_data)
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header 'X-Per-Page', paginated_data.limit_value.to_s
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header 'X-Page', paginated_data.current_page.to_s
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header 'X-Next-Page', paginated_data.next_page.to_s
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header 'X-Prev-Page', paginated_data.prev_page.to_s
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header 'Link', pagination_links(paginated_data)
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return if data_without_counts?(paginated_data)
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header 'X-Total', paginated_data.total_count.to_s
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header 'X-Total-Pages', total_pages(paginated_data).to_s
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end
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def pagination_links(paginated_data)
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request_url = request.url.split('?').first
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request_params = params.clone
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request_params[:per_page] = paginated_data.limit_value
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links = []
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request_params[:page] = paginated_data.prev_page
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links << %(<#{request_url}?#{request_params.to_query}>; rel="prev") if request_params[:page]
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request_params[:page] = paginated_data.next_page
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links << %(<#{request_url}?#{request_params.to_query}>; rel="next") if request_params[:page]
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request_params[:page] = 1
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links << %(<#{request_url}?#{request_params.to_query}>; rel="first")
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unless data_without_counts?(paginated_data)
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request_params[:page] = total_pages(paginated_data)
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links << %(<#{request_url}?#{request_params.to_query}>; rel="last")
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end
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links.join(', ')
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end
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def total_pages(paginated_data)
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# Ensure there is in total at least 1 page
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[paginated_data.total_pages, 1].max
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end
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def add_default_order(relation)
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if relation.is_a?(ActiveRecord::Relation) && relation.order_values.empty?
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relation = relation.order(:id)
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end
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relation
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end
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def data_without_counts?(paginated_data)
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paginated_data.is_a?(Kaminari::PaginatableWithoutCount)
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end
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end
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end
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end
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