30 lines
1.1 KiB
Ruby
30 lines
1.1 KiB
Ruby
module PaginationMethods
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extend ActiveSupport::Concern
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private
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##
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# limit selected items to one page, get ids of first item before/after the page
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def get_page_items(items, includes: [], limit: 20)
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param! :before, Integer, :min => 1
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param! :after, Integer, :min => 1
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id_column = "#{items.table_name}.id"
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page_items = if params[:before]
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items.where("#{id_column} < ?", params[:before]).order(:id => :desc)
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elsif params[:after]
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items.where("#{id_column} > ?", params[:after]).order(:id => :asc)
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else
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items.order(:id => :desc)
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end
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page_items = page_items.limit(limit)
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page_items = page_items.includes(includes)
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page_items = page_items.sort.reverse
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newer_items_id = page_items.first.id if page_items.count.positive? && items.exists?(["#{id_column} > ?", page_items.first.id])
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older_items_id = page_items.last.id if page_items.count.positive? && items.exists?(["#{id_column} < ?", page_items.last.id])
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[page_items, newer_items_id, older_items_id]
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end
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end
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