39 lines
1.2 KiB
Ruby
39 lines
1.2 KiB
Ruby
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# frozen_string_literal: true
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module CursorPaginatable
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extend ActiveSupport::Concern
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module ClassMethods
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# Defines a cursor paginator.
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#
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# This method will define a new method +name+, which accepts the keyword
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# arguments +last_id+ for defining the last id the cursor will operate on,
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# and +size+ for the amount of records it should return.
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#
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# @param name [Symbol] The name of the method for the cursor paginator
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# @param scope [Symbol] The name of the method which returns an
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# ActiveRecord scope.
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#
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# @example
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# class User
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# has_many :answers
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#
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# include CursorPaginatable
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# define_cursor_paginator :cursored_answers, :recent_answers
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#
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# def recent_answers
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# self.answers.order(:created_at).reverse_order
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# end
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# end
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def define_cursor_paginator(name, scope, default_size: APP_CONFIG.fetch('items_per_page'))
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class_eval <<-RUBY, __FILE__, __LINE__ + 1
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def #{name}(*args, last_id: nil, size: #{default_size}, **kwargs)
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s = self.#{scope}(*args, **kwargs).limit(size)
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s = s.where(s.arel_table[:id].lt(last_id)) if last_id.present?
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s
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end
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RUBY
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end
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end
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end
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