Module: ActiveRpc::Rpc::Concerns::Paginatable

Extended by:
ActiveSupport::Concern
Included in:
QueryBuilder
Defined in:
lib/active_rpc/rpc/concerns/paginatable.rb

Overview

The Paginatable concern provides methods for applying pagination to ActiveRecord queries in gRPC controllers.

It supports:

  • Standard pagination with page and per_page parameters

  • Integration with the Pagy gem if available

  • Pagination metadata for responses

Examples:

def list_users
  process_request do
    base_query = User.all
    query = apply_pagination(base_query, request.message)
    # ...
  end
end

Instance Method Summary collapse

Instance Method Details

#apply_pagination(query, params) ⇒ Object

Apply pagination to a query only if explicitly requested



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# File 'lib/active_rpc/rpc/concerns/paginatable.rb', line 28

def apply_pagination(query, params)
  return query unless pagination_params?(params)

  begin
    page, per_page = sanitized_page_params(params)
    base_options = defined?(Pagy::OPTIONS) ? Pagy::OPTIONS : Pagy::DEFAULT
    options = base_options.merge(rpc_pagy_options(page, per_page))
    pagy, records = Pagy::OffsetPaginator.paginate(query, options)
    @last_pagy = pagy
    records
  rescue StandardError => e
    Rails.logger.error("Error applying pagination: #{e.message}")
    # Return original query if pagination fails
    query
  end
end

#pagination_metadata(query, params, total_count = nil) ⇒ Object

Get pagination metadata



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# File 'lib/active_rpc/rpc/concerns/paginatable.rb', line 46

def pagination_metadata(query, params, total_count = nil)
  # If Pagy was used, get metadata from it
  if defined?(@last_pagy) && @last_pagy
    return {
      total_count: @last_pagy.count,
      page: @last_pagy.page,
      per_page: @last_pagy.limit,
      total_pages: @last_pagy.last
    }
  end

  # If pagination is not requested, return metadata with all records
  unless params.respond_to?(:page) && params.respond_to?(:per_page) &&
         params.page.present? && params.per_page.present?
    total_count = query.count
    return {
      total_count: total_count,
      page: 1,
      per_page: total_count,
      total_pages: 1
    }
  end

  # Calculate total count and pages
  total_count ||= query.except(:limit, :offset).count

  # Validate and sanitize per_page parameter
  per_page = params.per_page.to_i
  if per_page <= 0
    Rails.logger.warn("Invalid per_page value: #{params.per_page}. Using default value.")
    per_page = ActiveRpc::Rpc.configuration.default_per_page || 20
  end

  # Ensure per_page doesn't exceed maximum allowed
  max_per_page = ActiveRpc::Rpc.configuration.max_per_page || 100
  per_page = [ per_page, max_per_page ].min

  # Calculate total pages safely
  total_pages = total_count > 0 ? (total_count.to_f / per_page).ceil : 1

  {
    total_count: total_count,
    page: params.page,
    per_page: per_page,
    total_pages: total_pages
  }
end