Module: SmritiPaginate

Extended by:
ActiveSupport::Concern
Included in:
Smriti::ApplicationRecord
Defined in:
app/models/concerns/smriti_paginate.rb

Overview

Note:

Methods are added as class methods to the including model.

SmritiPaginate

Concern that adds a class-level paginate scope to models, enabling simple pagination based on page and per_page parameters.

Usage

Smriti::MatViewDefinition.paginate(total: 100, page: 2, per_page: 20)
# => Returns records 21-40 of the total 100

Class Method Summary collapse

Class Method Details

.paginate(total:, page:, per_page:) ⇒ ActiveRecord::Relation

Paginates the relation based on total records, current page, and per-page count.

Parameters:

  • total (Integer) —

    Total number of records in the full result set.

  • page (Integer) —

    Current page number (1-based).

  • per_page (Integer) —

    Number of records per page.

Returns:

  • (ActiveRecord::Relation) —

    Paginated relation.



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# File 'app/models/concerns/smriti_paginate.rb', line 28

module SmritiPaginate
  extend ActiveSupport::Concern

  included do
    # Adds a scope for paginating records.
    # Usage: Model.paginate(total: total_count, page: current_page, per_page: per_page_count)
    #
    # Calculates the correct offset and limit based on the provided parameters.
    # Ensures page and per_page are within valid ranges.
    # Defaults per_page to 20 if an invalid value is provided.
    # Returns an ActiveRecord::Relation with the appropriate records.
    #
    # @param total [Integer] Total number of records in the full result set.
    # @param page [Integer] Current page number (1-based).
    # @param per_page [Integer] Number of records per page.
    #
    # @return [ActiveRecord::Relation] Paginated relation.
    scope :paginate, lambda { |total:, page:, per_page:|
      page = page.to_i
      per_page  = per_page.to_i
      per_page  = 20 if per_page <= 0

      total_pages = (total.to_f / per_page).ceil
      page = 1 if page < 1 || (page > total_pages && total_pages.positive?)

      offset((page - 1) * per_page).limit(per_page)
    }
  end
  class_methods do
    # Calculates the total number of pages based on total records and per-page count.
    #
    # @param total [Integer] Total number of records.
    # @param per_page [Integer] Number of records per page.
    # @return [Integer] Total number of pages.
    #
    # @example
    #   total_pages(total: 100, per_page: 20) #=> 5
    def total_pages(total:, per_page:)
      per_page = per_page.to_i
      (total.to_f / per_page).ceil
    end
  end
end