Class: Bridgetown::Paginate::Generator::PaginationGenerator

Inherits:
Generator
  • Object
show all
Defined in:
lib/bridgetown-paginate/pagination_generator.rb

Overview

The main entry point into the generator, called by Bridgetown this function extracts all the necessary information from the Bridgetown end and passes it into the pagination logic. Additionally it also contains all site specific actions that the pagination logic needs access to (such as how to create new pages)

Instance Method Summary collapse

Instance Method Details

#generate(site) ⇒ Object

Generate paginated pages if necessary (Default entry point) site - The Site.

Returns nothing.



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# File 'lib/bridgetown-paginate/pagination_generator.rb', line 21

def generate(site)
  # Retrieve and merge the pagination configuration from the site yml file
  default_config = Bridgetown::Utils.deep_merge_hashes(
    DEFAULT,
    site.config["pagination"] || {}
  )

  # If disabled then simply quit
  unless default_config["enabled"]
    Bridgetown.logger.info "Pagination:", "disabled. Enable in site config" \
      " with pagination:\\n  enabled: true"
    return
  end

  Bridgetown.logger.debug "Pagination:", "Starting"

  ################ 0 ####################
  # Get all pages in the site (this will be used to find the pagination
  # templates)
  all_pages = site.pages

  # Get the default title of the site (used as backup when there is no
  # title available for pagination)
  site_title = site.data.dig("metadata", "title") || site.config["title"]

  ################ 1 ####################
  # Specify the callback function that returns the correct docs/posts
  # based on the collection name
  # "posts" are just another collection in Bridgetown but a specialized
  # version that require timestamps
  # This collection is the default and if the user doesn't specify a
  # collection in their front-matter then that is the one we load
  # If the collection is not found then empty array is returned
  collection_by_name_lambda = lambda do |collection_name|
    coll = []
    if collection_name == "all"
      # the 'all' collection_name is a special case and includes all
      # collections in the site (except posts!!)
      # this is useful when you want to list items across multiple collections
      site.collections.each do |coll_name, coll_data|
        next unless !coll_data.nil? && coll_name != "posts"

        # Exclude all pagination pages
        coll += coll_data.docs.reject do |doc|
          doc.data.key?("pagination")
        end
      end
    else
      # Just the one collection requested
      return [] unless site.collections.key?(collection_name)

      # Exclude all pagination pages
      coll = site.collections[collection_name].docs.reject do |doc|
        doc.data.key?("pagination")
      end
    end
    return coll
  end

  ################ 2 ####################
  # Create the proc that constructs the real-life site page
  # This is necessary to decouple the code from the Bridgetown site object
  page_add_lambda = lambda do |newpage|
    site.pages << newpage # Add the page to the site so that it is generated correctly
    return newpage # Return the site to the calling code
  end

  ################ 2.5 ####################
  # lambda that removes a page from the site pages list
  page_remove_lambda = lambda do |page_to_remove|
    site.pages.delete_if { |page| page == page_to_remove }
  end

  ################ 3 ####################
  # Create a proc that will delegate logging
  # Decoupling Bridgetown specific logging
  logging_lambda = lambda do |message, type = "info"|
    if type == "debug"
      Bridgetown.logger.debug "Pagination:", message.to_s
    elsif type == "error"
      Bridgetown.logger.error "Pagination:", message.to_s
    elsif type == "warn"
      Bridgetown.logger.warn "Pagination:", message.to_s
    else
      Bridgetown.logger.info "Pagination:", message.to_s
    end
  end

  ################ 4 ####################
  # Now create and call the model with the real-life page creation proc and site data
  model = PaginationModel.new(
    logging_lambda,
    page_add_lambda,
    page_remove_lambda,
    collection_by_name_lambda
  )
  count = model.run(default_config, all_pages, site_title)
  Bridgetown.logger.info "Pagination:", "Complete, processed #{count} pagination page(s)"
end