Meta: page_count

README.md

@@ -1877,6 +1877,10 @@ JSONAPI.configure do |config|
   config.top_level_meta_include_record_count = false
   config.top_level_meta_record_count_key = :record_count
 
+  # For :paged paginators, the following are also available
+  config.top_level_meta_include_page_count = false
+  config.top_level_meta_page_count_key = :page_count
+
   config.use_text_errors = false
 
   # List of classes that should not be rescued by the operations processor.

lib/jsonapi/configuration.rb

@@ -20,6 +20,8 @@ class Configuration
                 :top_level_links_include_pagination,
                 :top_level_meta_include_record_count,
                 :top_level_meta_record_count_key,
+                :top_level_meta_include_page_count,
+                :top_level_meta_page_count_key,
                 :exception_class_whitelist,
                 :always_include_to_one_linkage_data,
                 :always_include_to_many_linkage_data,
@@ -59,6 +61,9 @@ def initialize
       self.top_level_meta_include_record_count = false
       self.top_level_meta_record_count_key = :record_count
 
+      self.top_level_meta_include_page_count = false
+      self.top_level_meta_page_count_key = :page_count
+
       self.use_text_errors = false
 
       # List of classes that should not be rescued by the operations processor.
@@ -164,6 +169,10 @@ def exception_class_whitelisted?(e)
 
     attr_writer :top_level_meta_record_count_key
 
+    attr_writer :top_level_meta_include_page_count
+
+    attr_writer :top_level_meta_page_count_key
+
     attr_writer :exception_class_whitelist
 
     attr_writer :always_include_to_one_linkage_data

lib/jsonapi/operation.rb

@@ -31,6 +31,12 @@ def record_count
                                                     include_directives: @include_directives)
     end
 
+    def page_count
+      if @paginator.is_a?(PagedPaginator)
+        @_page_count ||= @paginator.calculate_page_count(record_count)
+      end
+    end
+
     def pagination_params
       if @paginator && JSONAPI.configuration.top_level_links_include_pagination
         options = {}
@@ -57,6 +63,10 @@ def apply
         options[:record_count] = record_count
       end
 
+      if JSONAPI.configuration.top_level_meta_include_page_count
+        options[:page_count] = page_count
+      end
+
       return JSONAPI::ResourcesOperationResult.new(:ok,
                                                    resource_records,
                                                    options)
@@ -153,6 +163,12 @@ def record_count
       @_record_count ||= records.count(:all)
     end
 
+    def page_count
+      if @paginator.is_a?(PagedPaginator)
+        @_page_count ||= @paginator.calculate_page_count(record_count)
+      end
+    end
+
     def source_resource
       @_source_resource ||= @source_klass.find_by_key(@source_id, context: @context)
     end
@@ -176,6 +192,7 @@ def options
       opts = {}
       opts.merge!(pagination_params: pagination_params) if JSONAPI.configuration.top_level_links_include_pagination
       opts.merge!(record_count: record_count) if JSONAPI.configuration.top_level_meta_include_record_count
+      opts.merge!(page_count: page_count) if JSONAPI.configuration.top_level_meta_include_page_count
       opts
     end
 

lib/jsonapi/operation_result.rb

@@ -32,12 +32,13 @@ def initialize(code, resource, options = {})
   end
 
   class ResourcesOperationResult < OperationResult
-    attr_accessor :resources, :pagination_params, :record_count
+    attr_accessor :resources, :pagination_params, :record_count, :page_count
 
     def initialize(code, resources, options = {})
       @resources = resources
       @pagination_params = options.fetch(:pagination_params, {})
       @record_count = options[:record_count]
+      @page_count = options[:page_count]
       super(code, options)
     end
   end

lib/jsonapi/paginator.rb

@@ -131,14 +131,18 @@ def self.requires_record_count
     true
   end
 
+  def calculate_page_count(record_count)
+    (record_count / @size.to_f).ceil
+  end
+
   def apply(relation, _order_options)
     offset = (@number - 1) * @size
     relation.offset(offset).limit(@size)
   end
 
   def links_page_params(options = {})
     record_count = options[:record_count]
-    page_count = (record_count / @size.to_f).ceil
+    page_count = calculate_page_count(record_count)
 
     links_page_params = {}
 

lib/jsonapi/response_document.rb

@@ -54,6 +54,10 @@ def top_level_meta
         if JSONAPI.configuration.top_level_meta_include_record_count && result.respond_to?(:record_count)
           meta[JSONAPI.configuration.top_level_meta_record_count_key] = result.record_count
         end
+
+        if JSONAPI.configuration.top_level_meta_include_page_count && result.respond_to?(:page_count)
+          meta[JSONAPI.configuration.top_level_meta_page_count_key] = result.page_count
+        end
       end
 
       meta.deep_transform_keys { |key| @key_formatter.format(key) }

test/controllers/controller_test.rb

@@ -367,6 +367,15 @@ def test_show_does_not_include_records_count_in_meta
     JSONAPI.configuration.top_level_meta_include_record_count = false
   end
 
+  def test_show_does_not_include_pages_count_in_meta
+    JSONAPI.configuration.top_level_meta_include_page_count = true
+    get :show, { id: Post.first.id }
+    assert_response :success
+    assert_equal json_response['meta'], nil
+  ensure
+    JSONAPI.configuration.top_level_meta_include_page_count = false
+  end
+
   def test_show_single_with_includes
     get :show, params: {id: '1', include: 'comments'}
     assert_response :success
@@ -2678,6 +2687,18 @@ def test_books_record_count_in_meta
     assert_equal 'Book 0', json_response['data'][0]['attributes']['title']
   end
 
+  def test_books_page_count_in_meta
+    Api::V2::BookResource.paginator :paged
+    JSONAPI.configuration.top_level_meta_include_page_count = true
+    get :index, params: {include: 'book-comments'}
+    JSONAPI.configuration.top_level_meta_include_page_count = false
+
+    assert_response :success
+    assert_equal 91, json_response['meta']['page-count']
+    assert_equal 10, json_response['data'].size
+    assert_equal 'Book 0', json_response['data'][0]['attributes']['title']
+  end
+
   def test_books_record_count_in_meta_custom_name
     Api::V2::BookResource.paginator :offset
     JSONAPI.configuration.top_level_meta_include_record_count = true
@@ -2693,6 +2714,21 @@ def test_books_record_count_in_meta_custom_name
     assert_equal 'Book 0', json_response['data'][0]['attributes']['title']
   end
 
+  def test_books_page_count_in_meta_custom_name
+    Api::V2::BookResource.paginator :paged
+    JSONAPI.configuration.top_level_meta_include_page_count = true
+    JSONAPI.configuration.top_level_meta_page_count_key = 'total_pages'
+
+    get :index, params: {include: 'book-comments'}
+    JSONAPI.configuration.top_level_meta_include_page_count = false
+    JSONAPI.configuration.top_level_meta_page_count_key = :page_count
+
+    assert_response :success
+    assert_equal 91, json_response['meta']['total-pages']
+    assert_equal 10, json_response['data'].size
+    assert_equal 'Book 0', json_response['data'][0]['attributes']['title']
+  end
+
   def test_books_offset_pagination_no_params_includes_query_count_one_level
     Api::V2::BookResource.paginator :offset
 

test/integration/requests/request_test.rb

@@ -477,6 +477,22 @@ def test_filter_related_resources
     JSONAPI.configuration.top_level_meta_include_record_count = false
   end
 
+  def test_page_count_meta
+    Api::V2::BookCommentResource.paginator :paged
+    JSONAPI.configuration.top_level_meta_include_record_count = true
+    JSONAPI.configuration.top_level_meta_include_page_count = true
+    get '/api/v2/books/1/book_comments'
+    assert_equal 26, json_response['meta']['record_count']
+    # based on default page size
+    assert_equal 3, json_response['meta']['page_count']
+    get '/api/v2/books/1/book_comments?page[size]=5'
+    assert_equal 26, json_response['meta']['record_count']
+    assert_equal 6, json_response['meta']['page_count']
+  ensure
+    JSONAPI.configuration.top_level_meta_include_record_count = false
+    JSONAPI.configuration.top_level_meta_include_page_count = false
+  end
+
   def test_pagination_related_resources_without_related
     Api::V2::BookResource.paginator :offset
     Api::V2::BookCommentResource.paginator :offset