Introduce InertiaRails.scroll

Author: skryukov

Gemfile

@@ -17,3 +17,6 @@ gem 'responders'
 gem 'rspec-rails', '~> 6.0'
 gem 'rubocop', '~> 1.21'
 gem 'sqlite3'
+
+gem 'kaminari'
+gem 'pagy'

lib/inertia_rails/defer_prop.rb

@@ -2,27 +2,16 @@
 
 module InertiaRails
   class DeferProp < IgnoreOnFirstLoadProp
-    DEFAULT_GROUP = 'default'
+    prepend PropMergeable
 
-    attr_reader :group, :match_on
+    DEFAULT_GROUP = 'default'
 
-    def initialize(group: nil, merge: nil, deep_merge: nil, match_on: nil, &block)
-      raise ArgumentError, 'Cannot set both `deep_merge` and `merge` to true' if deep_merge && merge
+    attr_reader :group
 
+    def initialize(**props, &block)
       super(&block)
 
-      @group = group || DEFAULT_GROUP
-      @merge = merge || deep_merge
-      @deep_merge = deep_merge
-      @match_on = match_on.nil? ? nil : Array(match_on)
-    end
-
-    def merge?
-      @merge
-    end
-
-    def deep_merge?
-      @deep_merge
+      @group = props[:group] || DEFAULT_GROUP
     end
   end
 end

lib/inertia_rails/inertia_rails.rb

@@ -1,12 +1,14 @@
 # frozen_string_literal: true
 
+require 'inertia_rails/prop_mergeable'
 require 'inertia_rails/base_prop'
 require 'inertia_rails/ignore_on_first_load_prop'
 require 'inertia_rails/always_prop'
 require 'inertia_rails/lazy_prop'
 require 'inertia_rails/optional_prop'
 require 'inertia_rails/defer_prop'
 require 'inertia_rails/merge_prop'
+require 'inertia_rails/scroll_prop'
 require 'inertia_rails/configuration'
 require 'inertia_rails/meta_tag'
 
@@ -34,8 +36,8 @@ def always(&block)
       AlwaysProp.new(&block)
     end
 
-    def merge(match_on: nil, &block)
-      MergeProp.new(match_on: match_on, &block)
+    def merge(...)
+      MergeProp.new(...)
     end
 
     def deep_merge(match_on: nil, &block)
@@ -45,5 +47,9 @@ def deep_merge(match_on: nil, &block)
     def defer(group: nil, merge: nil, deep_merge: nil, match_on: nil, &block)
       DeferProp.new(group: group, merge: merge, deep_merge: deep_merge, match_on: match_on, &block)
     end
+
+    def scroll(metadata = nil, **options, &block)
+      ScrollProp.new(metadata: metadata, **options, &block)
+    end
   end
 end

lib/inertia_rails/merge_prop.rb

@@ -2,20 +2,11 @@
 
 module InertiaRails
   class MergeProp < BaseProp
-    attr_reader :match_on
+    prepend PropMergeable
 
-    def initialize(deep_merge: false, match_on: nil, &block)
+    def initialize(**_props, &block)
       super(&block)
-      @deep_merge = deep_merge
-      @match_on = match_on.nil? ? nil : Array(match_on)
-    end
-
-    def merge?
-      true
-    end
-
-    def deep_merge?
-      @deep_merge
+      @merge = true
     end
   end
 end

lib/inertia_rails/prop_mergeable.rb

@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+module InertiaRails
+  module PropMergeable
+    attr_reader :match_on, :appends_at_paths, :prepends_at_paths
+
+    def initialize(**props, &block)
+      raise ArgumentError, 'Cannot set both `deep_merge` and `merge` to true' if props[:deep_merge] && props[:merge]
+
+      @deep_merge = props.fetch(:deep_merge, false)
+      @merge = props[:merge] || @deep_merge
+      @match_on = props[:match_on].nil? ? nil : Array(props[:match_on])
+      @appends_at_paths = []
+      @prepends_at_paths = []
+      @append = true
+
+      append(props[:append]) if props.key?(:append)
+      prepend(props[:prepend]) if props.key?(:prepend)
+
+      super
+    end
+
+    def appends_at_root?
+      @append && merges_at_root?
+    end
+
+    def prepends_at_root?
+      !@append && merges_at_root?
+    end
+
+    def merges_at_root?
+      merge? && appends_at_paths.none? && prepends_at_paths.none?
+    end
+
+    def merge?
+      @merge
+    end
+
+    def deep_merge?
+      @deep_merge
+    end
+
+    private
+
+    def append(path, match_on: nil)
+      case path
+      when TrueClass, FalseClass
+        @append = path
+      when String
+        @appends_at_paths << path
+      when Array
+        @appends_at_paths += path
+      when Hash
+        @match_on ||= []
+        path.each do |key, value|
+          @appends_at_paths << key.to_s
+          @match_on << "#{key}.#{value}" if value
+        end
+      end
+
+      (@match_on ||= []) << "#{path}.#{match_on}" if match_on && path.is_a?(String)
+    end
+
+    def prepend(path, match_on: nil)
+      case path
+      when TrueClass, FalseClass
+        @append = !path
+      when String
+        @prepends_at_paths << path
+      when Array
+        @prepends_at_paths += path
+      when Hash
+        @match_on ||= []
+        path.each do |key, value|
+          @prepends_at_paths << key.to_s
+          @match_on << "#{key}.#{value}" if value
+        end
+      end
+
+      (@match_on ||= []) << "#{path}.#{match_on}" if match_on && path.is_a?(String)
+    end
+  end
+end

lib/inertia_rails/renderer.rb

@@ -104,12 +104,13 @@ def computed_props
         .tap do |props| # Add meta tags last (never transformed)
         props[:_inertia_meta] = meta_tags if meta_tags.present?
       end
-
       # rubocop:enable Style/MultilineBlockChain
     end
 
     def page
-      default_page = {
+      return @page if defined?(@page)
+
+      @page = {
         component: component,
         props: computed_props,
         url: @request.original_fullpath,
@@ -119,21 +120,11 @@ def page
       }
 
       deferred_props = deferred_props_keys
-      default_page[:deferredProps] = deferred_props if deferred_props.present?
-
-      deep_merge_props, merge_props = all_merge_props.partition do |_key, prop|
-        prop.deep_merge?
-      end
+      @page[:deferredProps] = deferred_props if deferred_props.present?
+      @page[:scrollProps] = scroll_props if scroll_props.present?
+      @page.merge!(resolve_merge_props)
 
-      match_props_on = all_merge_props.filter_map do |key, prop|
-        prop.match_on.map { |ms| "#{key}.#{ms}" } if prop.match_on.present?
-      end.flatten
-
-      default_page[:mergeProps] = merge_props.map(&:first) if merge_props.present?
-      default_page[:deepMergeProps] = deep_merge_props.map(&:first) if deep_merge_props.present?
-      default_page[:matchPropsOn] = match_props_on if match_props_on.present?
-
-      default_page
+      @page
     end
 
     def deep_transform_props(props, parent_path = [])
@@ -165,10 +156,28 @@ def deferred_props_keys
       end
     end
 
-    def all_merge_props
-      @all_merge_props ||= @props.select do |key, prop|
+    def resolve_merge_props
+      deep_merge_props, merge_props = all_merge_props.partition do |_key, prop|
+        prop.deep_merge?
+      end
+
+      {
+        mergeProps: append_merge_props(merge_props),
+        prependProps: prepend_merge_props(merge_props),
+        deepMergeProps: deep_merge_props.map!(&:first),
+        matchPropsOn: resolve_match_on_props,
+      }.delete_if { |_, v| v.blank? }
+    end
+
+    def resolve_match_on_props
+      all_merge_props.filter_map do |key, prop|
+        prop.match_on.map! { |ms| "#{key}.#{ms}" } if prop.match_on.present?
+      end.flatten
+    end
+
+    def requested_merge_props
+      @requested_merge_props ||= @props.select do |key, prop|
         next unless prop.try(:merge?)
-        next if reset_keys.include?(key)
         next if rendering_partial_component? && (
           (partial_keys.present? && partial_keys.exclude?(key.name)) ||
             (partial_except_keys.present? && partial_except_keys.include?(key.name))
@@ -178,16 +187,64 @@ def all_merge_props
       end
     end
 
+    def append_merge_props(props)
+      return props if props.empty?
+
+      root_append_props, nested_append_props = props.partition { |_key, prop| prop.appends_at_root? }
+
+      result = Set.new(root_append_props.map!(&:first))
+
+      nested_append_props.each do |key, prop|
+        prop.appends_at_paths.each do |path|
+          result.add("#{key}.#{path}")
+        end
+      end
+
+      result.to_a
+    end
+
+    def prepend_merge_props(props)
+      return props if props.empty?
+
+      root_prepend_props, nested_prepend_props = props.partition { |_key, prop| prop.prepends_at_root? }
+
+      result = Set.new(root_prepend_props.map!(&:first))
+
+      nested_prepend_props.each do |key, prop|
+        prop.prepends_at_paths.each do |path|
+          result.add("#{key}.#{path}")
+        end
+      end
+
+      result.to_a
+    end
+
+    def scroll_props
+      return @scroll_props if defined?(@scroll_props)
+
+      @scroll_props = {}
+      requested_merge_props.each do |key, prop|
+        next unless prop.is_a?(ScrollProp)
+
+        @scroll_props[key] = prop.metadata.merge!(reset: reset_keys.include?(key))
+      end
+      @scroll_props
+    end
+
+    def all_merge_props
+      @all_merge_props ||= requested_merge_props.reject { |key,| reset_keys.include?(key) }
+    end
+
     def partial_keys
-      @partial_keys ||= (@request.headers['X-Inertia-Partial-Data'] || '').split(',').compact
+      @partial_keys ||= (@request.headers['X-Inertia-Partial-Data'] || '').split(',').compact_blank!
     end
 
     def reset_keys
-      (@request.headers['X-Inertia-Reset'] || '').split(',').compact.map(&:to_sym)
+      @reset_keys ||= (@request.headers['X-Inertia-Reset'] || '').split(',').compact_blank!.map!(&:to_sym)
     end
 
     def partial_except_keys
-      (@request.headers['X-Inertia-Partial-Except'] || '').split(',').compact
+      @partial_except_keys ||= (@request.headers['X-Inertia-Partial-Except'] || '').split(',').compact_blank!
     end
 
     def rendering_partial_component?