Preserve parsed styles in the instance

Author: blocknotes

examples/instance.pdf

@@ -15,15 +15,17 @@ def initialize(renderer, ignore_content_tags: %i[script style])
       @ignore = false
       @ignore_content_tags = ignore_content_tags
       @renderer = renderer
-      @styles = {}
+      @raw_styles = {}
     end
 
     # Processes HTML and renders it
     #
     # @param html [String] The HTML content to process
     def process(html)
+      @styles = {}
       @processing = !html.include?('<body')
       @document = Oga.parse_html(html)
+      process_styles # apply previously loaded styles
       traverse_nodes(document.children)
       renderer.flush
     end
@@ -59,9 +61,9 @@ def init_element(node)
       end
     end
 
-    def process_styles(text_styles)
-      hash_styles = text_styles.scan(REGEXP_STYLES).to_h
-      hash_styles.each do |selector, rule|
+    def process_styles(text_styles = nil)
+      @raw_styles = text_styles.scan(REGEXP_STYLES).to_h if text_styles
+      @raw_styles.each do |selector, rule|
         document.css(selector).each do |node|
           styles[node] = rule
         end

lib/prawn_html/html_parser.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+RSpec.describe 'Instance' do
+  it 'preserves the styles in the instance' do
+    pdf = Prawn::Document.new(page_size: 'A4')
+    phtml = PrawnHtml::Instance.new(pdf)
+    phtml.append(html: '<style>h1 { color: green }</style>')
+    phtml.append(html: '<h1>Some HTML before</h1>')
+    pdf.text 'Some Prawn text'
+    phtml.append(html: '<h1>Some HTML after</h1>')
+
+    output_file = File.expand_path('../../examples/instance.pdf', __dir__)
+    pdf.render_file(output_file) unless File.exist?(output_file)
+
+    expected_pdf = File.read(output_file)
+    expect(Zlib.crc32(pdf.render)).to eq Zlib.crc32(expected_pdf)
+  end
+end