Switch to Markly for HTML rendering

Unfortunately Markly does not include header generation, so for now I've
implemented this with a custom renderer.

CHANGELOG.md

@@ -1,4 +1,6 @@
 ## [Unreleased]
+- Replace Kramdown with Markly
+- Enabled support for Github Flavored Markdown tables and tasklists
 
 ## [0.5.4] - 2023-08-02
 - Fix page getting clobbered when wikilinks point to non-existent pages.

Gemfile.lock

@@ -2,8 +2,6 @@ PATH
   remote: .
   specs:
     obsidian-parser (0.5.4)
-      kramdown (~> 2.4)
-      kramdown-parser-gfm (~> 1.1)
       markly (~> 0.7.0)
 
 GEM
@@ -13,10 +11,6 @@ GEM
     coderay (1.1.3)
     diff-lcs (1.5.0)
     json (2.6.3)
-    kramdown (2.4.0)
-      rexml
-    kramdown-parser-gfm (1.1.0)
-      kramdown (~> 2.0)
     language_server-protocol (3.17.0.3)
     lint_roller (1.1.0)
     markly (0.7.0)

lib/obsidian/parser.rb

@@ -5,6 +5,7 @@
 require_relative "parser/obsidian_flavored_markdown"
 require_relative "parser/page"
 require_relative "parser/markdown_content"
+require_relative "parser/html_renderer"
 
 require "forwardable"
 
@@ -20,6 +21,7 @@ class Parser
 
     def initialize(vault_directory)
       @index = Obsidian::Page.create_root
+      renderer = HtmlRenderer.new
 
       vault_directory.glob("**/*.md").each do |path|
         dirname, basename = path.relative_path_from(vault_directory).split
@@ -39,7 +41,7 @@ def initialize(vault_directory)
         @index.add_page(
           slug,
           last_modified: path.mtime,
-          content: MarkdownContent.new(path, @index)
+          content: MarkdownContent.new(path, @index, renderer: renderer)
         )
       end
 

lib/obsidian/parser/html_renderer.rb

@@ -0,0 +1,40 @@
+class HtmlRenderer < Markly::Renderer::HTML
+  def header(node)
+    block do
+      out("<h", node.header_level, " id=\"", header_id(node), "\">",
+        :children, "</h", node.header_level, ">")
+    end
+  end
+
+  private
+
+  def header_id(node)
+    # Taken from Kramdown
+    # https://github.com/gettalong/kramdown/blob/bd678ecb59f70778fdb3b08bdcd39e2ab7379b45/lib/kramdown/converter/base.rb
+    gen_id = extract_text(node).gsub(/^[^a-zA-Z]+/, "")
+    gen_id.tr!("^a-zA-Z0-9 -", "")
+    gen_id.tr!(" ", "-")
+    gen_id.downcase!
+
+    gen_id = "section" if gen_id.empty?
+
+    @used_ids ||= {}
+    if @used_ids.key?(gen_id)
+      gen_id += "-#{@used_ids[gen_id] += 1}"
+    else
+      @used_ids[gen_id] = 0
+    end
+
+    gen_id
+  end
+
+  def extract_text(node)
+    node.each do |subnode|
+      if subnode.type == :text
+        return subnode.string_content
+      end
+    end
+
+    ""
+  end
+end

lib/obsidian/parser/markdown_content.rb

@@ -2,14 +2,15 @@
 
 module Obsidian
   class MarkdownContent
-    def initialize(path, root)
+    def initialize(path, root, renderer:)
       @path = path
       @root = root
+      @renderer = renderer
     end
 
     def generate_html
       markdown = @path.read
-      Obsidian::ObsidianFlavoredMarkdown.parse(markdown, root: @root).to_html
+      Obsidian::ObsidianFlavoredMarkdown.parse(markdown, root: @root, renderer: @renderer).to_html
     end
   end
 end

lib/obsidian/parser/obsidian_flavored_markdown.rb

@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require "kramdown"
-require "kramdown-parser-gfm"
 require "markly"
 
 module Obsidian
@@ -38,11 +36,10 @@ def self.expand_wikilinks(markdown_text, root:)
       end
     end
 
-    def self.parse(markdown_text, root: nil)
+    def self.parse(markdown_text, renderer:, root: nil)
       normalized = expand_wikilinks(markdown_text, root: root)
-      document = Kramdown::Document.new(normalized, input: "GFM")
-      document2 = Markly.parse(normalized, flags: Markly::SMART | Markly::UNSAFE | Markly::HARD_BREAKS, extensions: [:table, :tasklist, :autolink])
-      Obsidian::ParsedMarkdownDocument.new(document, document2)
+      document = Markly.parse(normalized, flags: Markly::SMART | Markly::UNSAFE | Markly::HARD_BREAKS, extensions: [:table, :tasklist, :autolink])
+      Obsidian::ParsedMarkdownDocument.new(document, renderer: renderer)
     end
   end
 end

lib/obsidian/parser/parsed_markdown_document.rb

@@ -2,9 +2,9 @@
 
 module Obsidian
   class ParsedMarkdownDocument
-    def initialize(document, document2)
-      @document2 = document
-      @document = document2
+    def initialize(document, renderer:)
+      @document = document
+      @renderer = renderer
     end
 
     def extract_links
@@ -22,12 +22,13 @@ def extract_links
     end
 
     def to_html
-      @document2.to_html
+      renderer.render(document)
     end
 
     private
 
     attr_reader :document
+    attr_reader :renderer
 
     def _extract_text_content(element)
       if element.type == :text

obsidian-parser.gemspec

@@ -30,8 +30,6 @@ Gem::Specification.new do |spec|
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "kramdown", "~> 2.4"
-  spec.add_dependency "kramdown-parser-gfm", "~> 1.1"
   spec.add_dependency "markly", "~> 0.7.0"
 
   # For more information and examples about making a new gem, check out our

spec/obsidian/parser/parsed_markdown_document_spec.rb

@@ -4,7 +4,7 @@
   let(:index) { nil }
 
   def create_instance(markdown)
-    Obsidian::ObsidianFlavoredMarkdown.parse(markdown, root: index)
+    Obsidian::ObsidianFlavoredMarkdown.parse(markdown, root: index, renderer: HtmlRenderer.new)
   end
 
   it "extracts [foo](bar) links" do
@@ -38,7 +38,7 @@ def create_instance(markdown)
       [bar]: /url "title"
     END
 
-    parsed_document = Obsidian::ObsidianFlavoredMarkdown.parse(markdown)
+    parsed_document = Obsidian::ObsidianFlavoredMarkdown.parse(markdown, renderer: HtmlRenderer.new)
 
     links = parsed_document.extract_links
 

spec/obsidian/parser_spec.rb

@@ -39,7 +39,7 @@
   end
 
   it "converts markdown into HTML content" do
-    expect(parser.pages.find { |note| note.title == "cat" }.content.generate_html).to eq("<h2 id=\"cats-are-the-best\">Cats are the best</h2>\n\n<p>Meow meow meow</p>\n")
+    expect(parser.pages.find { |note| note.title == "cat" }.content.generate_html).to eq("<h2 id=\"cats-are-the-best\">Cats are the best</h2>\n<p>Meow meow meow</p>\n")
   end
 
   it "adds index.md content to index pages" do