cr-cmark-gfm v0.1.3
cr-cmark-gfm
Crystal C bindings for cmark-gfm, with support for Github Flavored Markdown (v0.29.0.gfm.8). For more information regarding the available options and extensions see the official GFM spec documentation.
Features:
- Simple parsing and rendering of markdown content
- Render any node of the markdown AST in the following formats:
- HTML
- XML
- Plaintext
- Commonmark (including GFM-only nodes)
- Groff man pages
- LaTeX
- Create custom renderers or customize the included crystal HTML renderer, which outputs the same HTML as the library's C renderer
- Getters and setters for almost all of the properties of AST nodes
- Tree traversal and manipulation
- Directly create and customize nodes
Installation
Add the dependency to your shard.yml
and then run shards install
:
dependencies:
cmark:
github: amauryt/cr-cmark-gfm
version: ~> 0.1.3
This will automatically clone the cmark-gfm repository and compile both libcmark-gfm
and libcmark-gfm-extensions
, which can then be statically linked.
Usage
The Cmark
module offers high-level parsing and rendering of markdown content, be it Commonmark-only, full GFM, or partially GFM.
If the content is Commonmark-only use the respective commonmark parsing and HTML rendering methods for the best performance. If all of the GFM extensions must be enabled use the gfm methods. For partial support of GFM extensions use the more generic document methods.
require "cmark"
options = Option.flags(Nobreaks, ValidateUTF8) # deafult is Option::None
extensions = Extension.flags(Table, Tasklist) # default is Extension::None
commonmark_only = File.read("commonmark_only.md")
full_gfm = File.read("full_gfm.md")
partially_gfm = File.read("partially_gfm.md")
# Direct parsing and rendering
commonmark_only_html = Cmark.commonmark_to_html(commonmark_only, options)
full_gfm_html = Cmark.gfm_to_html(full_gfm, options)
partially_gfm_html = Cmark.document_to_html(partially_gfm, options, extensions)
# Parse to obtain a document node for further processing
commonmark_only_node = Cmark.parse_commonmark(commonmark_only, options)
full_gfm_node = Cmark.parse_gfm(full_gfm, options)
partially_gfm_node = Cmark.parse_document(partially_gfm, options, extensions)
Node creation and rendering
require "cmark"
include Cmark
contents = NodeMaker.strong
contents.append_child NodeMaker.text("click here")
node = NodeMaker.link(url: "http://example.com", title: "Example")
node.append_child(contents)
node.type.link? # => true
node.url # => http://example.com
node.title # => "Example"
node.title = "My Example"
node.render_commonmark # => [**click here**](http://example.com "My Example")
node.render_plaintext # => click here
Tree traversal and manipulation
# Using the node from the previous example
node.previous # => nil
node.first_child # => <Cmark::Node::Strong>
last_child = node.last_child.not_nil!
last_child == node.first_child # => true
last_child.next # => <Cmark::Node::Text>
iterator = EventIterator.new(node)
iterator.each do |event|
node = event.node
if event.enter?
puts "entering node"
end
if event.modifiable? && node.type.strong?
# Transform strong text into unformatted text
text_node = node.first_child.not_nil!
node.parent.not_nil!.prepend_child(text_node)
node.unlink
end
end
node.render_commonmark # => [click here](http://example.com "My Example")
Custom rendering
class MyHTMLRenderer < Cmark::HTMLRenderer
# Container nodes receive `node` and `entering`
def strong(node, entering)
if entering
out "<b>"
else
out "</b>"
end
end
# Leaf nodes only receive `node`
def text(node)
out node.literal.gsub("click", "don't click")
end
end
# Using the node from the "Node creation and rendering" example
options = Option.flags(Nobreaks, ValidateUTF8) # default is Option::None
extensions = Extension.flags(Table, Tasklist) # default is Extension::None
renderer = MyHTMLRenderer.new(options, extensions)
html = renderer.render(node)
html # => <a href="http://example.com" title="My Example"><b>don't click here</b></a>
Alternatives
Other alternatives (from which this shard took inspiration) are:
- markd: A pure Crystal port of commonmark.js. Compliant to Commonmark v0.29, but it has no GFM support.
- crystal-cmark: Minimal parsing and rendering C bindings with cmark v0.30.2 but without GFM support.
- crystal-cmark-gfm: Minimal C bindings for parsing and rendering with the latest commit of cmark-gfm (v0.29.0.gfm.x)
Contributing
- Fork it (https://github.com/amauryt/cr-cmark-gfm/fork)
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create a new Pull Request
Contributors
- Amaury Trujillo - creator and maintainer
- Anton Maminov - contributor
cr-cmark-gfm
- 20
- 4
- 0
- 9
- 0
- about 1 month ago
- October 14, 2019
BSD 2-Clause "Simplified" License
Sat, 23 Nov 2024 13:43:15 GMT