cmark-writer

A CommonMark writer implementation in Rust.

Basic Usage

use cmark_writer::ast::{Node, ListItem};
use cmark_writer::writer::CommonMarkWriter;

// Create a document
let document = Node::Document(vec![
    Node::heading(1, vec![Node::Text("Hello CommonMark".into())]),
    Node::Paragraph(vec![
        Node::Text("This is a simple ".into()),
        Node::Strong(vec![Node::Text("example".into())]),
        Node::Text(".".into()),
    ]),
]);

// Render to CommonMark
let mut writer = CommonMarkWriter::new();
writer.write(&document).expect("Failed to write document");
let markdown = writer.into_string();

println!("{}", markdown);

Custom Options

use cmark_writer::options::WriterOptionsBuilder;
use cmark_writer::writer::CommonMarkWriter;

// Use builder pattern for custom options
let options = WriterOptionsBuilder::new()
    .strict(true)
    .hard_break_spaces(false)
    .indent_spaces(2)
    .build();

let mut writer = CommonMarkWriter::with_options(options);

Table Support

use cmark_writer::ast::{Node, tables::TableBuilder};

// Create tables with the builder pattern
let table = TableBuilder::new()
    .headers(vec![
        Node::Text("Name".into()), 
        Node::Text("Age".into())
    ])
    .add_row(vec![
        Node::Text("John".into()),
        Node::Text("30".into()),
    ])
    .add_row(vec![
        Node::Text("Alice".into()),
        Node::Text("25".into()),
    ])
    .build();

GitHub Flavored Markdown (GFM)

Enable GFM features by adding to your Cargo.toml:

[dependencies]
cmark-writer = { version = "0.8.0", features = ["gfm"] }

GFM Support:

• Tables with column alignment
• Strikethrough text
• Task lists
• Extended autolinks
• HTML element filtering

HTML Writing

The library provides dedicated HTML writing capabilities through the HtmlWriter class:

use cmark_writer::{HtmlWriter, HtmlWriterOptions, Node};

// Create HTML writer with custom options
let options = HtmlWriterOptions {
    strict: true,
    code_block_language_class_prefix: Some("language-".into()),
    #[cfg(feature = "gfm")]
    enable_gfm: true,
    #[cfg(feature = "gfm")]
    gfm_disallowed_html_tags: vec!["script".into()],
};

let mut writer = HtmlWriter::with_options(options);

// Write some nodes
let paragraph = Node::Paragraph(vec![Node::Text("Hello HTML".into())]);
writer.write_node(&paragraph).unwrap();

// Get resulting HTML
let html = writer.into_string().unwrap();
assert_eq!(html, "<p>Hello HTML</p>\n");

Custom Nodes

use cmark_writer::{HtmlWriteResult, HtmlWriter, Node, WriteResult};
use cmark_writer::writer::InlineWriterProxy;
use cmark_writer::custom_node;
use ecow::EcoString;

#[derive(Debug, Clone, PartialEq)]
#[custom_node(block=false, html_impl=true)]
struct HighlightNode {
    content: EcoString,
    color: EcoString,
}

impl HighlightNode {
    // Implementation for CommonMark output
    fn write_custom(&self, writer: &mut InlineWriterProxy) -> WriteResult<()> {
        writer.write_str("<span style=\"background-color: ")?;
        writer.write_str(&self.color)?;
        writer.write_str("\">")?;
        writer.write_str(&self.content)?;
        writer.write_str("</span>")?;
        Ok(())
    }
    
    // Optional HTML-specific implementation
    fn write_html_custom(&self, writer: &mut HtmlWriter) -> HtmlWriteResult<()> {
        writer.start_tag("span")?;
        writer.attribute("style", &format!("background-color: {}", self.color))?;
        writer.finish_tag()?;
        writer.text(&self.content)?;
        writer.end_tag("span")?;
        Ok(())
    }
}

Development

# Build
cargo build

# Run tests
cargo test

License

This project is licensed under the MIT License - see the LICENSE file for details.