Blackthunder

Blackthunder added customized tags to Blackfriday.

Blackfriday is a Markdown processor implemented in Go. It is paranoid about its input (so you can safely feed it user-supplied data), it is fast, it supports common extensions (tables, smart punctuation substitutions, etc.), and it is safe for all utf-8 (unicode) input.

HTML output is currently supported, along with Smartypants extensions.

It started as a translation from C of Sundown.

Installation

go get github.com/tsuba3/blackthunder

Usage

    tags = map[string]blackthunder.CustomizedTag{}
    tags["red"] = blackthunder.CustomizedTag{
        Parse: func(attr map[string]string, args []string) blackthunder.CTagNode {
            return blackthunder.CTagNode{
                Before: []byte(`<span style="color:red;">`),
                After:  []byte(`</span>`),
            }
        }
    }

    input := []byte(`{red}This is *RED* text.{/red}`)
    output := blackthunder.MarkdownWithCustomizedTag(input, tags)
    // output:
    // <p><span style="color:red;">This is <em>RED</em> text.</span></p>

Sanitize untrusted content

Blackthunder itself does nothing to protect against malicious content. If you are dealing with user-supplied markdown, we recommend running blackthunder's output through HTML sanitizer such as Bluemonday.

Here's an example of simple usage of blackthunder together with bluemonday:

import (
    "github.com/tsuba3/blackthunder"
    "github.com/russross/blackfriday"
)

// ...
unsafe := blackfriday.MarkdownWithCustomizedTag(input, tag)
html := bluemonday.UGCPolicy().SanitizeBytes(unsafe)

Features

All features and syntax of blackfriday are supported.

Customized tags

A customized tag is like XHTML tags e.g.
{name key=value 0}...{/name}
key=value is an attribute. 0 is an argument.
A tag without children like {name /} requires to end with /}.

tags = map[string]blackthunder.CustomizedTag{}
tags["red"] = blackthunder.CustomizedTag{
    Async: false, // if true, Parse will run async
    Parse: func(attr map[string]string, args []string) blackthunder.CTagNode {
        return blackthunder.CTagNode{
            Before: []byte(`<span style="color:red;">`),
            After:  []byte(`</span>`),
        }
    }
}

Parse function recieve attributes and arguments and return CTagNode. CTagNode is

type CTagNode struct {
	IsBlock bool // Block will not be wrapped by <p>

	Child map[string]CustomizedTag // Tags available in children

	// For tags with children
	Before []byte // before children
	After  []byte // after children

	// For tags without children
	Content []byte
}

License

Blackthunder is distributed under the Simplified BSD License