html2block

A Go library to convert HTML strings into a structured, JSON-friendly "Block" format.

Overview

html2block parses HTML and transforms it into a tree of structured objects (blocks). This format is ideal for systems that need a clean, predictable representation of rich text and layout without the complexities of raw HTML.

Installation

go get github.com/subiz/html2block

Usage

package main

import (
	"fmt"
	"encoding/json"
	"github.com/subiz/html2block"
)

func main() {
	html := `<div><h1>Hello World</h1><p>This is <b>bold</b> text.</p></div>`
	block := html2block.HTML2Block(html)

	b, _ := json.MarshalIndent(block, "", "  ")
	fmt.Println(string(b))
}

Features

• Standard Tags: Supports div, p, h1-h8, a, img, table, ul, ol, li, etc.
• Formatting: Detects and preserves bold, italic, underline, and strike through both tags (<b>, <i>, etc.) and inline CSS (font-weight, etc.).
• Style Extraction: Extracts a specific subset of CSS attributes (e.g., color, background, margin-top) into a style map.
• Attribute Mapping: Preserves HTML attributes in an attrs map.
• Block Collapsing: Automatically simplifies the structure (e.g., merging nested paragraphs, converting single-child spans to text nodes).
• Emoji & Mentions: Specialized handling for Lexical-style emojis and data-driven mentions/dynamic fields.

Development

To run the tests:

go test -v .