go.ngs.io/jplaw2epub

Go library and command line tool to convert Japanese Standard Law XML Schema (法令標準XMLスキーマ) into EPUB files.

go get go.ngs.io/jplaw2epub

Version:: v1.2.0
License:: MIT
Author:: ngs
Repository:: https://github.com/ngs/jplaw2epub
Documentation:: https://pkg.go.dev/go.ngs.io/jplaw2epub
Last Updated:: 2025-08-20T08:25:49Z

jplaw2epub

Go library and command line tool to convert Japanese Standard Law XML Schema (法令標準XMLスキーマ) into EPUB files.

Overview

jplaw2epub is a comprehensive tool for converting Japanese law documents from the official XML format to EPUB e-books. It supports the full Japanese Standard Law XML Schema specification, including all document structures, appendixes, tables, and figures.

Library Usage

package main

import (
    "fmt"
    "os"
    
    "go.ngs.io/jplaw2epub"
)

func main() {
    // Method 1: Create EPUB from XML file path
    book, err := jplaw2epub.CreateEPUBFromXMLPath("law.xml")
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }

    if err := jplaw2epub.WriteEPUB(book, "output.epub"); err != nil {
        fmt.Printf("Error writing EPUB: %v\n", err)
        return
    }

    // Method 2: Create EPUB from io.Reader
    xmlFile, err := os.Open("law.xml")
    if err != nil {
        fmt.Printf("Error opening file: %v\n", err)
        return
    }
    defer xmlFile.Close()

    book2, err := jplaw2epub.CreateEPUBFromXMLFile(xmlFile)
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }

    if err := jplaw2epub.WriteEPUB(book2, "output2.epub"); err != nil {
        fmt.Printf("Error writing EPUB: %v\n", err)
        return
    }

    fmt.Println("EPUB files created successfully!")
}

API Functions

CreateEPUBFromXMLPath(xmlPath string) (*epub.Epub, error) - Creates an EPUB from a file path
CreateEPUBFromXMLFile(xmlFile io.Reader) (*epub.Epub, error) - Creates an EPUB from an io.Reader
WriteEPUB(book *epub.Epub, destPath string) error - Writes an EPUB book to a file

Command Line Usage

Installation

Install the CLI tool:

go install go.ngs.io/jplaw2epub/cmd/jplaw2epub@latest

Or build from source:

git clone https://github.com/ngs/jplaw2epub.git
cd jplaw2epub
go build -o jplaw2epub ./cmd/jplaw2epub

Basic Usage

jplaw2epub -d output.epub input.xml

Command Line Options

-d string
    Destination file path (required)
-no-images
    Skip downloading and embedding images
-max-image-height string
    Maximum image height (e.g., '300px', '80vh', '50%') (default "80vh")

Examples

Convert a law XML file to EPUB:

jplaw2epub -d mylaw.epub path/to/law.xml

Convert without downloading images:

jplaw2epub -no-images -d mylaw.epub path/to/law.xml

Convert with custom image height limit:

jplaw2epub -max-image-height "500px" -d mylaw.epub path/to/law.xml

Installation as Go Library

Add to your Go project:

go get go.ngs.io/jplaw2epub

Features

Document Structure Support

Main Provisions: Chapters, sections, subsections, divisions, and articles
Supplementary Provisions: Full support with chapters, articles, and appendixes
Paragraph Hierarchy: Proper handling of numbered and unnumbered paragraphs
Item Structure: Support for Items, Subitem1, Subitem2, and Subitem3
List Elements: Native list support with proper nesting (List, Sublist1-3)

Appendix Support

AppdxTable: Appendix tables with full table structure
AppdxNote: Appendix notes with structured content
AppdxStyle: Appendix styles with formatting
AppdxFormat: Appendix formats with embedded figures
AppdxFig: Appendix figures with image support

Advanced Features

Ruby Annotations: Full support for Japanese phonetic guides (ルビ)
Table Processing: Complex tables with headers, spans, and borders
Image Embedding: Automatic download and embedding of referenced images
Figure Support: FigStruct and Fig element processing
Style Management: StyleStruct and Format element handling
Dynamic List Styling: Automatic detection (CJK ideographic, katakana-iroha, hiragana-iroha)

Technical Features

High Test Coverage: 71.5% code coverage with comprehensive test suite
Clean Code: Passes all Go linters (gofmt, go vet, golangci-lint)
Modular Architecture: Well-organized code with separate processors for each element type
Error Handling: Robust error handling throughout the conversion process
EPUB Metadata: Full support with Japanese era information
Clean Go API: Simple library interface for programmatic usage
Cross-platform CLI: Command-line tool with binary releases

Data Sources

The tool processes XML files conforming to the Japanese Standard Law XML Schema. You can obtain these files from:

Requirements

Go 1.18 or higher (for building from source)
XML files conforming to Japanese Standard Law XML Schema

Testing

Run the test suite:

go test -v ./...

Generate coverage report:

go test -coverprofile=coverage.out ./...
go tool cover -html=coverage.out

Current test coverage: 71.5%

Development

Building from Source

git clone https://github.com/ngs/jplaw2epub.git
cd jplaw2epub
go build -o jplaw2epub ./cmd/jplaw2epub

Running Linters

# Format code
gofmt -w .

# Check for issues
go vet ./...

# Run comprehensive linting (requires golangci-lint)
golangci-lint run ./...

# Clean up dependencies
go mod tidy

Contributing

Fork the repository
Create your feature branch (git checkout -b feature/amazing-feature)
Commit your changes (git commit -m 'Add some amazing feature')
Push to the branch (git push origin feature/amazing-feature)
Open a Pull Request

Please ensure:

All tests pass (go test ./...)
Code coverage remains above 70%
All linters pass
New features include appropriate tests

Author

Atsushi Nagase

License

MIT License