go-xmlstarlet-validate

Go wrapper for xmlstarlet that allows validating XML documents against XSD, DTD, or RelaxNG schemas. The package supports both filename-based and stream-based validation and returns structured errors with precise positions.

Features

• Validate XML documents against XSD, DTD or RelaxNG
• Validate by file names or io.Reader streams.
• Collect structured validation errors
• Option to stop at the first error

Requirements

• Go 1.20+
• Installed xmlstarlet binary available in $PATH.

---

Installation of xmlstarlet

This package requires the xmlstarlet command-line tool to be available in your $PATH. Check if it is already installed:

xmlstarlet --version

If not, install it depending on your system:

Linux

Most distributions provide it via their package manager:

• Debian / Ubuntu

  sudo apt-get update
  sudo apt-get install xmlstarlet

• Fedora

  sudo dnf install xmlstarlet

• Arch Linux

  sudo pacman -S xmlstarlet

macOS

With Homebrew:

brew install xmlstarlet

Windows

Options:

1. Chocolatey

   choco install xmlstarlet

2. Scoop

   scoop install xmlstarlet

3. Manual

• Download from xmlstar.sourceforge.net
• Extract and add the folder with xmlstarlet.exe to your system PATH.

Installation

go get -u github.com/afansv/go-xmlstarlet-validate@latest

Usage

package main

import (
	"fmt"
	"os"
	"strings"

	validate "github.com/afansv/go-xmlstarlet-validate"
)

func main() {
	// Load schema from file
	xsdFile, _ := os.Open("schema.xsd")
	defer xsdFile.Close()

	schema, err := validate.NewSchemaFromReader(xsdFile, validate.SchemaTypeXSD)
	if err != nil {
		panic(err)
	}
	defer schema.Cleanup()

	// Validate XML string
	xml := `<root><invalid/></root>`
	result, err := validate.ValidateFromReader(schema, strings.NewReader(xml), false)
	if err != nil {
		panic(err)
	}

	if result.Valid {
		fmt.Println("Document is valid")
	} else {
		for _, p := range result.Problems {
			fmt.Printf("%s:%d.%d: %s\n", p.Filename, p.Line, p.Col, p.Issue)
		}
	}
	
	// or
	if err := result.Err(); err != nil {
		fmt.Println(fmt.Errorf("validate xml: %w", err))
	}
}