Relative Project Paths

When you want to save assets from scripts in your Unity project, you may often run into an error explaining that you must use relative paths.

This simple class (should) converts all paths into relative paths:

using System;
using System.IO;
using UnityEngine;

namespace Varneon.Editor
{
    public static class PathUtility
    {
        /// <summary>
        /// Converts full path to one relative to the project
        /// </summary>
        /// <param name="path">Full path pointing inside the project</param>
        /// <returns>Path relative to the project</returns>
        /// <exception cref="ArgumentException"/>
        public static string ConvertToRelativePath(string path)
        {
            // If string is null or empty, throw an exception
            if (string.IsNullOrEmpty(path)) { throw new ArgumentException("Invalid path!", nameof(path)); }

            // Get the 'Assets' directory
            string assetsDirectory = Application.dataPath;

            // Get the project's root directory (Trim 'Assets' from the end of the path)
            string projectDirectory = assetsDirectory.Substring(0, assetsDirectory.Length - 6);

            // Ensure that the path is the full path
            path = Path.GetFullPath(path);

            // Replace backslashes with forward slashes
            path = path.Replace('\\', '/');

            // If path doesn't point inside the project, throw an exception
            if (!path.StartsWith(projectDirectory)) { throw new ArgumentException("Path is not located in this project!", nameof(path)); }

            // Return a path relative to the project
            return path.Replace(projectDirectory, string.Empty);
        }
    }
}