A Laravel file helper class that assists in uploading files to the file server. Stick in app/Helpers or change the namespace to match your project.

FileUploader.php

<?php

namespace App\Helpers;

use RuntimeException;
use Illuminate\Support\Str;
use Illuminate\Support\Facades\File;

/**
 * The file upload helper makes it easier to upload files
 * to the file server
 *
 * @package App\Helpers
 * ----------------------------------------------------------------
 * CONTROLLER USAGE:
 *  $fields = $request->validate([
 *      'file_url' => 'string|nullable'
 *  ]);
 *
 *  if (isset($fields['file_url'])) {
 *      FileUploader::upload($fields['file_url']);
 *  }
 */
class FileUploader
{
    /**
     * Save image in local file system and return saved image path
     *
     * @param string $image      The physical file itself
     * @param string $dir        The directory to upload into
     * @param array  $extensions An array of file extensions
     *
     * @return string
     */
    public static function upload(string $image, string $dir = 'uploads', array $extensions = ['jpg', 'jpeg', 'gif', 'png']): string
    {
        // Check if image is valid base64 string
        if (preg_match('/^data:image\/(\w+);base64,/', $image, $type)) {
            // Take out the base64 encoded text without mime type
            $image = substr($image, strpos($image, ',') + 1);
            // Get file extension
            $type = strtolower($type[1]); // jpg, png, gif

            // Check if file is an image
            if (!in_array($type, $extensions, true)) {
                throw new RuntimeException('invalid image type');
            }
            $image = str_replace(' ', '+', $image);
            $image = base64_decode($image);

            if ($image === false) {
                throw new RuntimeException('base64_decode failed');
            }
        } else {
            throw new RuntimeException('did not match data URI with image data');
        }

        $dir = "$dir/";
        $file = Str::random() . '.' . $type;
        $absolutePath = public_path($dir);
        $relativePath = $dir . $file;
        if (!File::exists($absolutePath)) {
            File::makeDirectory($absolutePath, 0755, true);
        }
        file_put_contents($relativePath, $image);

        return $relativePath;
    }
}