How to integrate third party php library css, js and other static files in Magento 2?

[mathanagopal_s]

There is the library which has some css, js assets. I want to include this library and use it's assets in Magento 2. I am prepared to write a module for this, but I don't know where to start.

I first went with the approach of copying the files to lib/web directory, but when it went to magento-cloud the code collapsed as we do not have write access to that folder. Then I stumbled upon the file 'vendor/magento/module-deploy/Source/Lib.php' and tried to recreate it. I was not able to place the files in the static directory and I got the error of 'Unable to resolve the source file'.

My code in the di.xml

    <type name="Magento\Deploy\Source\SourcePool">
        <arguments>
            <argument name="sources" xsi:type="array">
                <item name="customassets" xsi:type="object">*\*\Source\Assets</item>
            </argument>
        </arguments>
    </type>

Assets.php file

<?php

namespace *\*\Source;

use Magento\Deploy\Package\Package;
use Magento\Deploy\Package\PackageFileFactory;
use Magento\Deploy\Source\SourceInterface;
use Magento\Framework\App\Utility\Files;

class Assets implements SourceInterface
{
    const TYPE = 'customassets';
    /**
     * @var Files
     */
    private $filesUtil;
    /**
     * @var PackageFileFactory
     */
    private $packageFileFactory;

    public function __construct(
        Files $filesUtil,
        PackageFileFactory $packageFileFactory
    ) {
        $this->filesUtil          = $filesUtil;
        $this->packageFileFactory = $packageFileFactory;
    }

    public function get(): array
    {
        $files              = [];
        $pattern            = BP . "/vendor/*/*/src/*/*/assets";
        foreach (Files::getFiles([$pattern], '*') as $file) {
            $path          = str_replace(DIRECTORY_SEPARATOR, '/', BP);
            $fileName      = $this->_parseAssets($file, $path);
            $params             = [
                'area'       => Package::BASE_AREA,
                'theme'      => null,
                'locale'     => null,
                'module'     => null,
                'fileName'   => $fileName,
                'sourcePath' => $file
            ];
            $files[]        = $this->packageFileFactory->create($params);
        }


        return $files;
    }

    /**
     * Parse file path from the absolute path of static library
     *
     * @param string $file
     * @param string $path
     *
     * @return string
     */
    protected function _parseAssets(string $file, string $path): string
    {
        preg_match(
            '/^' . preg_quote("{$path}/vendor/*/*/src/*/*/", '/') . '(.+)$/i', $file,
            $matches);

        return 'custom/assets/' . $matches[1];
    }
}