Builder pattern example in PHP

URLBuilder.php

<?php

class URLBuilder
{
    private $url;
    private $source;
    private $medium;
    private $campaign;
    private $term;

    public function __construct($url)
    {
        $this->url = $url;
    }

    public function setSource($source)
    {
        $this->source = $source;
        return $this;
    }

    public function setMedium($medium)
    {
        $this->medium = $medium;
        return $this;
    }

    public function setCampaign($campaign)
    {
        $this->campaign = $campaign;
        return $this;
    }

    public function setTerm($term)
    {
        $this->term = $term;
        return $this;
    }

    public function build()
    {
        $query = http_build_query([
            'utm_source' => $this->source,
            'utm_medium' => $this->medium,
            'utm_campaign' => $this->campaign,
            'utm_term' => $this->term
        ]);

        return sprintf('%s?%s', $this->url, $query);
    }
}

$utmUrlBuilder = (new URLBuilder('https://www.example.com'))
    ->setSource('blog')
    ->setMedium('any')
    ->setCampaign('summer_sale')
    ->setTerm('shoes');

echo $utmUrlBuilder->build();

// Output: https://www.example.com?utm_source=blog&utm_medium=any&utm_campaign=summer_sale&utm_term=shoes