Helper class to deal with placeholders and XML or HTML tags which should be replace in given text.

TemplateTranslation.php

<?php

/**
 * Helper class to deal with placeholders and xml tags which should be replace in given text
 *
 * ---------- Example ----------
 * $sampleText = 'This is the <bold-underline>sample</bold-underline> code of {{user}}'.
 * $placeholders = ['user' => 'Mohammed Mudassir'];
 * $xml = ['bold-underline' => '<b style="text-decoration: underline'>%</b>']
 *
 * $templateTranslation = new TemplateTranslation($placeholders, $xml);
 * echo $template->process($sampleText);
 * ---------- Example ----------
 *
 * @author Mohammed Mudassir <hello@mudasir.me>
 */
class TemplateTranslation
{
    /** @var array */
    protected $xml;

    /** @var array */
    protected $placeholders;

    /**
     * @param array $placeholders
     * @param array $xml
     */
    public function __construct(array $placeholders = [], array $xml = [])
    {
        $this->placeholders = $placeholders;
        $this->xml = $xml;
    }

    /**
     * @param string $key
     * @return string
     */
    public function process(string $key)
    {
        return $this->processXml($this->processTags(__($key)));
    }

    /**
     * XML are static values which get replace by system define HTML tag such as <style_link_1>text</style_link_1>
     * Note: tags starts and ends like a HTML tag
     *
     * @param string $text
     * @param array $xml
     * @return string
     */
    public function processXml(string $text, $xml = []): string
    {
        $expressions = [];

        foreach (array_merge($this->xml, $xml) as $tag => $value) {
            if (empty($tag)) {
                continue;
            }

            $expressions["/<{$tag}>(.+)<\/{$tag}>/iU"] = str_replace('>%<', '>$1<', $value);
        }

        return preg_replace(array_keys($expressions), array_values($expressions), $text);
    }

    /**
     * Tags are dynamic values which need to get replace by a placeholder such as {{click_link}}
     * Note: tags starts with double parentheses
     *
     * @param string $text
     * @param array $placeholders
     * @return string
     */
    public function processTags(string $text, $placeholders = []): string
    {
        $placeholders = array_merge($this->placeholders, $placeholders);

        return preg_replace_callback('/(?>{{(?<placeholder>.*)}})+/iU', function (array $match) use ($placeholders) {
            return array_get($placeholders, strtolower(trim((string)$match['placeholder'])));
        }, $text);
    }

}