A simple example of framework-less PHP rendering templates to add translations (or any other dynamic content)

render_templates.php

<?php
//Clean previous built files
array_map('unlink', glob(__DIR__ . '/public/*.html'));
array_map('unlink', glob(__DIR__ . '/public/pt-br/*.html'));
array_map('unlink', glob(__DIR__ . '/public/de/*.html'));
array_map('unlink', glob(__DIR__ . '/public/jp/*.html'));

//Scan for all templates
$templates = glob(__DIR__ . '/renderer/templates/*.php');;
$locales = glob(__DIR__ . '/renderer/locales/*.php');;

foreach ($templates as $templateFile) {
    foreach ($locales as $localeFile) {
        $renderedPage = renderPage($localeFile, $templateFile);
        saveRenderedFile($templateFile, $localeFile, $renderedPage);
    }
}

function renderPage($localeFile, $templateFile)
{
    ob_start();
    //Include translations
    include $localeFile;
    //Render the template itself
    include $templateFile;
    $contents = ob_get_contents();
    ob_end_clean();

    return $contents;
}

function saveRenderedFile($templateFile, $localeFile, $contents){
    $pageName = stripFilePath($templateFile);
    $languageName = stripFilePath($localeFile);
    
    if ($languageName == 'en') {
        $fileDestination = __DIR__ . '/public/' . $pageName . '.html';
    } else {
        $fileDestination = __DIR__ . '/public/' . $languageName . '/' . $pageName . '.html';
    }

    //Save the output to the right file
    file_put_contents($fileDestination, $contents);
    echo $pageName . '.html concluded for language ' . $languageName . PHP_EOL;
}

function stripFilePath($filePath)
{
    return str_replace('.php', '', basename($filePath));
}