PHP Templating

Template Engine And Escaping

Respect the template engine already established by the project. Do not replace Twig, Blade, or another existing template engine merely because a different engine would be preferred for a new project. Treat the slim/php-view guidance below as the default only when the project has not already selected a template engine.

For Slim-based projects, prefer slim/php-view with native PHP templates, using its layouts and partials for reuse. Templates must support direct step-by-step debugging with Xdebug without template compilation.

When using slim/php-view:

• Configure the layout on the renderer with $renderer->setLayout('layout.php').
• Render reusable template parts with $this->fetch('partials/contact.php', ['locale' => $locale, 'contact' => $contact]) so their typed input and required rendering context are explicit.
• Do not use APIs from other template engines such as $this->layout(), or bypass PHP-View's partial support with raw include calls.

Escape HTML output explicitly through a shared html(string $value): string helper using htmlspecialchars($value, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8'). Do not apply HTML escaping to plain-text output.

Prefer built-in PHP functionality over additional dependencies when it meets the actual requirements. Introduce another template engine or escaping library only when a concrete requirement justifies it. Handle JavaScript, CSS, and URL contexts separately if they arise.

Start with the framework's simplest suitable option, and justify additional features against actual requirements.