UJO documents

When phil/ujo-bundle is installed and ujo.enabled is true (the default), the bundle decorates the Phil\Ujo\Html\HtmlRenderer service: withCodeHighlighter() gives its code blocks the highlighter. Everything that renders through that service is coloured: Ujo::toHtml(), the ujo_html filter and function, the formats of phil/markup-bundle read into UJO, and code that injects the renderer.

{{ article.body|ujo_html }}
{# <pre class="ujo-code"><code class="language-php"><span class="hl-variable">$a</span> … </code></pre> #}

The renderer of phil/ujo keeps the coloured HTML only when it holds nothing but the code's text, escaped, inside <span class="…"> elements; any other HTML falls back to the escaped code, so the document stays purified by construction. A block with no language, or with one the highlighter does not know, is written as escaped text with its language-… class, for the highlight controller of phil/ux-bundle to try in the browser; a block already coloured on the server is left alone there.

The decoration composes with the others on the same service, such as the typographic pass of phil/typography-bundle, whose typographer never changes the text of pre and code.

Through a purifier

phil/markup's SanitizerPurifier keeps the hl-… classes on span at the levels that keep spans, and the language-… class on code at every level: HTML purified at all keeps its colours, at forum its text.

Switching it off

phil_highlight:
    ujo: false

The code blocks are then escaped text with their language-… class, as phil/ujo writes them. Without phil/ujo-bundle, the code highlighter is removed when the container is compiled, and nothing is decorated.