Versions of contents

phil/content-bundle keeps the versions of its contents: a published version is frozen, the next edit forks a new one, and a published body keeps its UJO source with its compiled HTML (Body, format ujo). The bundle stores and publishes versions but shows none of them, so there is no screen of its own to plug a difference into; an application that shows the history of a content compares two versions with this library.

Two published versions

Both bodies are UJO: compare them as documents.

use Phil\ContentBundle\Domain\Capability\BodyCapable;
use Phil\TextDiff\TextDiff;
use Phil\Ujo\Ujo;

function bodyDifference(BodyCapable $old, BodyCapable $new, TextDiff $differ, Ujo $ujo): string
{
    $before = $old->getBody();
    $after = $new->getBody();

    if (null === $before || null === $after) {
        return '';
    }

    return $differ->documentToHtml($differ->documents($ujo->decode($before->source), $ujo->decode($after->source)));
}

Pass the application's HtmlRenderer — the one phil/ujo-bundle configures — as the second argument of documentToHtml() so that the difference is rendered like the page.

A draft and a published version

A draft keeps the format of its author: Markdown, BBCode, a wiki syntax, or UJO. Two ways to compare it with the published version:

• as the reader will see it: convert the draft to UJO with the converter of phil/markup-bundle (or the BodyConverter of the content bundle), then compare documents as above. The readers of written formats number blocks in reading order (b1, b2…), so a block inserted near the top renumbers every block after it, and blocks are then paired by position rather than by identity; for such texts, the rendered HTML compares better: $differ->toHtml($differ->html($before->html, $after->html));
• as the author wrote it: when both versions are in the same written format, compare their sources by paragraphs or lines, $differ->paragraphs($before->source, $after->source), and show the result in a pre-wrap element.

Other fields

Titles, summaries and other short texts compare by words, $differ->words(); a value that is not text — a date, a flag — needs no library.