!!! FEATURE: Subtree Tags

[bwaidelich]

This change introduces the concept of Subtree Tags.

Concept

This change allows arbitrary so called Subtree Tags to be attached to nodes.
They are called Subtree Tags because they are always inherited to all descendant nodes.

That makes it possible to attach recursive information to any node which will be an important requirement for security related features but can also be used for other tasks, e.g. related to rendering.

Constraints and properties

• If a node is tagged, all descendant nodes will always inherit this tag
• It's not possible to remove an inherited tag
• It's possible to tag a node with a value that it already inherits (for example: you can mark a child node of a disabled node explicitly disabled, too. If the parent node is re-enabled, the child node and all descendants still stays disabled)
• Vice versa it's possible to tag a node with a value some descendant node(s) is/are already tagged with
• Subtree tag values must be lower case and between 1 and 36 characters long (regex: /^[a-z0-9_.-]{1,36}$/)
• To the core, Subtree tags have no special meaning. With the exception of the disabled tag that leads to the affected nodes to be excluded from subgraph queries in the frontend
• The Node read model exposes its tags including the information whether it is an inherited tag

Usage

Add a subtree tag

$contentRepository->handle(TagSubtree::create(
    $contentStreamId,
    $nodeAggregateId,
    $coveredDimensionSpacePoint,
    NodeVariantSelectionStrategy::STRATEGY_ALL_VARIANTS,
    SubtreeTag::fromString('some_tag'),
));

Remove a subtree tag

$contentRepository->handle(UntagSubtree::create(
    $contentStreamId,
    $nodeAggregateId,
    $coveredDimensionSpacePoint,
    NodeVariantSelectionStrategy::STRATEGY_ALL_VARIANTS,
    SubtreeTag::fromString('some_tag'),
));

Read tags

$node = $subgraph->findNodeById($nodeAggregateId);

// Render all tags of this node (explicit tags bold)
$node->tags->map(fn (SubtreeTag $tag, bool $isInherited) => $this->outputLine(' - %s', [$isInherited ? $tag->value : '<b>' . $tag->value . '</b>']));

Breaking change

This is a breaking change mainly because it extends the Node and Aggregate read models.
Also the NodeHiddenState projection (and its NodeHiddenStateFinder) were replaced, see neos/neos-ui#3741

A projection replay is not required because the deprecated NodeAggregateWasDisabled and NodeAggregateWasEnabled events are automatically up-casted!

Custom projections might have to be reworked if they handled those events!

Next steps

On it's own, this new feature does not bring a whole lot of value (apart from replacing the overly complex restriction edges and the somewhat hacky NodeHiddenStateProjection).
But it will be the foundation for the Neos 9.0 security framework

Resolves: #4550
Related: #3732

Related: neos/neos-ui#3741

[mhsdesign]

Im just wondering if your pr readme is outdated, because

$node->tags->map(fn (SubtreeTag $tag, bool $isInherited) => $this->outputLine(' - %s', [$isInherited ? $tag->value : '<b>' . $tag->value . '</b>']));

doesnt seem to work?

And also i was also wondering why we return a string array if we already have toStringArray

[bwaidelich]

Node::tags is a NodeTags instance, not a SubtreeTags

[mhsdesign]

Ah okay sorry thanks, my brain still holds the old state in memory will have too pull :)

[mhsdesign]

btw we agreed on using yield from $array in these cases ^^

[bwaidelich]

Ah right, feel free to fix!