Flow Query Replacement

[bwaidelich]

Disclaimer: This issue is merely a collection of ideas, I don't think that we have to replace FlowQuery in the core as this can be explored with 3rd party packages first

While FlowQuery served us well in the past, it has some major drawbacks:

• PHP API is not type-safe and quite cumbersome
• Most operations act on result sets in memory. This leads to crazy RAM consumptions if not carefully worked around
• It's not aware of (Fusion) caches, getting the @cache config right can be a difficult challenge

Some ideas

• A PHP "Query Builder" that builds an AST that can be evaluated lazily to produce the most effective ContentGraph interactions when accessed
• A helper that can extract @cache config from this AST
• Maybe based on the Cypher query language (but only if that turns out to be a good fit)

[mhsdesign]

Just that it doesnt get lost:

Following things were already experimented with:

Sitegeist.CriQuel

-> package https://github.com/sitegeist/Sitegeist.CriQuel

from @mficzel

$result = Query::create($documentNode)
  ->chain(new ReferencingNodesProcessor('taxonomyReferences', 'Sitegeist.Taxonomy:Taxonomy'))
  ->chain(new WithDescendantsProcessor('Sitegeist.Taxonomy:Taxonomy'))
  ->chain(new ReferencedByNodesProcessor('taxonomyReferences', 'Neos.Neos:Document'))
  ->chain(new UniqueProcessor())
  ->chain(new RemoveProcessor($documentNode))
  ->extract(new GetNodesExtractor());

or in fusion:

similarDocuments = ${crql(documentNode).referencingNodes('taxonomyReferences', 'Sitegeist.Taxonomy:Taxonomy').withDescendants('Sitegeist.Taxonomy:Taxonomy').referencedByNodes('taxonomyReferences', 'Neos.Neos:Document').unique().remove(documentNode).getNodes()}

Cypher

-> first draft https://github.com/neos/contentrepository-development-collection/tree/cypher

• standard http://opencypher.org/
• testsuite https://github.com/opencypher/openCypher/tree/master/tck
• alternative GQL (Draft) https://www.gqlstandards.org/
• php query builder? https://packagist.org/packages/paulmozo/php-cypher-query-builder

from @nezaniel

-[:ROOT]->(n:Sitegeist.Taxonomy:Vocabulary) for root nodes of type Vocabulary (n: {nodeAggregateId: 'org-starfleet-starfleetcommand'}) for a node by id