!!! TASK: Remove deprecated Fusion prototypes

[mficzel]

The following Fusion prototypes were deprecated for a long time and have been removed. While the documentation has been removed a section "Removed Fusion Prototypes" is added to the reference that mentions the old names and their replacements.

• Neos.Fusion:Array has been removed in favor of Neos.Fusion:Join
• Neos.Fusion:RawArray has been removed in favor of Neos.Fusion:DataStructure
• Neos.Fusion:Collection has been removed in favor of Neos.Fusion:Loop
• Neos.Fusion:RawCollection has been removed in favor of Neos.Fusion:Map
• Neos.Fusion:Attributes as been removed in favor of the property attributes in Neos.Fusion:Tag

The prototype Neos.Fusion:UriBuilder is deprecated aswell but not as long as the others. The fusion file was moved to the deprecated folder and the documentation was moved to the deprecated section.

Resolves: #4538

Upgrade instructions

The following prototypes have to be replaced as mentioned.

• Neos.Fusion:Array replace with Neos.Fusion:Join
• Neos.Fusion:RawArray replaced with Neos.Fusion:DataStructure
• Neos.Fusion:Collection replaced with Neos.Fusion:Loop and the property children has to be renamed to items
• Neos.Fusion:RawCollection replaced with Neos.Fusion:Map and the property children has to be renamed to items
• Neos.Fusion:Attributes replaced by the property attributes in Neos.Fusion:Tag

The prototype Neos.Fusion:UriBuilder should be replaced with Neos.Fusion:ActionUri but will
still work for now.

Since renaming of children to items may not always be obvious in cases where inheritance is used the following line
can add a fallback from items to children:

prototype(Neos.Fusion:Map) {
    items = ${this.children}
}
prototype(Neos.Fusion:Loop) {
    items = ${this.children}
}

Review instructions

Checklist

• Code follows the PSR-2 coding style
• Tests have been created, run and adjusted as needed
• The PR is created against the lowest maintained branch
• Reviewer - PR Title is brief but complete and starts with FEATURE|TASK|BUGFIX
• Reviewer - The first section explains the change briefly for change-logs
• Reviewer - Breaking Changes are marked with !!! and have upgrade-instructions

[mficzel]

Maybe we should add a migration to do the basic renaming. The change from Collection -> children to Loop -> items cannot be migrated easyly but everything else could.

Question would be rector or classic code migration.

[mhsdesign]

@mficzel i might have an idea to do a full migration of all the prototypes correctly including "collection" to "items" ... but i want to discuss this with you first ;)

[mficzel]

i might have an idea

I like and am curious. If this would be a rector based solution it should not stop this pr from beeing merged.
Also it would imho be fine to migrate

test = Neos.Fusion:RawCollection {
   ... 
}

to

# @todo the key `children` has to be renamed to `items` which cannot be done automatically
test = Neos.Fusion:Map {
   ... 
}

[mhsdesign]

On the other hand even in the biggest client project i only have around 80 matches when looking for the legacy "collection" fusion key.

i used this regex to ignore ${this.collection} and {props.collection} in the results:

(?<!\$?\{.*)\bcollection\b

of course there are many false positives that need to be ignored (because some component uses the collection prop itself, but id say its way safer and more pragmatic to migrate those cases by hand. (same for children to items ...)

My suggested automated way would throw away all fusion comments and reformat the code ... or we first have to adjust the parsing ...

[mficzel]

In here it makes sense mostly to decide wether we want a rector migration or not as this would be a separate pr with room for discussion. In here we could only add classic code-migrations.

[jonnitto]

So much code has been deleted. I like

[manuelmeister]

Will look at the updated documentation for this, to ensure everything is beginner friendly (with keeping in mind that legacy code examples are floating around the web)

[mhsdesign]

Looks good!

I couldnt find any left overs in the codebase.

[mhsdesign]

Found some old fusion inside the neos ui e2e tests which needs to be adjusted ^^ https://github.com/neos/neos-ui/tree/9.0/Tests/IntegrationTests/TestDistribution/DistributionPackages

[manuelmeister]

I think the Fusion Reference should be rewritten as well. Currently there are several places where references to old prototypes are made. The wording for DataStructure may profit from mentioning that this is probably the "real" array type someone might be looking for.