EZP-27458: Add Field Facet Visitor

[wizhippo]

Add filed facet support

Example

           new FacetBuilder\FieldFacetBuilder([
                'name' => 'Specialties',
                'fieldPaths' =>['agent/specialties/tag_ids'],
                'limit' => 9999,
            ]),
           
           new FacetBuilder\FieldFacetBuilder([
                'name' => 'Multipath',
                'fieldPaths' => [
                     'article/title',
                     'atrilcle/tags/tag_ids',
                ],
                'limit' => 9999,
           ]),

Related PR ezsystems/ezpublish-kernel#2557

[andrerom]

We would somehow need to make sure we have integration tests in kernel, but besides that Looks like good direction.

[alongosz]

Hmm, indeed some integration test in ezpublish-kernel explaining what happens here would be nice.

Though I see we have some integration tests, which use FieldFacetBuilder, in \eZ\Publish\API\Repository\Tests\SearchServiceTest so I wonder how do they work (maybe there were skipped, or just don't throw when missing builder?).

Anyway this PR will require either more investigation by me before I approve or more explaining in PhpDoc, because code is not self-explanatory.

pinging also our foremost expert in faceted search - @Nattfarinn - for a review :)

[andrerom]

Beside the nitpicks some comments.

Though I see we have some integration tests, which use FieldFacetBuilder, in \eZ\Publish\API\Repository\Tests\SearchServiceTest so I wonder how do they work (maybe there were skipped, or just don't throw when missing builder?).

Afaik skipped, but we should check that they pass here. Ideally Solr tests should be setup to fail on skips to avoid any silent skips happening.

Follow up kernel API design considerations

(NOTE to self / @alongosz, and possibly you @wizhippo if you're up for it)

Besides the need to better document fieldPaths and FieldRangeFacetBuilder->fieldPath:

FieldFacetBuilder->regex

It seems Solr does not allow for regex like the way it's suggested in API. Maybe we should deprecate it, and maybe also consider to add the following if it translates well to Elastic too:

• (string) prefix
• (string) contains
• (bool) containsIgnoreCase = false

[wizhippo]

Any chance the v3 is coming up we can visit this and facets?

[alongosz]

Any chance the v3 is coming up we can visit this and facets?

ping @SylvainGuittard

[SylvainGuittard]

@alongosz I am not against having this in v3.
This PR is against master. Is this branch compatible with Symfony 4 and current eZ Platform v3? Is there any other blocker?

[andrerom]

Is there any other blocker?

@SylvainGuittard Someone in eZ Eng needs to write integration tests in kernel, besides that we are more or less good to go here.

[wizhippo]

Superseded by ezsystems/ezplatform-kernel#94