Custom Serialization Groups & Access To Root Entity Class On Normalization

[kiler129]

• Symfony version: 4.2.1
• Algolia Search Bundle version: 3.4.0
• Algolia Client Version: 1.28.0
• Language Version: 7.3.1

Description

Currently normalizers are called with a special searchableArray format. However this is still not enough, since you can only determine if the data is serialized for Algolia or for different purpose (e.g. API-Platform). There's no way (or I don't see it) to support such structure:

[books_index] (e.g. for autocomplete)
 | - book1
 |    | - title: Foo Bar
 |    | - author: John Doe
 |    \ - readers: 124
 \ - book2
      | - title: Baz Bat
      | - author: Josh A.
      \ - readers: 222
 
[categories]
 | - category1
     | - name: Good Books
      \ - promoted
          | - book1
          |    | - title: Foo Bar
          |    \ - author: John Doe
          \ - book2
               | - title: Baz Bat
               \ - author: Josh A.

This is a synthetic example, but the problem has a real business use-case. If you have collection of items you cannot get a basic version of an entity for collections and advanced version of the same entity for a separate index.

This is kind of related to #139, but I basically need to differentiate between nested objects and top level indexes.

Solutions

I see two ways of making this experience better - first is intermittent but very simple and second is advanced but flexible and easily extensible:

Pass index entity in context

normalize() receives $context array. In this array we can add class name of the currently processed index. With such construction normalize() method may look like:

    public function normalize($object, $format = null, array $context = [])
    { 
        $result = $this->normalizer->normalize($object, $format, $context);
        if ($context['rootEntity'] === Book::class) {
            $result['readers'] = $this->doSomeExpensiveCalculations();
        }
        //...
    }

(of course properly it should be a separate normalizer which delegates via composition etc but I skipped this for simplicity)

This can be added literally in 5 minutes (let me know - I can submit PR) by modifying SearchableEntity::getSearchableArray() to call $context['rootEntity'] = \get_class($this->entity).

Allow defining normalization groups

This is a proper solution for the problem. Currently there's a blanket searchable group passed. This is good when I want to decide what goes to search engine and what not, however I cannot have multiple groups depending on the index.

This could be defined as follow:

algolia_search:
    indices:
        - name: books
          class: ACME\Entity\Book
          enable_serializer_groups: true
          serializer_groups:
            - searchable
            - searchableMainBookRoot
        - name: categories
          class: ACME\Entity\Category
          enable_serializer_groups: true
          serializer_groups:
            - searchable
            - searchableMainBookChild

Implementing this will require plugging into SearchableEntity::getSearchableArray() and changing how configuration is parsed to get this extra list. All in all it doesn't seem like a lot more work.

Conclusion

RFC ;) Maybe I don't understand something, but I think in a current state what I need is not possible.