[Elasticsearch] Filtering on Nested Properties seems to not work

[Cocray]

API Platform version(s) affected: 2.5.3

Description
When filtering on a nested property in ES, we must provide the nested path. Function getNestedFieldPath() in FieldDatatypeTrait.php seems to always return null.

With the example given in your documentation, if we try this filter: /tweets?author.gender=male

author is an object so we enter in this condition:

if (
 Type::BUILTIN_TYPE_OBJECT === $type->getBuiltinType()
 && null !== ($nextResourceClass = $type->getClassName())
 && $this->resourceClassResolver->isResourceClass($nextResourceClass)
) {
 $nestedPath = $this->getNestedFieldPath($nextResourceClass, implode('.', $properties));

 return null === $nestedPath ? $nestedPath : "$currentProperty.$nestedPath";
}

getNestedFieldPath() is called recursively.

gender is the last element of the string, so when we do $currentProperty = array_shift($properties);, $properties is an empty array, so this part returns null:

if (!$properties) {
 return null;
}

$nestedPath is null, so this line return null === $nestedPath ? $nestedPath : "$currentProperty.$nestedPath"; returns null

This part seems to be never called:

if (
 null !== ($type = $type->getCollectionValueType())
 && Type::BUILTIN_TYPE_OBJECT === $type->getBuiltinType()
 && null !== ($className = $type->getClassName())
 && $this->resourceClassResolver->isResourceClass($className)
) {
 return $currentProperty;
}

Thanks

[soyuka]

Hi, Elasticsearch support is still experimental but we do have a test for this use case... I'm not sure how to help you further..

[Cocray]

Hello @soyuka,

I have the problem only when the type in my ES mapping is type=nested. If type=object, it works perfectly. I'll try to give you an example later.

Thanks!

[hhamon]

Hello!

I confirm this problem. We can't filter on nested documents because of what @Cocray explained. Any chance to have a look @meyerbaptiste please?

[colinodell]

$nestedPath is null, so this line return null === $nestedPath ? $nestedPath : "$currentProperty.$nestedPath"; returns null

It is possible that this code should return $currentProperty whenever null === $nestedPath?

 if (
 Type::BUILTIN_TYPE_OBJECT === $type->getBuiltinType()
 && null !== ($nextResourceClass = $type->getClassName())
 && $this->resourceClassResolver->isResourceClass($nextResourceClass)
 ) {
 $nestedPath = $this->getNestedFieldPath($nextResourceClass, implode('.', $properties));
 
- return null === $nestedPath ? $nestedPath : "$currentProperty.$nestedPath";
+ return null === $nestedPath ? $currentProperty : "$currentProperty.$nestedPath";
 }

That would result in this function ultimately returning author as expected.

Hi, Elasticsearch support is still experimental but we do have a test for this use case...
[...]
I have the problem only when the type in my ES mapping is type=nested. If type=object, it works perfectly.

My best guess is that getNestedFieldPath() is returning null within that Behat test, and thus no nested query filter is generated. nested is only needed in the query when working with type=nested mappings, thus the Behat test passes whereas the folks here are seeing issues.

This hunch is further supported by the fact that testApplyWithNestedProperty() unit tests all seem to use collections as the top-level type, not objects, and thus the code path described in the original issue is not covered by them either.

I can work on creating a PR that fixes both this issue and #5642 at the same time (since they both touch the same function)