Nullable value for suggest field about django-elasticsearch-dsl-drf HOT 2 CLOSED

from django_elasticsearch_dsl_drf.compat import get_elasticsearch_version

MAJOR = get_elasticsearch_version()[0]

# Why do we need to have an empty value for ``VALUE_NOT_SPECIFIED``? As of
# Elastic 5.x, all fields that are used in completion do not allow empty
# values. Therefore, we have to use this trick.
if MAJOR > 2:
    VALUE_NOT_SPECIFIED = " " 
else:
    VALUE_NOT_SPECIFIED = ""

from django_elasticsearch_dsl import DocType, Index, fields
from django_elasticsearch_dsl_drf.compat import KeywordField, StringField

@INDEX.doc_type
class ArticleDocument(DocType):
    """Article Elasticsearch document."""

    title = StringField(
        analyzer=html_strip_lowercase,
        fields={
            'raw': KeywordField(),
            'suggest': fields.CompletionField(),
            'lowercase': StringField(analyzer=keyword_lowercase),
            'dutch': StringField(analyzer='dutch'),
        }
    )

    def prepare_title(self, instance):
        """Prepare title."""
        return instance.title if instance.title else VALUE_NOT_SPECIFIED