Django Haystack fix EdgeNGram Analyzer

standard_analyzer_elastic_backend.py

class StandardAnalyzerElasticBackend(ElasticsearchSearchBackend):
    SET_ANALYZE_STANDARD_FOR_SEARCH = getattr(settings, 'SET_ANALYZE_STANDARD_FOR_HAYSTACK_SEARCH', False)
    DEFAULT_SETTINGS = {
        'settings': {
            "analysis": {
                "analyzer": {
                    "ngram_analyzer": {
                        "type": "custom",
                        "tokenizer": "standard",
                        "filter": ["haystack_ngram", "lowercase"]
                    },
                    "edgengram_analyzer": {
                        "type": "custom",
                        "tokenizer": "standard",
                        "filter": ["haystack_edgengram", "lowercase"]
                    }
                },
                "tokenizer": {
                    "haystack_ngram_tokenizer": {
                        "type": "nGram",
                        "min_gram": 3,
                        "max_gram": 15,
                    },
                    "haystack_edgengram_tokenizer": {
                        "type": "edgeNGram",
                        "min_gram": 1,
                        "max_gram": 26,
                        "side": "front"
                    }
                },
                "filter": {
                    "haystack_ngram": {
                        "type": "nGram",
                        "min_gram": 3,
                        "max_gram": 15
                    },
                    "haystack_edgengram": {
                        "type": "edgeNGram",
                        "min_gram": 1,
                        "max_gram": 26
                    }
                }
            }
        }
    }

    def build_search_kwargs(self, query_string, **kwargs):
        search_kwargs = super(StandardAnalyzerElasticBackend, self).build_search_kwargs(query_string, **kwargs)
        if self.SET_ANALYZE_STANDARD_FOR_SEARCH:
            try:
                search_kwargs['query']['filtered']['query']['query_string']['analyzer'] = 'standard'
            except KeyError:
                pass

        return search_kwargs


class StandardAnalyzerElasticSearchEngine(ElasticsearchSearchEngine):
    backend = StandardAnalyzerElasticBackend