EdgeJgramField django haystack中的min和max字母

Question

有没有办法在django haystack索引中限制edge ngrams的大小？例如,我创建ngram如下:

#search_indexes.py
content_auto = indexes.EdgeNgramField(model_attr='name')

但是我不想创建2个字母的ngrams,我实际上想要将min设置为4或5.

作为背景,我使用django-haystack/elasticsearch,在heroku上使用盆景.

Answer 1

您需要做的是覆盖Haystack的ElasticSearch后端中的搜索映射.

简而言之:扩展ElasticSearch后端并直接替换或settings.py导入新的模式映射.

from django.conf import settings
from haystack.backends.elasticsearch_backend import (ElasticsearchSearchBackend,
    ElasticsearchSearchEngine)

class MyElasticBackend(ElasticsearchSearchBackend):

    def __init__(self, connection_alias, **connection_options):
        super(ConfigurableElasticBackend, self).__init__(
                                connection_alias, **connection_options)
        MY_SETTINGS = {
            'settings': {
                "analysis": {
                    "analyzer": {
                        "ngram_analyzer": {
                            "type": "custom",
                            "tokenizer": "lowercase",
                            "filter": ["haystack_ngram"]
                        },
                        "edgengram_analyzer": {
                            "type": "custom",
                            "tokenizer": "lowercase",
                            "filter": ["haystack_edgengram"]
                        }
                    },
                    "tokenizer": {
                        "haystack_ngram_tokenizer": {
                            "type": "nGram",
                            "min_gram": 3,
                            "max_gram": 15,
                        },
                        "haystack_edgengram_tokenizer": {
                            "type": "edgeNGram",
                            "min_gram": 2,
                            "max_gram": 15,
                            "side": "front"
                        }
                    },
                    "filter": {
                        "haystack_ngram": {
                            "type": "nGram",
                            "min_gram": 3,
                            "max_gram": 15
                        },
                        "haystack_edgengram": {
                            "type": "edgeNGram",
                            "min_gram": 5,
                            "max_gram": 15
                        }
                    }
                }
            }
        }
        setattr(self, 'DEFAULT_SETTINGS', MY_SETTINGS)


class ConfigurableElasticSearchEngine(ElasticsearchSearchEngine):
    backend = MyElasticBackend

有关更全面的解释,请参阅我关于扩展ElasticSearch后端以自定义搜索映射的文章.