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django-haystack 全文检索配置

一. 使用的工具

  • haystack 是 django的开源搜索框架,该框架支持 Solr, Elasticsearch, Whoosh, *Xapian*搜索引擎,不用更改代码,直接切换引擎,减少代码量。
  • 搜索引擎使用 whoosh,这是一个由纯 Python 实现的全文搜索引擎,没有二进制文件等,比较小巧,配置比较简单,当然性能自然略低。
  • 中文分词 Jieba,由于 Whoosh 自带的是英文分词,对中文的分词支持不是太好,故用 jieba 替换 whoosh 的分词组件。
  • 环境:Python 3.6.8, django 1.11.22, django-haystack 2.6.1, win7 x64

二. 配置过程

本人项目 app结构如图:(目的只是检索 文章 的标题 和 内容)

# models.py

# 主题表/文章表
class Article(models.Model):
    author = models.ForeignKey(User, related_name="author_set", verbose_name="作者", on_delete=models.DO_NOTHING)
    title = models.CharField(max_length=128, verbose_name="标题")
    content = RichTextUploadingField(verbose_name="内容", config_name='awesome_ckeditor')

1. 首先安装各工具

pip install whoosh django-haystack jieba

2. 添加 Haystack 到 项目的 settings.py 的  INSTALLED_APPS

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'haystack',  # Added. haystack先添加,自己的app要写在haystakc后面
    'blog',
    # ...
]

3. 配置结巴分词引擎

将 whoosh 库 下面的 whoosh_backend.py(该文件路径为 python路径/lib/python3.5/site-packages/haystack/backends/whoosh_backend.py拷贝到 app下面,并重命名为 whoosh_cn_backend.py,例如blog/whoosh_cn_backend.py。修改的内容如下:

from jieba.analyse import ChineseAnalyzer  # 结巴分词

# 注意先找到这个再修改,而不是直接添加,第 163 行左右,class WhooshSearchBackend -> def build_schema -> 第一个 for -> 第一个 else 下面
schema_fields[field_class.index_fieldname] = TEXT(stored=True, analyzer=ChineseAnalyzer(),field_boost=field_class.boost, sortable=True)

4. 修改 settings.py,以配置引擎

# HAYSTACK CONFIGS
HAYSTACK_CONNECTIONS = {
    'default': {
        # 'ENGINE': 'haystack.backends.whoosh_backend.WhooshEngine',  # 使用默认引擎
        'ENGINE': 'blog.whoosh_cn_backend.WhooshEngine',  # 自定义引擎,app名称.分词文件名称.WhooshEngine
        'PATH': os.path.join(os.path.dirname(__file__), 'whoosh_index'),
    },
}

# HAYSTACK, 当添加、修改、删除数据时,自动生成索引
HAYSTACK_SIGNAL_PROCESSOR = 'haystack.signals.RealtimeSignalProcessor'

# HAYSTACK, 设置搜索结果页每页显示的数目,默认为20,可以自己修改
HAYSTACK_SEARCH_RESULTS_PER_PAGE = 10

# HAYSTACK, Handle a user-defined highlighting function. 处理用户定义的突出显示函数
HAYSTACK_CUSTOM_HIGHLIGHTER = "blog.templatetags.highlighting.Highlighter"

# whoosh_cn_backend.py

# encoding: utf-8

from __future__ import absolute_import, division, print_function, unicode_literals

import json
import os
import re
import shutil
import threading
import warnings

from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.utils import six
from django.utils.datetime_safe import datetime
from django.utils.encoding import force_text

from haystack.backends import BaseEngine, BaseSearchBackend, BaseSearchQuery, EmptyResults, log_query
from haystack.constants import DJANGO_CT, DJANGO_ID, ID
from haystack.exceptions import MissingDependency, SearchBackendError, SkipDocument
from haystack.inputs import Clean, Exact, PythonData, Raw
from haystack.models import SearchResult
from haystack.utils import log as logging
from haystack.utils import get_identifier, get_model_ct
from haystack.utils.app_loading import haystack_get_model
from jieba.analyse import ChineseAnalyzer  # 结巴分词

try:
    import whoosh
except ImportError:
    raise MissingDependency("The 'whoosh' backend requires the installation of 'Whoosh'. Please refer to the documentation.")

# Handle minimum requirement.
if not hasattr(whoosh, '__version__') or whoosh.__version__ < (2, 5, 0):
    raise MissingDependency("The 'whoosh' backend requires version 2.5.0 or greater.")

# Bubble up the correct error.
from whoosh import index
from whoosh.analysis import StemmingAnalyzer
from whoosh.fields import ID as WHOOSH_ID
from whoosh.fields import BOOLEAN, DATETIME, IDLIST, KEYWORD, NGRAM, NGRAMWORDS, NUMERIC, Schema, TEXT
from whoosh.filedb.filestore import FileStorage, RamStorage
from whoosh.highlight import highlight as whoosh_highlight
from whoosh.highlight import ContextFragmenter, HtmlFormatter
from whoosh.qparser import QueryParser
from whoosh.searching import ResultsPage
from whoosh.writing import AsyncWriter


DATETIME_REGEX = re.compile('^(?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2})T(?P<hour>\d{2}):(?P<minute>\d{2}):(?P<second>\d{2})(\.\d{3,6}Z?)?$')
LOCALS = threading.local()
LOCALS.RAM_STORE = None


class WhooshHtmlFormatter(HtmlFormatter):
    """
    This is a HtmlFormatter simpler than the whoosh.HtmlFormatter.
    We use it to have consistent results across backends. Specifically,
    Solr, Xapian and Elasticsearch are using this formatting.
    """
    template = '<%(tag)s>%(t)s</%(tag)s>'


class WhooshSearchBackend(BaseSearchBackend):
    # Word reserved by Whoosh for special use.
    RESERVED_WORDS = (
        'AND',
        'NOT',
        'OR',
        'TO',
    )

    # Characters reserved by Whoosh for special use.
    # The '\\' must come first, so as not to overwrite the other slash replacements.
    RESERVED_CHARACTERS = (
        '\\', '+', '-', '&&', '||', '!', '(', ')', '{', '}',
        '[', ']', '^', '"', '~', '*', '?', ':', '.',
    )

    def __init__(self, connection_alias, **connection_options):
        super(WhooshSearchBackend, self).__init__(connection_alias, **connection_options)
        self.setup_complete = False
        self.use_file_storage = True
        self.post_limit = getattr(connection_options, 'POST_LIMIT', 128 * 1024 * 1024)
        self.path = connection_options.get('PATH')

        if connection_options.get('STORAGE', 'file') != 'file':
            self.use_file_storage = False

        if self.use_file_storage and not self.path:
            raise ImproperlyConfigured("You must specify a 'PATH' in your settings for connection '%s'." % connection_alias)

        self.log = logging.getLogger('haystack')

    def setup(self):
        """
        Defers loading until needed.
        """
        from haystack import connections
        new_index = False

        # Make sure the index is there.
        if self.use_file_storage and not os.path.exists(self.path):
            os.makedirs(self.path)
            new_index = True

        if self.use_file_storage and not os.access(self.path, os.W_OK):
            raise IOError("The path to your Whoosh index '%s' is not writable for the current user/group." % self.path)

        if self.use_file_storage:
            self.storage = FileStorage(self.path)
        else:
            global LOCALS

            if getattr(LOCALS, 'RAM_STORE', None) is None:
                LOCALS.RAM_STORE = RamStorage()

            self.storage = LOCALS.RAM_STORE

        self.content_field_name, self.schema = self.build_schema(connections[self.connection_alias].get_unified_index().all_searchfields())
        self.parser = QueryParser(self.content_field_name, schema=self.schema)

        if new_index is True:
            self.index = self.storage.create_index(self.schema)
        else:
            try:
                self.index = self.storage.open_index(schema=self.schema)
            except index.EmptyIndexError:
                self.index = self.storage.create_index(self.schema)

        self.setup_complete = True

    def build_schema(self, fields):
        schema_fields = {
            ID: WHOOSH_ID(stored=True, unique=True),
            DJANGO_CT: WHOOSH_ID(stored=True),
            DJANGO_ID: WHOOSH_ID(stored=True),
        }
        # Grab the number of keys that are hard-coded into Haystack.
        # We'll use this to (possibly) fail slightly more gracefully later.
        initial_key_count = len(schema_fields)
        content_field_name = ''

        for field_name, field_class in fields.items():
            if field_class.is_multivalued:
                if field_class.indexed is False:
                    schema_fields[field_class.index_fieldname] = IDLIST(stored=True, field_boost=field_class.boost)
                else:
                    schema_fields[field_class.index_fieldname] = KEYWORD(stored=True, commas=True, scorable=True, field_boost=field_class.boost)
            elif field_class.field_type in ['date', 'datetime']:
                schema_fields[field_class.index_fieldname] = DATETIME(stored=field_class.stored, sortable=True)
            elif field_class.field_type == 'integer':
                schema_fields[field_class.index_fieldname] = NUMERIC(stored=field_class.stored, numtype=int, field_boost=field_class.boost)
            elif field_class.field_type == 'float':
                schema_fields[field_class.index_fieldname] = NUMERIC(stored=field_class.stored, numtype=float, field_boost=field_class.boost)
            elif field_class.field_type == 'boolean':
                # Field boost isn't supported on BOOLEAN as of 1.8.2.
                schema_fields[field_class.index_fieldname] = BOOLEAN(stored=field_class.stored)
            elif field_class.field_type == 'ngram':
                schema_fields[field_class.index_fieldname] = NGRAM(minsize=3, maxsize=15, stored=field_class.stored, field_boost=field_class.boost)
            elif field_class.field_type == 'edge_ngram':
                schema_fields[field_class.index_fieldname] = NGRAMWORDS(minsize=2, maxsize=15, at='start', stored=field_class.stored, field_boost=field_class.boost)
            else:
                # schema_fields[field_class.index_fieldname] = TEXT(stored=True, analyzer=StemmingAnalyzer(), field_boost=field_class.boost, sortable=True)
                schema_fields[field_class.index_fieldname] = TEXT(stored=True, analyzer=ChineseAnalyzer(), field_boost=field_class.boost, sortable=True)

            if field_class.document is True:
                content_field_name = field_class.index_fieldname
                schema_fields[field_class.index_fieldname].spelling = True

        # Fail more gracefully than relying on the backend to die if no fields
        # are found.
        if len(schema_fields) <= initial_key_count:
            raise SearchBackendError("No fields were found in any search_indexes. Please correct this before attempting to search.")

        return (content_field_name, Schema(**schema_fields))

    def update(self, index, iterable, commit=True):
        if not self.setup_complete:
            self.setup()

        self.index = self.index.refresh()
        writer = AsyncWriter(self.index)

        for obj in iterable:
            try:
                doc = index.full_prepare(obj)
            except SkipDocument:
                self.log.debug(u"Indexing for object `%s` skipped", obj)
            else:
                # Really make sure it's unicode, because Whoosh won't have it any
                # other way.
                for key in doc:
                    doc[key] = self._from_python(doc[key])

                # Document boosts aren't supported in Whoosh 2.5.0+.
                if 'boost' in doc:
                    del doc['boost']

                try:
                    writer.update_document(**doc)
                except Exception as e:
                    if not self.silently_fail:
                        raise

                    # We'll log the object identifier but won't include the actual object
                    # to avoid the possibility of that generating encoding errors while
                    # processing the log message:
                    self.log.error(u"%s while preparing object for update" % e.__class__.__name__,
                                   exc_info=True, extra={"data": {"index": index,
                                                                  "object": get_identifier(obj)}})

        if len(iterable) > 0:
            # For now, commit no matter what, as we run into locking issues otherwise.
            writer.commit()

    def remove(self, obj_or_string, commit=True):
        if not self.setup_complete:
            self.setup()

        self.index = self.index.refresh()
        whoosh_id = get_identifier(obj_or_string)

        try:
            self.index.delete_by_query(q=self.parser.parse(u'%s:"%s"' % (ID, whoosh_id)))
        except Exception as e:
            if not self.silently_fail:
                raise

            self.log.error("Failed to remove document '%s' from Whoosh: %s", whoosh_id, e, exc_info=True)

    def clear(self, models=None, commit=True):
        if not self.setup_complete:
            self.setup()

        self.index = self.index.refresh()

        if models is not None:
            assert isinstance(models, (list, tuple))

        try:
            if models is None:
                self.delete_index()
            else:
                models_to_delete = []

                for model in models:
                    models_to_delete.append(u"%s:%s" % (DJANGO_CT, get_model_ct(model)))

                self.index.delete_by_query(q=self.parser.parse(u" OR ".join(models_to_delete)))
        except Exception as e:
            if not self.silently_fail:
                raise

            if models is not None:
                self.log.error("Failed to clear Whoosh index of models '%s': %s", ','.join(models_to_delete),
                               e, exc_info=True)
            else:
                self.log.error("Failed to clear Whoosh index: %s", e, exc_info=True)

    def delete_index(self):
        # Per the Whoosh mailing list, if wiping out everything from the index,
        # it's much more efficient to simply delete the index files.
        if self.use_file_storage and os.path.exists(self.path):
            shutil.rmtree(self.path)
        elif not self.use_file_storage:
            self.storage.clean()

        # Recreate everything.
        self.setup()

    def optimize(self):
        if not self.setup_complete:
            self.setup()

        self.index = self.index.refresh()
        self.index.optimize()

    def calculate_page(self, start_offset=0, end_offset=None):
        # Prevent against Whoosh throwing an error. Requires an end_offset
        # greater than 0.
        if not end_offset is None and end_offset <= 0:
            end_offset = 1

        # Determine the page.
        page_num = 0

        if end_offset is None:
            end_offset = 1000000

        if start_offset is None:
            start_offset = 0

        page_length = end_offset - start_offset

        if page_length and page_length > 0:
            page_num = int(start_offset / page_length)

        # Increment because Whoosh uses 1-based page numbers.
        page_num += 1
        return page_num, page_length

    @log_query
    def search(self, query_string, sort_by=None, start_offset=0, end_offset=None,
               fields='', highlight=False, facets=None, date_facets=None, query_facets=None,
               narrow_queries=None, spelling_query=None, within=None,
               dwithin=None, distance_point=None, models=None,
               limit_to_registered_models=None, result_class=None, **kwargs):
        if not self.setup_complete:
            self.setup()

        # A zero length query should return no results.
        if len(query_string) == 0:
            return {
                'results': [],
                'hits': 0,
            }

        query_string = force_text(query_string)

        # A one-character query (non-wildcard) gets nabbed by a stopwords
        # filter and should yield zero results.
        if len(query_string) <= 1 and query_string != u'*':
            return {
                'results': [],
                'hits': 0,
            }

        reverse = False

        if sort_by is not None:
            # Determine if we need to reverse the results and if Whoosh can
            # handle what it's being asked to sort by. Reversing is an
            # all-or-nothing action, unfortunately.
            sort_by_list = []
            reverse_counter = 0

            for order_by in sort_by:
                if order_by.startswith('-'):
                    reverse_counter += 1

            if reverse_counter and reverse_counter != len(sort_by):
                raise SearchBackendError("Whoosh requires all order_by fields"
                                         " to use the same sort direction")

            for order_by in sort_by:
                if order_by.startswith('-'):
                    sort_by_list.append(order_by[1:])

                    if len(sort_by_list) == 1:
                        reverse = True
                else:
                    sort_by_list.append(order_by)

                    if len(sort_by_list) == 1:
                        reverse = False

            sort_by = sort_by_list[0]

        if facets is not None:
            warnings.warn("Whoosh does not handle faceting.", Warning, stacklevel=2)

        if date_facets is not None:
            warnings.warn("Whoosh does not handle date faceting.", Warning, stacklevel=2)

        if query_facets is not None:
            warnings.warn("Whoosh does not handle query faceting.", Warning, stacklevel=2)

        narrowed_results = None
        self.index = self.index.refresh()

        if limit_to_registered_models is None:
            limit_to_registered_models = getattr(settings, 'HAYSTACK_LIMIT_TO_REGISTERED_MODELS', True)

        if models and len(models):
            model_choices = sorted(get_model_ct(model) for model in models)
        elif limit_to_registered_models:
            # Using narrow queries, limit the results to only models handled
            # with the current routers.
            model_choices = self.build_models_list()
        else:
            model_choices = []

        if len(model_choices) > 0:
            if narrow_queries is None:
                narrow_queries = set()

            narrow_queries.add(' OR '.join(['%s:%s' % (DJANGO_CT, rm) for rm in model_choices]))

        narrow_searcher = None

        if narrow_queries is not None:
            # Potentially expensive? I don't see another way to do it in Whoosh...
            narrow_searcher = self.index.searcher()

            for nq in narrow_queries:
                recent_narrowed_results = narrow_searcher.search(self.parser.parse(force_text(nq)),
                                                                 limit=None)

                if len(recent_narrowed_results) <= 0:
                    return {
                        'results': [],
                        'hits': 0,
                    }

                if narrowed_results:
                    narrowed_results.filter(recent_narrowed_results)
                else:
                   narrowed_results = recent_narrowed_results

        self.index = self.index.refresh()

        if self.index.doc_count():
            searcher = self.index.searcher()
            parsed_query = self.parser.parse(query_string)

            # In the event of an invalid/stopworded query, recover gracefully.
            if parsed_query is None:
                return {
                    'results': [],
                    'hits': 0,
                }

            page_num, page_length = self.calculate_page(start_offset, end_offset)

            search_kwargs = {
                'pagelen': page_length,
                'sortedby': sort_by,
                'reverse': reverse,
            }

            # Handle the case where the results have been narrowed.
            if narrowed_results is not None:
                search_kwargs['filter'] = narrowed_results

            try:
                raw_page = searcher.search_page(
                    parsed_query,
                    page_num,
                    **search_kwargs
                )
            except ValueError:
                if not self.silently_fail:
                    raise

                return {
                    'results': [],
                    'hits': 0,
                    'spelling_suggestion': None,
                }

            # Because as of Whoosh 2.5.1, it will return the wrong page of
            # results if you request something too high. :(
            if raw_page.pagenum < page_num:
                return {
                    'results': [],
                    'hits': 0,
                    'spelling_suggestion': None,
                }

            results = self._process_results(raw_page, highlight=highlight, query_string=query_string, spelling_query=spelling_query, result_class=result_class)
            searcher.close()

            if hasattr(narrow_searcher, 'close'):
                narrow_searcher.close()

            return results
        else:
            if self.include_spelling:
                if spelling_query:
                    spelling_suggestion = self.create_spelling_suggestion(spelling_query)
                else:
                    spelling_suggestion = self.create_spelling_suggestion(query_string)
            else:
                spelling_suggestion = None

            return {
                'results': [],
                'hits': 0,
                'spelling_suggestion': spelling_suggestion,
            }

    def more_like_this(self, model_instance, additional_query_string=None,
                       start_offset=0, end_offset=None, models=None,
                       limit_to_registered_models=None, result_class=None, **kwargs):
        if not self.setup_complete:
            self.setup()

        # Deferred models will have a different class ("RealClass_Deferred_fieldname")
        # which won't be in our registry:
        model_klass = model_instance._meta.concrete_model

        field_name = self.content_field_name
        narrow_queries = set()
        narrowed_results = None
        self.index = self.index.refresh()

        if limit_to_registered_models is None:
            limit_to_registered_models = getattr(settings, 'HAYSTACK_LIMIT_TO_REGISTERED_MODELS', True)

        if models and len(models):
            model_choices = sorted(get_model_ct(model) for model in models)
        elif limit_to_registered_models:
            # Using narrow queries, limit the results to only models handled
            # with the current routers.
            model_choices = self.build_models_list()
        else:
            model_choices = []

        if len(model_choices) > 0:
            if narrow_queries is None:
                narrow_queries = set()

            narrow_queries.add(' OR '.join(['%s:%s' % (DJANGO_CT, rm) for rm in model_choices]))

        if additional_query_string and additional_query_string != '*':
            narrow_queries.add(additional_query_string)

        narrow_searcher = None

        if narrow_queries is not None:
            # Potentially expensive? I don't see another way to do it in Whoosh...
            narrow_searcher = self.index.searcher()

            for nq in narrow_queries:
                recent_narrowed_results = narrow_searcher.search(self.parser.parse(force_text(nq)),
                                                                 limit=None)

                if len(recent_narrowed_results) <= 0:
                    return {
                        'results': [],
                        'hits': 0,
                    }

                if narrowed_results:
                    narrowed_results.filter(recent_narrowed_results)
                else:
                   narrowed_results = recent_narrowed_results

        page_num, page_length = self.calculate_page(start_offset, end_offset)

        self.index = self.index.refresh()
        raw_results = EmptyResults()

        if self.index.doc_count():
            query = "%s:%s" % (ID, get_identifier(model_instance))
            searcher = self.index.searcher()
            parsed_query = self.parser.parse(query)
            results = searcher.search(parsed_query)

            if len(results):
                raw_results = results[0].more_like_this(field_name, top=end_offset)

            # Handle the case where the results have been narrowed.
            if narrowed_results is not None and hasattr(raw_results, 'filter'):
                raw_results.filter(narrowed_results)

        try:
            raw_page = ResultsPage(raw_results, page_num, page_length)
        except ValueError:
            if not self.silently_fail:
                raise

            return {
                'results': [],
                'hits': 0,
                'spelling_suggestion': None,
            }

        # Because as of Whoosh 2.5.1, it will return the wrong page of
        # results if you request something too high. :(
        if raw_page.pagenum < page_num:
            return {
                'results': [],
                'hits': 0,
                'spelling_suggestion': None,
            }

        results = self._process_results(raw_page, result_class=result_class)
        searcher.close()

        if hasattr(narrow_searcher, 'close'):
            narrow_searcher.close()

        return results

    def _process_results(self, raw_page, highlight=False, query_string='', spelling_query=None, result_class=None):
        from haystack import connections
        results = []

        # It's important to grab the hits first before slicing. Otherwise, this
        # can cause pagination failures.
        hits = len(raw_page)

        if result_class is None:
            result_class = SearchResult

        facets = {}
        spelling_suggestion = None
        unified_index = connections[self.connection_alias].get_unified_index()
        indexed_models = unified_index.get_indexed_models()

        for doc_offset, raw_result in enumerate(raw_page):
            score = raw_page.score(doc_offset) or 0
            app_label, model_name = raw_result[DJANGO_CT].split('.')
            additional_fields = {}
            model = haystack_get_model(app_label, model_name)

            if model and model in indexed_models:
                for key, value in raw_result.items():
                    index = unified_index.get_index(model)
                    string_key = str(key)

                    if string_key in index.fields and hasattr(index.fields[string_key], 'convert'):
                        # Special-cased due to the nature of KEYWORD fields.
                        if index.fields[string_key].is_multivalued:
                            if value is None or len(value) is 0:
                                additional_fields[string_key] = []
                            else:
                                additional_fields[string_key] = value.split(',')
                        else:
                            additional_fields[string_key] = index.fields[string_key].convert(value)
                    else:
                        additional_fields[string_key] = self._to_python(value)

                del(additional_fields[DJANGO_CT])
                del(additional_fields[DJANGO_ID])

                if highlight:
                    sa = StemmingAnalyzer()
                    formatter = WhooshHtmlFormatter('em')
                    terms = [token.text for token in sa(query_string)]

                    whoosh_result = whoosh_highlight(
                        additional_fields.get(self.content_field_name),
                        terms,
                        sa,
                        ContextFragmenter(),
                        formatter
                    )
                    additional_fields['highlighted'] = {
                        self.content_field_name: [whoosh_result],
                    }

                result = result_class(app_label, model_name, raw_result[DJANGO_ID], score, **additional_fields)
                results.append(result)
            else:
                hits -= 1

        if self.include_spelling:
            if spelling_query:
                spelling_suggestion = self.create_spelling_suggestion(spelling_query)
            else:
                spelling_suggestion = self.create_spelling_suggestion(query_string)

        return {
            'results': results,
            'hits': hits,
            'facets': facets,
            'spelling_suggestion': spelling_suggestion,
        }

    def create_spelling_suggestion(self, query_string):
        spelling_suggestion = None
        reader = self.index.reader()
        corrector = reader.corrector(self.content_field_name)
        cleaned_query = force_text(query_string)

        if not query_string:
            return spelling_suggestion

        # Clean the string.
        for rev_word in self.RESERVED_WORDS:
            cleaned_query = cleaned_query.replace(rev_word, '')

        for rev_char in self.RESERVED_CHARACTERS:
            cleaned_query = cleaned_query.replace(rev_char, '')

        # Break it down.
        query_words = cleaned_query.split()
        suggested_words = []

        for word in query_words:
            suggestions = corrector.suggest(word, limit=1)

            if len(suggestions) > 0:
                suggested_words.append(suggestions[0])

        spelling_suggestion = ' '.join(suggested_words)
        return spelling_suggestion

    def _from_python(self, value):
        """
        Converts Python values to a string for Whoosh.

        Code courtesy of pysolr.
        """
        if hasattr(value, 'strftime'):
            if not hasattr(value, 'hour'):
                value = datetime(value.year, value.month, value.day, 0, 0, 0)
        elif isinstance(value, bool):
            if value:
                value = 'true'
            else:
                value = 'false'
        elif isinstance(value, (list, tuple)):
            value = u','.join([force_text(v) for v in value])
        elif isinstance(value, (six.integer_types, float)):
            # Leave it alone.
            pass
        else:
            value = force_text(value)
        return value

    def _to_python(self, value):
        """
        Converts values from Whoosh to native Python values.

        A port of the same method in pysolr, as they deal with data the same way.
        """
        if value == 'true':
            return True
        elif value == 'false':
            return False

        if value and isinstance(value, six.string_types):
            possible_datetime = DATETIME_REGEX.search(value)

            if possible_datetime:
                date_values = possible_datetime.groupdict()

                for dk, dv in date_values.items():
                    date_values[dk] = int(dv)

                return datetime(date_values['year'], date_values['month'], date_values['day'], date_values['hour'], date_values['minute'], date_values['second'])

        try:
            # Attempt to use json to load the values.
            converted_value = json.loads(value)

            # Try to handle most built-in types.
            if isinstance(converted_value, (list, tuple, set, dict, six.integer_types, float, complex)):
                return converted_value
        except:
            # If it fails (SyntaxError or its ilk) or we don't trust it,
            # continue on.
            pass

        return value


class WhooshSearchQuery(BaseSearchQuery):
    def _convert_datetime(self, date):
        if hasattr(date, 'hour'):
            return force_text(date.strftime('%Y%m%d%H%M%S'))
        else:
            return force_text(date.strftime('%Y%m%d000000'))

    def clean(self, query_fragment):
        """
        Provides a mechanism for sanitizing user input before presenting the
        value to the backend.

        Whoosh 1.X differs here in that you can no longer use a backslash
        to escape reserved characters. Instead, the whole word should be
        quoted.
        """
        words = query_fragment.split()
        cleaned_words = []

        for word in words:
            if word in self.backend.RESERVED_WORDS:
                word = word.replace(word, word.lower())

            for char in self.backend.RESERVED_CHARACTERS:
                if char in word:
                    word = "'%s'" % word
                    break

            cleaned_words.append(word)

        return ' '.join(cleaned_words)

    def build_query_fragment(self, field, filter_type, value):
        from haystack import connections
        query_frag = ''
        is_datetime = False

        if not hasattr(value, 'input_type_name'):
            # Handle when we've got a ``ValuesListQuerySet``...
            if hasattr(value, 'values_list'):
                value = list(value)

            if hasattr(value, 'strftime'):
                is_datetime = True

            if isinstance(value, six.string_types) and value != ' ':
                # It's not an ``InputType``. Assume ``Clean``.
                value = Clean(value)
            else:
                value = PythonData(value)

        # Prepare the query using the InputType.
        prepared_value = value.prepare(self)

        if not isinstance(prepared_value, (set, list, tuple)):
            # Then convert whatever we get back to what pysolr wants if needed.
            prepared_value = self.backend._from_python(prepared_value)

        # 'content' is a special reserved word, much like 'pk' in
        # Django's ORM layer. It indicates 'no special field'.
        if field == 'content':
            index_fieldname = ''
        else:
            index_fieldname = u'%s:' % connections[self._using].get_unified_index().get_index_fieldname(field)

        filter_types = {
            'content': '%s',
            'contains': '*%s*',
            'endswith': "*%s",
            'startswith': "%s*",
            'exact': '%s',
            'gt': "{%s to}",
            'gte': "[%s to]",
            'lt': "{to %s}",
            'lte': "[to %s]",
            'fuzzy': u'%s~',
        }

        if value.post_process is False:
            query_frag = prepared_value
        else:
            if filter_type in ['content', 'contains', 'startswith', 'endswith', 'fuzzy']:
                if value.input_type_name == 'exact':
                    query_frag = prepared_value
                else:
                    # Iterate over terms & incorportate the converted form of each into the query.
                    terms = []

                    if isinstance(prepared_value, six.string_types):
                        possible_values = prepared_value.split(' ')
                    else:
                        if is_datetime is True:
                            prepared_value = self._convert_datetime(prepared_value)

                        possible_values = [prepared_value]

                    for possible_value in possible_values:
                        terms.append(filter_types[filter_type] % self.backend._from_python(possible_value))

                    if len(terms) == 1:
                        query_frag = terms[0]
                    else:
                        query_frag = u"(%s)" % " AND ".join(terms)
            elif filter_type == 'in':
                in_options = []

                for possible_value in prepared_value:
                    is_datetime = False

                    if hasattr(possible_value, 'strftime'):
                        is_datetime = True

                    pv = self.backend._from_python(possible_value)

                    if is_datetime is True:
                        pv = self._convert_datetime(pv)

                    if isinstance(pv, six.string_types) and not is_datetime:
                        in_options.append('"%s"' % pv)
                    else:
                        in_options.append('%s' % pv)

                query_frag = "(%s)" % " OR ".join(in_options)
            elif filter_type == 'range':
                start = self.backend._from_python(prepared_value[0])
                end = self.backend._from_python(prepared_value[1])

                if hasattr(prepared_value[0], 'strftime'):
                    start = self._convert_datetime(start)

                if hasattr(prepared_value[1], 'strftime'):
                    end = self._convert_datetime(end)

                query_frag = u"[%s to %s]" % (start, end)
            elif filter_type == 'exact':
                if value.input_type_name == 'exact':
                    query_frag = prepared_value
                else:
                    prepared_value = Exact(prepared_value).prepare(self)
                    query_frag = filter_types[filter_type] % prepared_value
            else:
                if is_datetime is True:
                    prepared_value = self._convert_datetime(prepared_value)

                query_frag = filter_types[filter_type] % prepared_value

        if len(query_frag) and not isinstance(value, Raw):
            if not query_frag.startswith('(') and not query_frag.endswith(')'):
                query_frag = "(%s)" % query_frag

        return u"%s%s" % (index_fieldname, query_frag)


        # if not filter_type in ('in', 'range'):
        #     # 'in' is a bit of a special case, as we don't want to
        #     # convert a valid list/tuple to string. Defer handling it
        #     # until later...
        #     value = self.backend._from_python(value)


class WhooshEngine(BaseEngine):
    backend = WhooshSearchBackend
    query = WhooshSearchQuery

5. 创建索引

如果你想针对某个 app 例如 blog 做全文检索,则必须在 blog 的目录下面建立 search_indexes.py 文件,文件名不能修改。内容如下:

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
__author__ = 'yinzhuoqun'

# import datetime
from haystack import indexes
from blog.models import Article


# 类名必须为需要检索的 Model_name + Index,这里需要检索Article,所以创建ArticleIndex
class ArticleIndex(indexes.SearchIndex, indexes.Indexable):
    text = indexes.CharField(document=True, use_template=True)  # 创建一个text字段
    author = indexes.CharField(model_attr='author')  # 创建一个author字段
    pub_date = indexes.DateTimeField(model_attr='time_created')  # 创建一个pub_date字段

    def get_model(self):  # 重载 get_model方法,必须要有!
        return Article

    def index_queryset(self, using=None):  # 重载index_..函数
        """Used when the entire index for model is updated."""
        return self.get_model().objects.filter(show_status=True).order_by('-pub_date')

每个索引里面必须有且只能有一个字段为 document=True,这代表 haystack 和搜索引擎将使用此字段的内容作为索引进行检索(primary field)。其他的字段只是附属的属性,方便调用,并不作为检索数据。

注意:如果使用一个字段设置了 document=True,则一般约定此字段名为text,这是在 SearchIndex类里面一贯的命名,以防止后台混乱,当然名字你也可以随便改,不过不建议改。

并且,haystack 提供了 use_template=True 在 text字段,这样就允许我们使用数据模板去建立搜索引擎索引的文件,使用方便(官方推荐,当然还有其他复杂的建立索引文件的方式,目前我还不知道),数据模板的路径为 youapp/templates/search/indexes/youapp/article_text.txt,例如本例子为 blog/templates/search/indexes/blog/article_text.txt 文件名必须为要索引的 类名_text.txt, 其内容为:

{{ object.title }}
{{ object.content }}
{{ object.author.username }}

这个数据模板的作用是对 Article.title, Article.content, Article.author( ForeignKey ) 这几个字段建立索引,当检索的时候会对这三个字段做全文检索匹配。

6. 在 app 下的 urls.py  配置中添加 SearchView,并配置模板

#!/usr/bin/env python3
# -*- coding: utf-8 -*-


from django.conf.urls import url, include
from blog import views
from haystack.views import SearchView

urlpatterns = [
    url(r'^$', views.IndexView.as_view(), name='index'),
    url(r'^search/', views.MySeachView(), name='search'),   
]

# views.py

class MySeachView(SearchView):
    template = 'search/search.html'

    def extra_context(self):  # 重载extra_context来添加额外的context内容
        context = super(MySeachView, self).extra_context()
        # context['nodes'] = Node.objects.filter().order_by("-id") 
        return context

SearchView()视图函数默认使用的 html 模板为 当前app目录下,路径为 myapp/templates/search/search.html
所以需要在 blog/templates/search/下添加 search.html文件,内容为:


{% block article_list %}
    <div class="am-u-md-8 am-u-sm-12">
{#        {% if page %}#}
{#            <h2>搜索&nbsp;<b>{% myhighlight query with query css_class "myhighlight" html_tag "span" %}</b>&nbsp;结果如下:#}
{#            </h2>#}
{#        {% endif %}#}
        {% for article in page %}
            <article class="am-g blog-entry-article">
                <div class="am-u-lg-6 am-u-md-12 am-u-sm-12 blog-entry-img">
                    <a href="{% url 'blog:detail' article.object.id %}">
                        <img src="{{ article.object.get_contentimg_url }}"
                             onerror="this.src='http://photo.python3.top/f161.jpg'"
                             alt="" class="am-u-sm-12">
                    </a>
                </div>
                <div class="am-u-lg-6 am-u-md-12 am-u-sm-12 blog-entry-text">
                    <span><a href="{% url "blog:node" article.object.node %}" class="blog-color">{{ article.object.node }} &nbsp;</a></span>
                    <span class="am-icon-user"> {{ article.object.author }} &nbsp;</span>
                    <span class="am-icon-clock-o">&nbsp;{{ article.object.time_created | date:"Y/n/j" }}&nbsp;</span>
                    <span class="am-icon-eye">&nbsp;{{ article.object.num_views|add:"20" }}&nbsp;</span>
                    {#                    <h1><a href="{% url 'blog:detail' article.object.id %}">{{ article.object.title | capfirst }}</a>#}
                    <h1>
                        <a href="{% url 'blog:detail' article.object.id %}">{% myhighlight article.object.title with query css_class "myhighlight" html_tag "span" %}</a>
                    </h1>
                    {#                    {% myhighlight article.object.content with query css_class "myhighlight" html_tag "span" max_length 100 %}#}
                    {#                    <a href="{% url 'blog:detail' article.object.id %}">#}

                    {% if "img" and "src=" in article.content|truncatechars_html:30 %}
                        {% myhighlight article.object.content with query css_class "myhighlight" html_tag "span" max_length 100 %}
                        {#                                                                {{ article.content | truncatechars_html:30 }}#}
                    {% else %}
                        {% myhighlight article.object.content with query css_class "myhighlight" html_tag "span" max_length 100 %}
                        {#                            {{ article.content | truncatechars_html:30 | safe }}#}
                    {% endif %}
                    {#                    </a>#}

                    <p><a href="" class="blog-continue">continue reading</a></p>
                </div>
            </article>
        {% empty %}
            <h1>Sorry,未找到与 {% myhighlight query with query css_class "myhighlight" html_tag "span" %} 相关的文章</h1>
        {% endfor %}

        <ul data-am-widget="pagination" class="am-pagination am-pagination-select">
            {% if page.has_previous %}
                <li class="am-pagination-prev"><a href="?q={{ query }}&amp;page={{ page.previous_page_number }}">&laquo;
                    Prev</a></li>
            {% endif %}

            {% if page.paginator.num_pages != 1 %}
                <li class="am-pagination-select">
                    <select id="page-select" onchange="window.location=this.value;" autocomplete="off">
                        {% for page_num in page.paginator.page_range %}
                            {% if page.number == page_num %}
                                <option value="?q={{ query }}&amp;page={{ page_num }}" class="" selected="selected">
                                    {{ page_num }}/{{ page.paginator.num_pages }}
                                </option>
                            {% else %}
                                <option value="?q={{ query }}&amp;page={{ page_num }}" class="">
                                {{ page_num }}/{{ page.paginator.num_pages }}
                            {% endif %}
                        {% endfor %}
                    </select>
                </li>
            {% endif %}

            {% if page.has_next %}
                <li class="am-pagination-next"><a href="?q={{ query }}&amp;page={{ page.next_page_number }}">Next
                    &raquo;</a></li>
            {% endif %}

        </ul>
    </div>
{% endblock %}

7. 最后一步,重建索引文件

# 项目路径 >python manage.py
[haystack]
    build_solr_schema
    clear_index
    haystack_info
    rebuild_index
    update_index

使用 python manage.py rebuild_index 或者使用 update_index命令。

三. 效果图

搜索 django :(关键词高亮)

 

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