src/search/utils.py

   1 from django.db.models import Func
   2 from django.contrib.postgres.search import SearchVector, SearchQuery, SearchQueryField, SearchHeadline as SH
   3
   4
   5
   6 class UnaccentTSVector(Func):
   7     function = 'UNACCENT'
   8     template = '%(function)s(%(expressions)s::text)::tsvector'
   9
  10
  11 class Unaccent(Func):
  12     function = 'UNACCENT'
  13
  14
  15 class ConcatTSVector(Func):
  16     function = 'CONCAT'
  17     template = '%(function)s(%(expressions)s)::tsvector'
  18
  19
  20 class UnaccentTSQuery(Func):
  21     function = 'UNACCENT'
  22     template = '%(function)s(%(expressions)s::text)::tsquery'
  23     output_field = SearchQueryField()
  24
  25
  26 class TSV(Func):
  27     function='to_tsvector'
  28     template = '''unaccent(
  29       %(function)s('polish', %(expressions)s)::text)::tsvector ||
  30      to_tsvector(
  31        'polish_simple',
  32        unaccent(%(expressions)s)
  33      )'''
  34
  35
  36 def build_search_vector(*fields):
  37     return TSV(*fields)
  38
  39
  40 def build_search_query(*fields, **kwargs):
  41     return UnaccentTSQuery(SearchQuery(*fields, **kwargs))
  42
  43
  44
  45 class SearchHeadline(SH):
  46
  47     def __init__(
  48         self,
  49         expression,
  50         query,
  51         *,
  52         config=None,
  53         start_sel=None,
  54         stop_sel=None,
  55         max_words=None,
  56         min_words=None,
  57         short_word=None,
  58         highlight_all=None,
  59         max_fragments=None,
  60         fragment_delimiter=None,
  61     ):
  62         options = {
  63             "StartSel": start_sel,
  64             "StopSel": stop_sel,
  65             "MaxWords": max_words,
  66             "MinWords": min_words,
  67             "ShortWord": short_word,
  68             "HighlightAll": highlight_all,
  69             "MaxFragments": max_fragments,
  70             "FragmentDelimiter": fragment_delimiter,
  71         }
  72         self.options = {
  73             option: value for option, value in options.items() if value is not None
  74         }
  75         expressions = (expression, query)
  76         if config is not None:
  77             config = SearchConfig.from_parameter(config)
  78             expressions = (config,) + expressions
  79         Func.__init__(self, *expressions)