Files
mayan-edms/mayan/apps/dynamic_search/classes.py
2018-10-06 22:20:13 -04:00

263 lines
8.2 KiB
Python

from __future__ import absolute_import, unicode_literals
import datetime
import logging
from django.apps import apps
from django.db.models import Q
from django.utils.encoding import force_text
from django.utils.module_loading import import_string
from django.utils.translation import ugettext as _
from .settings import setting_limit
logger = logging.getLogger(__name__)
QUERY_OPERATION_AND = 1
QUERY_OPERATION_OR = 2
TERM_OPERATION_AND = 'AND'
TERM_OPERATION_OR = 'OR'
TERM_OPERATIONS = [TERM_OPERATION_AND, TERM_OPERATION_OR]
class SearchModel(object):
_registry = {}
@classmethod
def all(cls):
return list(cls._registry.values())
@classmethod
def as_choices(cls):
return cls._registry
@classmethod
def get(cls, full_name):
try:
result = cls._registry[full_name]
except KeyError:
raise KeyError(_('No search model matching the query'))
if not hasattr(result, 'serializer'):
result.serializer = import_string(result.serializer_string)
return result
@staticmethod
def get_terms(text):
"""
Takes a text string and returns a list of dictionaries.
Each dictionary has two key "negated" and "string"
String 'a "b c" d "e" \'f g\' h -i -"j k" l -\'m n\' o OR p'
Results in:
[
{'negated': False, 'string': 'a'}, {'negated': False, 'string': 'b c'},
{'negated': False, 'string': 'd'}, {'negated': False, 'string': 'e'},
{'negated': False, 'string': 'f g'}, {'negated': False, 'string': 'h'},
{'negated': True, 'string': 'i'}, {'negated': True, 'string': 'j k'},
{'negated': False, 'string': 'l'}, {'negated': True, 'string': 'm n'},
{'negated': False, 'string': 'o'}, {'negated': False, 'string': 'OR'},
{'negated': False, 'string': 'p'}
]
"""
QUOTES = ['"', '\'']
NEGATION_CHARACTER = '-'
SPACE_CHARACTER = ' '
inside_quotes = False
negated = False
term_letters = []
terms = []
for letter in text:
if not inside_quotes and letter == NEGATION_CHARACTER:
negated = True
else:
if letter in QUOTES:
if inside_quotes:
if term_letters:
terms.append(
{
'meta': False,
'negated': negated,
'string': ''.join(term_letters)
}
)
negated = False
term_letters = []
inside_quotes = not inside_quotes
else:
if not inside_quotes and letter == SPACE_CHARACTER:
if term_letters:
term_string = ''.join(term_letters)
if term_string in TERM_OPERATIONS:
meta = True
else:
meta = False
terms.append(
{
'meta': meta,
'negated': negated,
'string': term_string
}
)
negated = False
term_letters = []
else:
term_letters.append(letter)
if term_letters:
terms.append(
{
'meta': False,
'negated': negated,
'string': ''.join(term_letters)
}
)
return terms
def __init__(self, app_label, model_name, serializer_string, label=None, permission=None):
self.app_label = app_label
self.model_name = model_name
self.search_fields = []
self._model = None # Lazy
self._label = label
self.serializer_string = serializer_string
self.permission = permission
self.__class__._registry[self.get_full_name()] = self
@property
def label(self):
if not self._label:
self._label = self.model._meta.verbose_name
return self._label
@property
def model(self):
if not self._model:
self._model = apps.get_model(self.app_label, self.model_name)
return self._model
@property
def pk(self):
return self.get_full_name()
def add_model_field(self, *args, **kwargs):
"""
Add a search field that directly belongs to the parent SearchModel
"""
search_field = SearchField(self, *args, **kwargs)
self.search_fields.append(search_field)
def get_all_search_fields(self):
return self.search_fields
def get_full_name(self):
return '%s.%s' % (self.app_label, self.model_name)
def get_fields_simple_list(self):
"""
Returns a list of the fields for the SearchModel
"""
result = []
for search_field in self.get_all_search_fields():
result.append((search_field.get_full_name(), search_field.label))
return result
def get_search_field(self, full_name):
try:
return self.search_fields[full_name]
except KeyError:
raise KeyError('No search field named: %s' % full_name)
def search(self, query_string, user, global_and_search=False):
AccessControlList = apps.get_model(
app_label='acls', model_name='AccessControlList'
)
elapsed_time = 0
start_time = datetime.datetime.now()
result = None
for search_field in self.get_all_search_fields():
terms = self.get_terms(
query_string.get(
search_field.field, query_string.get('q', '')
).strip()
)
field_query = search_field.get_query(terms=terms)
if field_query:
if result is None:
result = field_query
else:
if global_and_search:
result = result & field_query
else:
result = result | field_query
elapsed_time = force_text(
datetime.datetime.now() - start_time
).split(':')[2]
logger.debug('elapsed_time: %s', elapsed_time)
pk_list = set(self.model.objects.filter(result or Q()).values_list('pk', flat=True)[:setting_limit.value])
queryset = self.model.objects.filter(pk__in=pk_list)
if self.permission:
queryset = AccessControlList.objects.filter_by_access(
permission=self.permission, user=user, queryset=queryset
)
return queryset, elapsed_time
class SearchField(object):
"""
Search for terms in fields that directly belong to the parent SearchModel
"""
def __init__(self, search_model, field, label):
self.search_model = search_model
self.field = field
self.label = label
def get_full_name(self):
return self.field
def get_model(self):
return self.search_model.model
def get_query(self, terms):
query_operation = QUERY_OPERATION_AND
result = None
for term in terms:
if term['meta']:
# It is a meta term, modifies the query operation
# and is not searched
if term['string'] == TERM_OPERATION_OR:
query_operation = QUERY_OPERATION_OR
else:
q_object = Q(
**{'%s__%s' % (self.field, 'icontains'): term['string']}
)
if term['negated']:
q_object = ~q_object
if result is None:
result = q_object
else:
if query_operation == QUERY_OPERATION_AND:
result = result & q_object
else:
result = result | q_object
return result