Files
mayan-edms/mayan/apps/dynamic_search/classes.py
2018-04-01 20:25:05 -04:00

335 lines
11 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__)
class SearchModel(object):
_registry = {}
@classmethod
def all(cls):
return 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 = []
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:
terms.append(
{
'meta': False,
'negated': negated,
'string': ''.join(term)
}
)
negated = False
term = []
inside_quotes = not inside_quotes
else:
if not inside_quotes and letter == SPACE_CHARACTER:
if term:
if term == ['O', 'R']:
meta = True
else:
meta = False
terms.append(
{
'meta': meta,
'negated': negated,
'string': ''.join(term)
}
)
negated = False
term = []
else:
term.append(letter)
if term:
terms.append(
{
'meta': False,
'negated': negated,
'string': ''.join(term)
}
)
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 assemble_query(self, terms, search_fields):
"""
Returns a query, that is a combination of Q objects. That combination
aims to search keywords within a model by testing the given search
fields.
"""
queries = []
for term in terms:
query = None
if term['string'] != 'OR':
for field in search_fields:
q = Q(**{'%s__%s' % (field, 'icontains'): term['string']})
if term['negated']:
q = ~q
if query is None:
query = q
else:
query = query | q
queries.append(query)
return queries
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_set = set()
search_dict = {}
if 'q' in query_string:
# Simple search
for search_field in self.get_all_search_fields():
search_dict.setdefault(search_field.get_model(), {
'searches': [],
'label': search_field.label,
'return_value': search_field.return_value
})
search_dict[search_field.get_model()]['searches'].append(
{
'field_name': [search_field.field],
'terms': SearchModel.get_terms(
query_string.get('q', '').strip()
)
}
)
else:
for search_field in self.get_all_search_fields():
if search_field.field in query_string and query_string[search_field.field]:
search_dict.setdefault(search_field.get_model(), {
'searches': [],
'label': search_field.label,
'return_value': search_field.return_value
})
search_dict[search_field.get_model()]['searches'].append(
{
'field_name': [search_field.field],
'terms': SearchModel.get_terms(
query_string[search_field.field]
)
}
)
for model, data in search_dict.items():
logger.debug('model: %s', model)
# Initialize per model result set
model_result_set = set()
for query_entry in data['searches']:
# Fashion a list of queries for a field for each term
field_query_list = self.assemble_query(
query_entry['terms'], query_entry['field_name']
)
logger.debug('field_query_list: %s', field_query_list)
# Initialize per field result set
field_result_set = set()
# Get results per search field
intersection = True
for query in field_query_list:
logger.debug('query: %s', query)
if query:
term_query_result_set = set(
model.objects.filter(query).values_list(
data['return_value'], flat=True
)
)
# Convert the QuerySet to a Python set and perform the
# AND operation on the program and not as a query.
# This operation ANDs all the field term results
# belonging to a single model, making sure to only include
# results in the final field result variable if all the
# terms are found in a single field.
if not field_result_set:
field_result_set = term_query_result_set
else:
if intersection:
field_result_set &= term_query_result_set
else:
field_result_set |= term_query_result_set
logger.debug(
'term_query_result_set: %s', len(term_query_result_set)
)
logger.debug('field_result_set: %s', len(field_result_set))
intersection = True
else:
intersection = False
if global_and_search:
if not model_result_set:
model_result_set = field_result_set
else:
model_result_set &= field_result_set
else:
model_result_set |= field_result_set
result_set = result_set | model_result_set
elapsed_time = force_text(
datetime.datetime.now() - start_time
).split(':')[2]
logger.debug('elapsed_time: %s', elapsed_time)
queryset = self.model.objects.filter(
pk__in=list(result_set)[:setting_limit.value]
)
if self.permission:
queryset = AccessControlList.objects.filter_by_access(
permission=self.permission, user=user, queryset=queryset
)
return queryset, elapsed_time
# SearchField classes
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
self.return_value = 'pk'
def get_full_name(self):
return self.field
def get_model(self):
return self.search_model.model