Files
consumocuidado-server/products/utils.py
2021-02-19 10:31:34 +00:00

141 lines
4.1 KiB
Python

import logging
from django.db.models import Q
from django.contrib.postgres.search import SearchQuery, SearchRank, SearchVector, TrigramSimilarity
from products.models import Product
def extract_search_filters(result_set):
"""
Returned object should look something like:
{
"singles": [], # non tree tags
"entry_1": [ 'tag1', 'tag2' ],
"entry_2": [ 'tag1', 'tag2' ],
}
"""
filter_dict = {
'singles': set(),
}
for item in result_set:
try:
# extract tags
tags = item.tags.all()
for tag in tags:
if len(tag.name.split('/')) == 1:
filter_dict['singles'].add(tag.name)
else:
# set penultimate tag as header
chunks = tag.name.split('/')
header = chunks[-2]
name = chunks[-1]
# check if
entry = filter_dict.get(header)
if entry is None:
filter_dict[header] = set()
filter_dict[header].add(name)
# extract attributes
attributes = item.attributes.all()
for tag in attributes:
if len(tag.name.split('/')) == 1:
filter_dict['singles'].add(tag.name)
else:
# set penultimate tag as header
chunks = tag.name.split('/')
header = chunks[-2]
name = chunks[-1]
# check if
entry = filter_dict.get(header)
if entry is None:
filter_dict[header] = set()
filter_dict[header].add(name)
except Exception as e:
logging.error(f'Extacting filters for {item}')
return filter_dict
def find_related_products_v1(keyword):
"""
Classical approach to the search
Using Q objects
"""
# search in tags
tags = Product.tags.tag_model.objects.filter(name__icontains=keyword)
# search in category
categories = Product.category.tag_model.objects.filter(name__icontains=keyword)
# search in attributes
attributes = Product.attributes.tag_model.objects.filter(name__icontains=keyword)
# unified tag search
products_qs = Product.objects.filter(
Q(name__icontains=keyword)|
Q(description__icontains=keyword)|
Q(tags__in=tags)|
Q(category__in=categories)|
Q(attributes__in=attributes)
)
return products_qs
def find_related_products_v5(keyword):
"""
Single query solution, using Q objects
"""
products_qs = Product.objects.filter(
Q(name__icontains=keyword)|
Q(description__icontains=keyword)|
Q(tags__label__icontains=keyword)|
Q(category__name__icontains=keyword)|
Q(attributes__label__icontains=keyword)
)
return products_qs
def find_related_products_v2(keyword):
"""
More advanced: using search vectors
"""
fields=('name', 'description', 'tags__label', 'attributes__label', 'category__name')
vector = SearchVector(*fields)
products_qs = Product.objects.annotate(
search=vector
).filter(search=keyword)
return products_qs
def find_related_products_v3(keyword):
"""
Ranked product search
SearchVectors for the fields
SearchQuery for the value
SearchRank for relevancy scoring and ranking
PROBLEM: returns unrelated instances
"""
# TODO: figure out why it includes unrelated instances
fields=('name', 'description', 'tags__label', 'attributes__label', 'category__name')
vector = SearchVector(*fields)
query = SearchQuery(keyword)
products_qs = Product.objects.annotate(
rank=SearchRank(vector, query)
).order_by('-rank')
return products_qs
def find_related_products_v4(keyword):
"""
Using trigrams
"""
# fields=('name', 'description', 'tags__label', 'attributes__label', 'category__name')
products_qs = Product.objects.annotate(
similarity=TrigramSimilarity('name', keyword),
).order_by('-similarity')
return products_qs