import csv
import logging
import os
import pprint
import re
from collections import Counter, OrderedDict
from itertools import zip_longest
from django import template
from django.conf import settings
from django.contrib.staticfiles import finders
from django.core.management.base import BaseCommand
logger = logging.getLogger(__name__)
RE_PATTERNS = {
'view_html': '[\'\"](.*\.html)',
'html_html': '{% (?:extends|include) [\'\"]?(.*\.html)',
'html_style': '{% static [\'\"]?(.*\.css)',
'css_media': (
'^\s*\@media([^{]+)\{\s*([\s\S]*?})\s*}'
),
'css_selector': (
'^\s*([.#\[:_A-Za-z][^{]*)'
'{([\s\S]*?)}'
),
'html_class': 'class=[\'\"]([a-zA-Z0-9-_\s]*)',
'html_id': 'id=[\'\"]([a-zA-Z0-9-_]*)'
}
class Command(BaseCommand):
help = 'Finds and fixes unused css styles in the templates'
requires_system_checks = False
def add_arguments(self, parser):
# positional arguments
parser.add_argument(
'apps', nargs='+', type=str,
help='name of the apps to be optimized'
)
# Named (optional) arguments
parser.add_argument(
'--together',
action='store_true',
help='optimize the apps together'
)
parser.add_argument(
'--css',
action='store_true',
help='optimize only css rules in each file'
)
def handle(self, *args, **options):
apps_list = options['apps']
for app in apps_list:
if options['css']:
self.optimize_css(app)
# else:
# optimize_all(app)
def optimize_css(self, app_name):
# get html and css files used in the app
files = get_files(app_name)
# get_selectors_from_css
css_selectors = get_selectors_css(files['style'])
# get_selectors_from_html
html_selectors = get_selectors_html(files['html'])
# get duplication of css rules from css files
css_dup_report = get_css_duplication(css_selectors)
def get_files(app_name):
# the view file for the app
app_view = os.path.join(settings.PROJECT_DIR, app_name, 'views.py')
# get template files called from the view
all_html_list = file_match_pattern(app_view, 'view_html')
# list of unique template files
uniq_html_list = list(OrderedDict.fromkeys(all_html_list).keys())
# list of stylesheets
all_style_list = []
file_patterns = ['html_html', 'html_style']
# get html and css files called from within templates
i = 0
while i < len(uniq_html_list):
template_name = uniq_html_list[i]
try:
# a dict containing 'html' and 'css' files
temp_files = templates_match_pattern(
template_name, file_patterns
)
except template.exceptions.TemplateDoesNotExist as e:
print("template file not found: ", str(e))
all_html_list = [
h for h in all_html_list if h != template_name
]
del uniq_html_list[i]
else:
all_html_list.extend(temp_files[0])
uniq_html_list = list(
OrderedDict.fromkeys(all_html_list).keys()
)
all_style_list.extend(temp_files[1])
i += 1
# counter dict for the html files called from view
result = {
'html': Counter(all_html_list),
'style': Counter(all_style_list)
}
print(result)
return result
def get_selectors_css(files):
selectors = {}
media_selectors = {}
for file in files:
if any(vendor in file for vendor in ['bootstrap', 'font-awesome']):
continue
result = finders.find(file)
if result:
with open(result) as f:
data = f.read()
media_selectors[file] = string_match_pattern(
data, 'css_media'
)
new_data = string_replace_pattern(
data, 'css_media'
)
selectors[file] = {
'default': string_match_pattern(
new_data, 'css_selector'
)
}
# pp = pprint.PrettyPrinter(compact=False, width=120)
# pp.pprint(media_selectors)
for file, match_list in media_selectors.items():
for match in match_list:
query = match[0]
block_text = ' '.join(match[1].split())
results = string_match_pattern(
block_text, 'css_selector'
)
f_query = ' '.join(query.replace(':', ': ').split())
if f_query in selectors[file]:
selectors[file][f_query].extend(results)
else:
selectors[file][f_query] = results
# pp.pprint(selectors)
return selectors
def get_selectors_html(files):
selectors = {}
for file in files:
results = templates_match_pattern(file, ['html_class', 'html_id'])
selectors[file] = {
'class': results[0],
'id': results[1],
}
return selectors
def file_match_pattern(file, patterns):
with open(file) as f:
data = f.read()
results = string_match_pattern(data, patterns)
return results
def string_match_pattern(data, patterns):
if not isinstance(patterns, str):
results = []
for p in patterns:
re_pattern = re.compile(RE_PATTERNS[p], re.MULTILINE)
results.append(re.findall(re_pattern, data))
else:
re_pattern = re.compile(RE_PATTERNS[patterns], re.MULTILINE)
results = re.findall(re_pattern, data)
return results
def string_replace_pattern(data, patterns):
if not isinstance(patterns, str):
for p in patterns:
re_pattern = re.compile(RE_PATTERNS[p], re.MULTILINE)
data = re.sub(re_pattern, '', data)
else:
re_pattern = re.compile(RE_PATTERNS[patterns], re.MULTILINE)
data = re.sub(re_pattern, '', data)
return data
def templates_match_pattern(template_name, patterns):
t = template.loader.get_template(template_name)
data = t.template.source
results = string_match_pattern(data, patterns)
return results
def get_css_duplication(css_selectors):
# duplicate css selectors in stylesheets
for file in css_selectors:
print(file)
for media in css_selectors[file]:
print(' '.join(media.replace(':', ': ').split()))
print(len(css_selectors[file][media]), 'rules')
# for selector in selectors:
# if selector[0] in count:
# count[selector[0]] += 1
# # print(file, selector[0], count[selector[0]])
# else:
# count[selector[0]] = 1
def write_report(results, filename='frontend'):
full_filename = '../optimize_' + filename + '.csv'
output_file = os.path.join(
settings.PROJECT_DIR, full_filename
)
with open(output_file, 'w', newline='') as f:
w = csv.writer(f)
print(zip_longest(*results))
for r in zip_longest(*results):
w.writerow(r)
html_tags = [
"a",
"abbr",
"address",
"article",
"area",
"aside",
"audio",
"b",
"base",
"bdi",
"bdo",
"blockquote",
"body",
"br",
"button",
"canvas",
"caption",
"cite",
"code",
"col",
"colgroup",
"datalist",
"dd",
"del",
"details",
"dfn",
"div",
"dl",
"dt",
"em",
"embed",
"fieldset",
"figcaption",
"figure",
"footer",
"form",
"h1",
"h2",
"h3",
"h4",
"h5",
"h6",
"head",
"header",
"hgroup",
"hr",
"html",
"i",
"iframe",
"img",
"input",
"ins",
"kbd",
"keygen",
"label",
"legend",
"li",
"link",
"map",
"mark",
"menu",
"meta",
"meter",
"nav",
"noscript",
"object",
"ol",
"optgroup",
"option",
"output",
"p",
"param",
"pre",
"progress",
"q",
"rp",
"rt",
"ruby",
"s",
"samp",
"script",
"section",
"select",
"source",
"small",
"span",
"strong",
"style",
"sub",
"summary",
"sup",
"textarea",
"table",
"tbody",
"td",
"tfoot",
"thead",
"th",
"time",
"title",
"tr",
"u",
"ul",
"var",
"video",
"wbr"
]
bootstrap_classes = [
"active",
]