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import os
import re
import sys
import traceback
from http.server import HTTPServer, BaseHTTPRequestHandler
try:
from pygments import highlight
from pygments.lexers import PythonLexer
from pygments.formatters import HtmlFormatter
have_pygment = True
except ModuleNotFoundError:
have_pygment = False
posts = {}
gets = {}
def format_py(code):
if have_pygment:
formatter = HtmlFormatter()
formatter.noclasses = True # inline styles
return highlight(code, PythonLexer(), formatter)
else:
return "<code>{}</code>".format(code).replace("\n", "\n<br>") \
.replace(" ", " ")
def find_get(path):
""" [Internal] - Used by the Handler class to try and
find the correct handler for a GET request.
"""
if path not in gets:
return 404, ""
try:
return 200, gets[path]()
except Exception:
tb = traceback.format_exc()
print(tb, file=sys.stderr)
return 500, format_py(tb)
def find_post(path, request):
""" [Internal] - Used by the Handler class to try and
find the correct handler for a POST request.
"""
if path not in posts:
return 404, ""
try:
return 200, posts[path](request)
except Exception:
tb = traceback.format_exc()
print(tb, file=sys.stderr)
return 500, ""
def get_relative_path():
return os.path.dirname(os.path.abspath(__file__))
def read_html(relative_file_path):
""" Reads the html file on the file location provided
and injects any external files (marked with {{file_path}} )
that may be present. Returns the html content as a string.
Example:
>>> html_string = read_html('templates/index.html')
"""
dir_path = get_relative_path()
file_path = os.path.join(dir_path, relative_file_path)
with open(file_path) as file:
html_content = file.read()
html_content = inject_external_files(html_content)
return html_content
def inject_external_files(html_content):
""" [Internal] - Replaces {{ 'file_path' }} with the file content of that file
pat. Useful for seperation of javascript and css files.
Uses regex to capture the pattern. Here is a link to see how it
works: https://regex101.com/r/v917NK/2
"""
# https://regex101.com/
pattern = r'{{([^}]+)}}'
external_files = re.findall(pattern, html_content)
new_html_content = html_content
for match in external_files:
external_file_path = match.replace(' ', '')
external_file = open(os.path.join(get_relative_path(), external_file_path))
file_content = external_file.read()
external_file.close()
if match.find('.css') != -1:
file_content = '<style>\n' + file_content + '</style>'
elif match.find('.js') != -1:
file_content = '<script>\n' + file_content + '</script>'
to_be_replaced = '{{' + match + '}}'
new_html_content = new_html_content.replace(to_be_replaced, file_content)
return new_html_content
def post(route='/'):
""" A decorator that takes in the route path as argument, and then
puts the post handler in the dictionary, with the route as a key.
The handler will receive one `str` argument called 'body',
where the body of the post request will exist. """
def decorator(handler_function):
posts[route] = handler_function
return handler_function
return decorator
def get(route='/'):
""" A decorator that takes in the route path as argument, and then
puts the get handler in the dictionary, with the route as a key.
The handler function should return either `bytes` or `str`. """
def decorator(handler_function):
gets[route] = handler_function
return handler_function
return decorator
# Explanation: https://blog.anvileight.com/posts/simple-python-http-server/
class Handler(BaseHTTPRequestHandler):
""" [Internal] - The class responsible for handling all the
different requests made to our server.
"""
def do_GET(self):
""" Tries to find the handler for this GET request. The handler can
return either `bytes` or `str`.
"""
status, res = find_get(self.path)
self.send_response(status)
self.send_header("Content-type", "text/html")
self.end_headers()
if hasattr(res, 'encode'):
self.wfile.write(res.encode())
else:
self.wfile.write(res)
def do_POST(self):
""" Tries to find the handler for this POST request. The handler
will get the 'body' of the request as the argument. The body
is a `str`, formatted in JSON.
"""
content_length = int(self.headers['Content-Length'])
body = self.rfile.read(content_length)
status, res = find_post(self.path, body.decode('utf-8'))
self.send_response(status)
self.end_headers()
self.wfile.write(res.encode())
def run_server(port=8314):
server_address = ('127.0.0.1', port) # Should make the port a command line argument
server = HTTPServer(server_address, Handler)
print('Starting server on http://{}:{}.'.format(*server_address))
server.serve_forever()
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