Lab 9 catflucks implementation with better error handling and tests!

lab-9/cgi-bin/components.py

+#!/usr/bin/env python3
+
+""" 
+	This module provides a set of reuseable functions
+	which provide the main app functionality.
+	We could even go a stage further and separate
+	database interactions from logic...
+"""
+
+# import modules from Python standard library
+from bson.objectid import ObjectId
+from datetime import datetime
+import bcrypt
+
+def login( db, form ):
+	""" Logs a user in if the Username and Password
+	    submitted in a form match a record in database
+
+	Params:
+		db: 	handle to a database
+		form: 	FieldStorage object
+	
+	Returns:
+		Dict 
+	"""
+	# login status is false by default
+	status = False
+	try:
+		# get the username from the form
+		username = form['username'].value
+		# get the unhashed password sent in the form
+		pw = form['password'].value
+	except KeyError:
+		# a field must be missing from the form data
+		response = "I don't think you filled all the fields in..."
+	else:
+		# look for an account with the username
+		account = db.accounts.find_one({
+			"username":username,
+			})
+		# check if an account came back 
+		if account is not None:
+			# compare the unhashed password from the form
+			# with the hashed version in the database
+			if bcrypt.checkpw( pw.encode('utf-8'), account['password'].encode('utf-8') ):
+				# if they match, output a personal greeting
+				# was this a DP student?
+				if account['username'] == "Sunday":
+					response = "What a good kitty. Now fill in the <a href='https://moduleevaluation.gold.ac.uk/surveyPrivacyStatement/Kf4iWgP74kSxYCxRA'>module feedback form</a> and you shall have some pie."
+				else:
+					response = "Hello {}!".format( account['name']['first'] )
+					status = True
+			else:
+				# if not, we know it was a wrong password
+				response = "Wrong password."
+		else:
+			# their username didn't match, so tell them that
+			response = "Sorry, I don't think I know you!"
+	# return a dict with the result and a message
+	return {"status":status,"msg":response}
+
+def register_account( db, form ):
+	""" Registers a new user by inserting an account
+	    in the accounts collection
+
+	Params:
+		db: 	handle to a database
+		form: 	FieldStorage object
+	
+	Returns:
+		Dict 
+	"""
+	# registration status false by default
+	status = False
+	try:
+		# get the username from the form
+		username = form['username'].value
+		# get the email from the form
+		email = form['email'].value
+		# get the unhashed password from the form
+		password = form['password'].value
+	except KeyError:
+		# a field must be missing from the form data
+		response = "I don't think you filled all the fields in..."
+	else:
+		# check if there is already an account with the email
+		# or username
+		result = db.accounts.find_one( { '$or': [
+			{ 'username' : username },
+			{ 'email': email }
+		]} )
+		# if so, send back a useful response
+		if result:
+			if email in result.values():
+				response = "Email address already registered."
+			else:
+				response = "Username taken."
+		# otherwise go ahead and make the account
+		else:
+			hashed_pw = bcrypt.hashpw( password.encode('utf-8'), bcrypt.gensalt() )
+			query = {
+				"username": username,
+				"password": hashed_pw.decode('utf-8'),
+				"is_admin": 0,
+				"created" : datetime.now().timestamp()
+			}
+			# make sure name fields aren't empty
+			# if they are, give them empty string values
+			if 'first' in form:
+				first = form['first'].value
+			else:
+				first = ""
+			if 'last' in form:
+				last = form['last'].value
+			else:
+				last = ""
+			# append name to query
+			query["name"] = { "first": first, "last": last }
+			# insert the account in the database
+			doc = db.accounts.insert( query )
+			if doc:
+				status = True
+				response = "New account registered. <a href='/cgi-bin/splash.py' title='login'>Click here</a> to go Log in!"
+			else:
+				response = "Problem registering your account. Please refresh the page to try again."
+	# return something useful...
+	return {'status': status, 'msg': response}
+
+def latest_fluck( db ):
+	""" Returns details of the most recently flucked
+	    cat in the database
+
+	Params:
+		db: 	handle to a database
+	
+	Returns:
+		Dict 
+	"""
+	# start with an empty dict
+	image = {}
+	# get details of last flucked cat
+	result = db.flucks.find({"is_flucked":1}).sort([('timestamp', -1)]).limit(1)
+	# get the associated image
+	for fluck in result:
+		result2 = db.images.find({"_id":fluck["image_id"]})
+	# if a doc was returned, put the bits we want in the image dict
+	for doc in result2:
+		image = {"url":doc["url"],"alt":doc["alt"]}
+	return image
+
+def most_flucked( db ):
+	""" Returns details of the most flucked
+	    cat in the database
+
+	Params:
+		db: 	handle to a database
+	
+	Returns:
+		Dict 
+	"""
+	# start with an empty dict
+	image = {}
+	# define a pipeline of operations to get most flucked image id
+	# from flucks collection
+	pipeline = [
+		{"$group": {"_id": "$image_id", "count": {"$sum": 1}}},
+		{"$sort": {"count":-1}},
+		{"$limit":1}
+		]
+
+	# apply pipeline of operations using aggregate
+	result = db.flucks.aggregate( pipeline )
+
+	# check if a result was returned
+	if result:
+		for fluck in result:
+			# get the associated image document
+			doc = db.images.find_one({"_id": fluck["_id"]})
+
+	# if a doc was returned, put the bits we want in the image dict
+	if doc:
+		image = {"url":doc["url"],"alt":doc["alt"]}
+	return image
+
+def random_cat( db ):
+	""" Returns details of a random cat in the database
+
+	Params:
+		db: 	handle to a database
+	
+	Returns:
+		Dict 
+	"""
+	# start with an empty dict
+	image = {}
+	# get a random sample from images collection of size '1'
+	result = db.images.aggregate(
+		[{ '$sample': { 'size': 1 } }]
+	)
+	# if a result came back, do stuff with it...
+	if result:
+		# iterate through objects in the cursor (should only be 1)
+		for doc in result:
+			# put the bits we want in the image dict
+			image = {
+				'src': doc['url'],
+				'alt': doc['alt'],
+				'id': doc['_id']
+			}
+	return image
+
+def count_flucks( db, img_id ):
+	""" Returns details of a random cat in the database
+
+	Params:
+		db: 	handle to a database
+		img_id:	object id of an image document
+	
+	Returns:
+		Dict 
+	"""
+	# try to count flucks associated with image id
+	try:
+		num_flucks = db.flucks.find( {"image_id": img_id, "is_flucked":1} ).count()
+	# if img_id invalid, return false rather than crashing
+	except NameError:
+		return False
+	else:
+		return num_flucks
+
+def insert_fluck( db, img_id, is_flucked ):
+	""" Inserts new fluck in flucks collection
+	    based on form data
+
+	Params:
+		db: 	handle to a database
+		form: 	FieldStorage object
+	
+	Returns:
+		Bool 
+	"""
+	# try to insert a fluck
+	query =	{ 
+			"image_id": ObjectId(img_id),
+			"is_flucked":is_flucked,
+			"timestamp":datetime.now().timestamp() 
+		} 
+	try:
+		result = db.flucks.insert( query )
+	# if img_id invalid, return something useful
+	except NameError:
+		return {'status': False, 'query': query}
+	# else return info about the inserted document
+	else:
+		return {'status': True, 'fluck_id': result}
+

lab-9/cgi-bin/config.py

+"""
+	Define global config variables here.
+	These will be accessible from other
+	scripts, so we only need to set them
+	here.
+"""
+
+# app configurables stored in a config object
+config = {
+	"SERVER_ADDRESS": "localhost",
+	"PORT": 27017,
+	"USER": "",
+	"PASS": "",
+	"DATABASE_NAME": "catflucks",
+	"TEMPLATE_DIR": "templates/"
+}

lab-9/cgi-bin/register.py

+#!/usr/bin/env python3
+
+"""
+	This script handles the processing
+	of the register form in the catflucks application.
+	Note: 
+		there is code repetition here...
+		What could we do about that?
+	Also note:
+		this functionality is not yet integrated
+		with the rest of the application.
+		How could it be?
+"""
+
+# import modules from Python standard library
+import cgi
+import cgitb
+cgitb.enable()
+import bcrypt
+
+# import custom modules
+from config import config
+import utils
+import components
+
+# connect to database
+db = utils.db_connect( config )
+
+# tell the browser we are outputting HTML
+print("Content-Type: text/html\n")
+
+# render header HTML
+print( utils.render_template( config['TEMPLATE_DIR'] + 'header.html') )
+
+# get the form data
+form = cgi.FieldStorage()
+
+# check that register form was submitted
+if 'btn_register' in form:
+	result = components.register_account( db, form )
+	msg = result['msg']
+else:
+	msg = ""
+
+# output the form as HTML
+print( utils.render_template( config['TEMPLATE_DIR'] + 'register.html', data=[msg] ) )
+
+# render footer
+print( utils.render_template( config['TEMPLATE_DIR']+'footer.html' ) )

lab-9/cgi-bin/tests.py

+"""
+	This module contains some test functions that
+	can be called to check if a certain component
+	is doing what we expect it to do
+"""
+
+from config import config
+import utils
+import components
+
+def test_connect_db( config ):
+	db = utils.db_connect( config )
+	print(db)
+	if db:
+		print("Connected to database. Trying to get a document...")
+		doc = db.flucks.find_one({})
+		if doc:
+			#print( doc )
+			print("PASS: db_connect")
+	else:
+		print("Error in db_connect. No handle returned.")
+	
+
+def test_insert_fluck( config ):
+	db = utils.db_connect( config )
+	result = components.insert_fluck( db, "5a15779bbc93104b641721d2", 1 )
+	if result['status']:
+		print("PASS: insert_fluck. Fluck {} inserted in database".format(result))
+	else:
+		print(result['query'])
+		print("FAIL: Error in insert_fluck")
+	
+
+# run tests...
+test_connect_db(config)
+test_insert_fluck(config)

lab-9/cgi-bin/utils.py

+#!/usr/bin/env python3
+
+""" 
+	This module provides a set of reuseable utility functions
+	This is a Google style docstring by the way.
+	Read more about them here: 
+	https://www.python.org/dev/peps/pep-0257/
+"""
+
+from pymongo import MongoClient
+
+def db_connect( config ):
+	""" Provides a connection to mongoDB database
+	
+	Returns:
+		Object: A handle to a mongoDB database 
+	"""
+	# try to create instance of MongoClient object
+	try:
+		client = MongoClient( config['SERVER_ADDRESS'], config['PORT'] )
+	except:
+		# raise a custom exception
+		raise Exception("Problem connecting to the database!")
+	# if we have a mongo client...
+	else:
+		# switch to the specified database
+		db = client[ config['DATABASE_NAME'] ]
+
+		# check a handle was returned
+		if db is not None:
+			# return a handle to the database
+			return db
+
+def render_template( temp_path, data=[] ):
+	""" Reads in an HTML string from file
+	    replacing any placeholders with values
+	    supplied in data list.
+
+	    Input params:
+		temp_path: the path to the template file
+		data: optional list of data values
+
+	    Returns:
+		String: A formatted string of HTML
+	"""
+	try:
+		# open and read the template file
+		with open(temp_path, 'r') as f:
+			html = f.read()
+	except:
+		raise Exception("Could not open template")
+	else:
+		if data is not None:
+			try:
+				# replace placeholders with data in list
+				html = html.format(*data)
+			except:
+				raise Exception("Problem parsing data to template")
+		return html	

lab-9/css/style.css

+body {
+	padding: 20px;
+}
+
+.feature-cat {
+	text-align: center;
+	float: right;
+	border: 2px solid #ccc;
+	width: 25%;
+	position: relative;
+	display: block;
+	margin-bottom: 20px;
+	clear: right;
+}
+
+.feature-cat h3 {
+	font-size: 16px;
+}
+
+.feature-cat img {
+	width: 100%;
+}
+
+.col-main {
+	padding: 10px;
+	border: 2px solid #ccc;
+	width: 70%;
+	float: left;
+	display: block;
+	margin-bottom: 20px;
+}
+
+.btn {
+	margin: 2px 0;
+	background-color: #666;
+	color: #fff;
+	cursor: pointer;
+}
+
+.btn-primary {
+	background-color: #563d7c;
+}
+
+.feature-cat.message {
+    position: absolute;
+    top: 100px;
+    left: 100px;
+    background: #eee;
+    width: 600px;
+}

lab-9/simpleServer.py

+#!/usr/bin/env python3
+# above 'she-bang' line makes the script executable from command line
+
+""" A Simple Web Server
+	Run with ./simpleServer.py
+	Make sure all cgi scripts are executable
+	for single script:
+		 chmod +x simpleServer.py
+	or for a whole directory:
+		 chmod -r +x cgi-bin/
+"""
+
+import http.server										# import http.server module
+import cgitb; cgitb.enable()							# import and enable cgitb module for exception handling
+
+PORT = 8000												# specifies the port number to accept connections on
+
+server = http.server.HTTPServer 						# provides simple web server
+handler = http.server.CGIHTTPRequestHandler 			# provides request handler
+server_address = ("", PORT)								# specify server directory and port number
+handler.cgi_directories = ["/","/cgi-bin","/htbin"]		# where CGI scripts will reside in relation to the `server' directory
+
+print("Starting server...")					# outputs a message 
+httpd = server(server_address, handler)		# creates the server, passing it the server address and port number, as well as the CGI handler (httpd stands for HTTP Daemon)
+print("serving at port", PORT)				# outputs a message
+httpd.serve_forever()						# puts program in infinite loop so that the server can `serve_forever'

lab-9/templates/cat_stats.html

+<div class="col-main">
+	<h3>Vital Catistics</h3>
+	<p>This poor cat has been flucked {} times already.</p>
+</div>

lab-9/templates/footer.html

+<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js"></script>
+</body></html>

lab-9/templates/form_fluck.html

+<div class="col-main">
+	<form method="POST" action="{}">
+		<div class="form-group">
+			<input type="hidden" value="{}" name="img_id">
+			<input class="form-control btn" name="btn_skip" type="submit" value="Skip">
+			<input class="form-control btn btn-primary" name="btn_fluck" type="submit" value="Fluck">
+		</div>
+	</form>
+</div>

lab-9/templates/header.html

+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" type="text/css" rel="stylesheet">
+<link rel="stylesheet" type="text/css" href="/css/style.css">
+<title>Catflucks</title>
+</head>
+<body>
+<h1>Welcome to Catflucks</h1>
+

lab-9/templates/latest_fluck.html

+<div class="feature-cat">
+	<h3>Recently flucked</h3>
+	<!-- present most recently flucked cat -->
+	<img src="{}" alt="{}" width=150>
+</div>

lab-9/templates/login.html

+<div class="col-main">
+	<h3>Log in</h3>
+	<form method="POST" action="/cgi-bin/splash.py">
+		<div class="form-group">
+			<label for="username">Username:</label>
+			<input class="form-control" type="text" name="username">
+			<label for="password">Password:</label>
+			<input class="form-control" type="password" name="password">
+			<input class="form-control btn btn-primary" type="submit" name="btn_login" value="Enter">
+		</div>
+	</form>
+	<div class="msg"><p>{}</p></div>
+	<div><a href="/cgi-bin/register.py">Register</a></div>
+</div>

lab-9/templates/most_flucked.html

+<div class="feature-cat">
+	<h3>Most flucked</h3>
+	<!-- present the most often flucked cat -->
+	<img src="{}" alt="{}" width=150>
+</div>

lab-9/templates/register.html

+<!-- THINK: 
+	- What is unusual about this register form?
+	- What are the implications of that?
+	- How might you help a user who has forgotten their password?
+	- FEEL FREE TO IMPROVE THIS FORM!
+-->
+
+<div>
+	<h3>Register</h3>
+	<form method="POST" action="/cgi-bin/register.py">
+		<div class="form-group">
+			<label for="username">Username:</label>
+			<input type="text" name="username" required>
+			<label for="password">Password:</label>
+			<input type="password" name="password" required>
+			<label for="email">Email:</label>
+			<input type="email" name="email" required>
+		</div>
+		<div class="form-group">
+			<label for="first">First name:</label>
+			<input type="text" name="first" placeholder="First name">
+			<label for="last">Last name:</label>
+			<input type="text" name="last" placeholder="Last name">
+		</div>
+		<div class="form-group">
+			<input type="submit" name="btn_register">
+		</div>
+	</form>
+	<div class="msg"><p>{}</p></div>
+</div>

lab-9/templates/serve_cat.html

+<div class="col-main">
+	<p>You are viewing a random image of a cat.</p>
+	<img src="{}" alt="{}" width=500>
+</div>