Flask by Example

Cover
Copyright
Credits
About the Author
Acknowledgements
About the Reviewers
www.PacktPub.com
Table of Contents
Preface
Chapter 1: Hello, World!
Introducing Flask
Creating our development environment
Installing pip
Installing Flask
Writing "Hello, World!"
Writing the code
Running the code
Deploying our application to production
Setting up a Virtual Private Server
Configuring our server
Installing and using Git
Serving our Flask app with WSGI
Configuring Apache to serve our Flask application
Summary
Chapter 2: Getting Started with Our Headlines Project
Setting up our project and a Git repository
Creating a new Flask application
Introduction to RSS and RSS feeds
Using RSS from Python
URL routing in Flask
Publishing our Headlines application
Summary
Chapter 3: Using Templates in Our Headlines Project
Introducing Jinja
Basic use of Jinja templates
Rendering a basic template
Passing dynamic data to our template
Displaying dynamic data in our template
Advanced use of Jinja templates
Using Jinja objects
Adding looping logic to our template
Adding hyperlinks to our template
Pushing our code to the server
Summary
Chapter 4: User Input for Our Headlines Project
Getting user input using HTTP GET
Getting user input using HTTP POST
Creating a branch in Git
Adding POST routes in Flask
Making our HTML form use POST
Reverting our Git repository
Adding weather and currency data
Introducing the OpenWeatherMap API
Signing up with OpenWeatherMap
Retrieving your OpenWeatherMap API key
Parsing JSON with Python
Introducing JSON
Retrieving and parsing JSON in Python
Using our weather code
Displaying the weather data
Allowing the user to customize the city
Adding another search box to our template
Using the user's city search in our Python code
Checking our new functionality
Handling duplicate city names
Currency
Getting an API key for the Open Exchange Rates API
Using the Open Exchange Rates API
Using our currency function
Displaying the currency data in our template
Adding inputs for the user to select currency
Creating an HTML select drop-down element
Adding all the currencies to the select input
Displaying the selected currency in the drop-down input
Summary
Chapter 5: Improving the User Experience of Our
Headlines Project
Adding cookies to our Headlines application
Using cookies with Flask
Setting cookies in Flask
Retrieving cookies in Flask
Adding CSS to our Headlines application
External, internal, and inline CSS
Adding our first CSS
Adding padding to our CSS
Adding more styles to our CSS
Adding the div tags to the template file
Styling our inputs
Summary
Chapter 6: Building an Interactive
Crime Map
Setting up a new Git repository
Understanding relational databases
Installing and configuring MySQL on our VPS
Installing MySQL on our VPS
Installing Python drivers for MySQL
Creating our Crime Map database in MySQL
Creating a database setup script
Creating the database
Looking at our table columns
Indexing and committing
Using the database setup script
Adding credentials to our setup script
Running our database setup script
Creating a basic database web application
Setting up our directory structure
Looking at our application code
Looking at our SQL code
Reading data
Inserting data
Deleting data
Creating our view code
Running the code on our VPS
Mitigating against SQL injection
Injecting SQL into our database application
Mitigating against SQL injection
Summary
Chapter 7: Adding Google Maps to Our Crime Map Project
Running a database application locally
Creating a mock of our database
Adding a test flag
Writing the mock code
Validating our expectations
Adding an embedded Google Maps widget to our application
Adding the map to our template
Introducing JavaScript
The body of our HTML code
Testing and debugging
Making our map interactive
Adding markers
Using a single marker
Adding an input form for new crimes
The HTML code for the form
Adding external CSS to our web application
Creating the CSS file in our directory structure
Adding CSS code
Configuring Flask to use CSS
Viewing the result
Publishing the result
Linking the form to the backend
Setting up the URL to collect POST data
Adding the database methods
Testing the code on the server
Displaying existing crimes on our map
Getting data from SQL
Passing the data to our template
Using the data in our template
Viewing the results
Summary
Chapter 8: Validating User Input in Our Crime Map Project
Choosing where to validate
Identifying inputs that require validation
Trying out an XSS example
The potential of persistent XSS
Validating and sanitizing
White and blacklisting
Validating versus sanitizing
Implementing validation
Validating the category
Validating the location
Validating the date
Validating the description
Summary
Chapter 9: Building a Waiter Caller App
Setting up a new git repository
Setting up the new project locally
Setting up the project on our VPS
Using Bootstrap to kick-start our application
Introducing Bootstrap
Downloading Bootstrap
Bootstrap templates
Adding user account control to our application
Introducing Flask-Login
Installing and importing Flask-Login
Using Flask extensions
Adding a restricted route
Authenticating a user
Creating a user class
Mocking our database for users
Logging in a user
Adding imports and configuration
Adding the login functionality
Checking the login functionality
Logging out a user
Registering a user
Managing passwords with cryptographic hashes
Implementing secure password storage in Python
Summary
Chapter 10: Template Inheritance and WTForms in Waiter Caller Project
Adding the Account and Dashboard pages
Introducing Jinja templates
Creating the base template
Creating the dashboard template
Creating the account template
Creating the home template
Adding the routing code
Creating restaurant tables
Writing the restaurant table code
Testing the restaurant table code
Shortening URLs using the bitly API
Introducing Bitly
Using the bitly API
Getting a bitly oauth token
Creating the bitlyhelper file
Using the bitly module
Adding functionality to handle attention requests
Writing the attention request code
Adding the attention request route
Adding the attention request database code
Add the get and delete methods for attention requests
Modifying the dashboard route to use attention requests
Modifying the template code to display attention requests
Adding the resolve request application code
Testing the attention request code
Auto-refreshing the dashboard page
Adding user feedback with WTForms
Introducing WTForms
Installing Flask-WTF
Creating the registration form
Rendering the registration form
Updating the application code
Updating the template code
Testing the new form
Using WTForms in our application code
Displaying errors to our user
Testing the final registration form
Adding a successful registration notification
Modifying the login form
Creating the new LoginForm in the application code
Using the new LoginForm in the template
Modifying the create table form
Summary
Chapter 11: Using MongoDB with Our Waiter Caller Project
Introducing MongoDB
Installing MongoDB
Using the MongoDB shell
Starting the MongoDB shell
Running commands in the MongoDB shell
Creating data with MongoDB
Reading data with MongoDB
Updating data with MongoDB
Deleting data with MongoDB
Introducing PyMongo
Writing the DBHelper class
Adding the user methods
Adding the table methods
Adding the request methods
Changing the application code
Testing our application in production
Adding some finishing touches
Adding indices to MongoDB
Where do we add indices?
Adding a favicon
Summary
Appendix: A Sneak Peek into the Future
Expanding the projects
Adding a domain name
Adding HTTPS
E-mail confirmation for new registrations
Google Analytics
Scalability
Expanding your Flask knowledge
VirtualEnv
Flask Blueprints
Flask extensions
Flask-SQLAlchemy
Flask MongoDB extensions
Flask-MongoEngine
Flask-Mail
Flask-Security
Other Flask extensions
Expanding your web development knowledge
Summary
Index