Flask By Example电子书

Flask By Example

Table of Contents

Flask By Example

Credits

About the Author

Acknowledgements

About the Reviewers

www.PacktPub.com

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Why subscribe?

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

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

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

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

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

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

Writing the fallback logic to check for cookies

Retrieving the cookies for other data

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

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

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

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

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

Writing the login function

Creating the load_user function

Checking the login functionality

Logging out a user

Registering a user

Managing passwords with cryptographic hashes

Python hashlib

Reversing hashes

Salting passwords

Implementing secure password storage in Python

Creating the PasswordHelper class

Updating our database code

Updating our application code

Summary

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

Adding the create table form

Adding the create table route

Adding the create table database code

Adding the view table database code

Modifying the account route to pass table data

Modifying the template to show the tables

Adding the delete table route to our backend 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

Displaying the errors in our template

Adding CSS for the errors

Testing the final registration form

Adding a successful registration notification

Passing the message from the application code

Using the message in the template code

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

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

A. 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-MongoAlchemy

Flask-PyMongo

Flask-MongoEngine

Flask-Mail

Flask-Security

Other Flask extensions

Expanding your web development knowledge

Summary

Index