Chapter 4. Please Fill in This Form, Madam
Have you ever imagined what happens when you fill in a form on a website and click on that fancy Send button at the end of it? Well, all the data you wrote—comment, name, checkbox, or whatever—is encoded and sent through a protocol to the server, which then routes that information to the Web application. The Web application will validate the data origin, read the form, validate the data syntactically then semantically, and then decide what to do with it. Do you see that long chain of events where every link might be the cause of a problem? That's forms for you.
In any case, there is nothing to fear! Flask can help you in those steps but there are also tools specifically designed for this purpose. In this chapter, we will learn:
- How to write and handle forms with Flask
- How to validate form data
- How to use WTForms to validate forms with Flask
- How to implement cross-site request forgery protection
This will actually be a fairly...
