Working with Views

For any web application, it is very important to control how you interact with web requests and the proper responses to be catered for these requests. This chapter takes us through the various methods of handling requests properly and designing them in the best way.

Flask offers several ways of designing and laying out the URL routing for our applications. Also, it gives us the flexibility to keep the architecture of our views as just functions or to create classes, which can be inherited and modified as required. In earlier versions, Flask just had function-based views. Later, however, in version 0.7, inspired by Django, Flask introduced the concept of pluggable views, which allows us to have classes and then write methods in these classes. This also makes the process of building a RESTful API pretty simple. Also, we can always go a level deeper into Werkzeug and use the more flexible, but slightly complex, concept of URL maps. In fact, large applications and frameworks prefer using URL maps.

In this chapter, we will cover the following recipes:

• Writing function-based views and URL routes
• Writing class-based views
• Implementing URL routing and product-based pagination
• Rendering to templates
• Dealing with XHR requests
• Using decorators to handle requests beautifully
• Creating custom 404 and 500 handlers
• Flashing messages for better user feedback
• Implementing SQL-based searching