Book Image

D Web Development

By : Kai Nacke
Book Image

D Web Development

By: Kai Nacke

Overview of this book

D is a programming language with C-like syntax and static typing. The vibe.d framework builds on powerful D concepts like template meta-programming and compile-time function execution to provide an easy-to-use environment for web applications. The combination of a feature-rich web programming framework with a language compiling to native code solves two common issues in web development today: it accelerates your development and it results in fast, native web applications. Learning the vibe.d framework before you start your application will help you to choose the right features to reach your goal. This book guides you through all aspects of web development with D and the vibe.d framework. Covering the popular operating systems today, this guide starts with the setup of your development system. From the first Hello World-style application you will move on to building static web pages with templates. The concise treatment of web forms will give you all the details about form handling and web security. Using the abstractions of the web framework you will learn how to easily validate user input. Next, you will add database access to your application, providing persistent storage for your data. Building on this foundation, you will expose your component and integrate other components via REST. Learning about the internals of vibe.d you will be able to use low-level techniques such as raw TCP access. The vibe.d concepts can also be used for GUI clients, which is the next topic that you will learn. vibe.d is supported by an active community, which adds new functionality. This comprehensive guide concludes with an overview of the most useful vibe.d extensions and where to find them. It also shows you how to integrate these extensions in your application. The concepts are always illustrated with source code, giving you an insight into how to apply them in your application.
Table of Contents (17 chapters)
D Web Development
About the Author
About the Reviewers

Validating user input

With the use of the web framework, the application implicitly checks that the form fields for the topic and content text are present. The check happens at the time the framework populates the FormData struct with the values of the form fields. There is no way to display this error yet. If you remove one of the form fields and run the application, then the application seems to crash. As the same approach is used to validate user input, we need to fix this.

Displaying error messages with @errorDisplay

If an error occurs, then a web page must be rendered to show the error message. You use the @errorDisplay annotation to define the function to be called in order to display the error:

void createNewNote(FormData form) { /* ... */ }

The getError() method takes a _error parameter, which receives information about the error. In the simplest cases, the type of the parameter is string and contains an error message. Note the underscore in the parameter name...