Book Image

Opa Application Development

By : Li Wenbo
Book Image

Opa Application Development

By: Li Wenbo

Overview of this book

Opa is a full-stack Open Source web development framework for JavaScript that lets you write secure and scalable web applications. It generates standard Node.js/MongoDB applications, natively supports HTML5 and CSS and automates many aspects of modern web application programming. It handles all aspects of web programming written in one consistent language and compiled to web standards.Opa Application Development is a practical,hands-on guide that provides you with a number of step-by-step exercises. It covers almost all aspects of developing a web application with Opa, which will help you take advantage of the real power of Opa, as well as building a secure, powerful web application rapidly.Opa Application Development dives into all concepts and components required to build a web application with Opa. The first half of this book shows you all of the basic building blocks that you will need to develop an Opa application, including the syntax of Opa, web development aspects, client and server communication and slicing, plugin, database, and so on. By the end of the book you will have yourself created a complete web application along with a game: Pacman!
Table of Contents (18 chapters)
Opa Application Development
About the Author
About the Reviewers

Binding JavaScript

Opa allows binding of the external functions through its Binding System Library (BSL). If we surf the source code of Opa, we will find in many places that Opa binds JavaScript in its source code. Actually, Opa provides three forms of binding syntax: classic , jsdoc, and new. The jsdoc syntax is now (Opa 1.1.0) the default.

The first example

Let's get started with a binding example of JavaScript. Suppose we have finished a test function in the test.js JavaScript file, and then we want to use it in the 601.opa Opa file.

The content of the test.js file is as follows:

* A test function of Opa binding
* @register {string -> void}
function test(str){

We registered the test function using the annotation @register {string -> void}. This indicates that the function being registered has the string -> void type. To invoke the test function in Opa code, we designate the function as an external JavaScript function by surrounding the name of the function...