Database Reference
In-Depth Information
the Java compiler. When a method is compiled by Java, it is converted
to instructions called byte code and then largely disappears from the Java
environment, except when it is called by other methods. In a functional
language, functions are treated the same way as data. They can be stored
in objects the same way as integers or strings, returned from functions, and
passed to other functions. This feature is heavily used in many different
client-side JavaScript frameworks, including the D3 framework used in this
topic. The D3 framework, which stands for Data Driven Documents, uses
functions to represent equations that it uses to manipulate web pages. For
example, a function can be passed to the method of an object that tells
a rectangle where to appear on the page. This allows the framework to
respond to data coming from outside sources without a lot of overhead.
JavaScript is also increasingly found in the implementation of the delivery
server itself, primarily in the form of the node.js project found at
http://nodejs.org
.
This project combines the JavaScript engine from the
Chrome web browser, known as V8, with an event loop library. This allows
the inherently single-threaded server to implement event-driven network
services that can handle large numbers of simultaneous connections.
Although not nearly as efficient as the modern Java frameworks, it is
generally sufficient for the implementation of the server that handles
delivery of data to the front end. It also has an advantage over a
non-JavaScript-based server in that the fallback support for browsers that
do not support modern features, such as SVG and Canvas, can be
implemented on the server side using the same codebase as the client side.
In particular, node.js has packages that allow for the creation of a DOM and
arenderingservicethatallowsfortherenderingofSVGvisualizationsonthe
server side rather than the client side.
The Go Language
Although it's not used in this topic, the Go language is an interesting new
entry in the realm of high-performance application development, including
real-time applications. Developed at Google by a fairly small team, the Go
language combines the simplicity of the C language with a framework for
developing highly concurrent applications. It shares core team members
with the original UNIX team and the developers of the C language, which
makes the similarity to C unsurprising.
