The cross-browser challenge

Web standards have been growing fast thanks to the World Wide Web Consotrium and the community around it. It's amazing to see what a browser can do with a few lines of html and javascript. But.. What if you need to deliver a new feature to users and you can't implement it using current web standards ?

This often means you will have to develop your own "browser plugin" using native code. What you would like is to have a plugin that runs on every browser, on every operating system, on every hardware architecture.

In order to deliver encrypted RTSP content inside user's browser, WimTV had to face (and is facing) the very same problems. Just like Adobe Flash we had to implement our own piece of software that runs side by side with the browser, rendering contents in a child window.

While there are a lot of browsers available, it's is possible to group them by the rendering engine they use.

- Webkit: Chrome, Safari, Android Mobile Browser, many others
- Gecko: Firefox, Camino
- Trident: Internet Explorer, other Microsoft products

Luckly most Webkit and Gecko browsers implement NPAPI for their plugins.

NPAPI is a cross-platform plugin architecture that was introduced by Netscape and then received many contributions by Mozilla and Google. Basically it defines a set of APIs that must be implemented on both browser and plugin side in order for them to interact. Mozilla currently offers the best SDK and documentation to help developers write their plugins using C or C++.

WimTV Browser Plugin uses NPAPI to support Webkit and Gecko powered browsers, and a NPAPI-ACTIVEX wrapper in order to work on Microsoft Internet Explorer.

The wrapper is called PluginHostController. It is opensource and the code is available from Mozilla servers. It consist of an ActiveX plugin written in C++ and implementing some basic funcions of NPAPI. Unfortunately it was written some years ago and it is not maintained. In the meantime NPAPI evolved adding some features we used in our plugin, such as Scriptable APIs allowing Javascript interaction. In order to use it we had to develop the missing parts and then bundle wrapper and plugin inside a cab file.

Davide Bertola

Behind the scene, the Web APIs

Once upon a time the web used to be a lot different. If you think about it for a second, you'd surely recall that just few years ago the web was all about emails, static web sites and file sharing (either legal or not) .

It's fascinating how much it evolved, and how close the web applications are getting to the old fashion applications you used to install on your laptop.

This was surely because of the evolution of the network itself (growing bigger and faster all over the world) but mainly because lately new paradigms (such as the ad Software as a Service and Web Service ones) came along opening a whole new prospective on how the software can be delivered.

The Wim.tv project started taking deeply in account those new paradigms and focused on delivering a rich user experience to both its business partner and to the consumer joining the platform. But it wasn't until recently that we started to implement a key feature to become successful web platform: a Web API.

When used in the context of web development, an API is typically a defined set of Hypertext Transfer Protocol (HTTP) request messages, along with a definition of the structure of response messages, which is usually in an Extensible Markup Language (XML) or JavaScript Object Notation (JSON) format. While "Web API" is virtually a synonym for web service, the recent trend (so-called Web 2.0) has been moving away from Simple Object Access Protocol (SOAP) based services towards more direct Representational State Transfer (REST) style communications. Web APIs allow the combination of multiple services into new applications known as mashups . This is a key feature of modern web applications because it allows web developers to exploit the APIs in ways never even imagined by the API's development team itself, letting the web evolve. Wim.tv strongly believes in openness and interoperability and it's working hard to provide a simple and reliable Web API to allow other web developers to interact with the platform as much as possible and to integrate our technologies into their web applications.

Alberto Aresca