Smell webOS on S60 or Nokia WRT Widgets

I ignored the “Web Technologies” section on the Nokia forum for a very long time, thinking that there are described how to create web pages for mobile phones. As it turned out - in vain. Behind it was a description of the WRT (Web RunTime) platform, which is very convenient for a web developer to write simple mobile programs called widgets.

The widget is essentially a regular web page, but for the user it looks like a separate standalone program, indistinguishable from traditional applications. To use and write widgets do not require symbian-certification, they are zip-archives, but they are installed automatically, like other S60 applications

At the moment, widgets are supported by phones on the S60 3rd FP 2 and S60 5th platforms (a growing list of phones with widget support can be viewed here ), also the widgets are supported by some S60 devices from other manufacturers.
')

Because In the latest models of S60 phones built browser based on WebKit, you can count on all the features of this engine.
Nokia has announced support for the following technologies:

• HTML 4.01
• XHTML Mobile Profiles
• CSS Level 2 revision 1 (CSS 2.1), WAP CSS
• JavaScript 1.5 (ECMA-262 3rd Edition)
• Dom
• Ajax

Also, widgets use Flash Lite 3, but for some reason it is not yet declared to the Nokia Library as officially supported.
The functionality of the widgets is not limited to the capabilities of the integrated browser. Nokia has extended classic JavaScript by giving access to the following features:

WRT 1.0+

• Widget data storage (similar to cookies that are not available, is most often used for settings)
• Changing and assigning functions to buttons in the application menu (soft keys)
• Information about the system and the state of the phone
• Key illumination and vibration function

WRT 1.1+

• Access to information about installed applications, their launch
• Access to calendar information
• Access to the address book
• Access to navigation
• Access to information about calls made (Log)
• Access to information about files in the gallery (but there is no access to the files themselves)
• Receive and send messages
• Accelerometer Access

Widgets do not have access to the camera, Bluetooth, WiFi control and file system - for security reasons and because of their focus. However, there is a technique for using a web server application (which, by the way, is written in python) to access the necessary information through it, via HTTP.
As already mentioned, the widget is a zip archive (with the WGZ extension), the content of which differs from a regular web page only in the presence of an XML description file. For familiarization, you can unzip any ready-made widget, for example STEW ( the widget itself , a description ).

To develop complex widgets, it makes sense to install the SDK , it has support for reports on JavaScript errors, a log, and working with the emulator is more convenient during development. For debugging widgets, you can use any JS debugger, the same FireBug (although it is more logical to use debuggers with webkit support), but you need to adapt the script if it contains phone-specific code. For example, pre-replace such code compatible with classic browsers, or create objects that will emulate phone-specific functions.

So far, not everything is as rosy as it seems at first glance. Some “dampness” of the platform is felt, and some offensive trifles, such as the inability to work in the background (excluding the still obscure widgets for the main screen), a noticeable delay between clicking on the element and the reaction of the widget, glitches with the development of some JS events (onkeyup, onkeydown, onchange), problems with virtual keyboards. At the same time, it is good that the platform is being developed and finalized, new sections in the documentation appear.

Links to mana and examples (English)
Nokia web developer library
Widgets on forum.nokia.com (Landing Pad)
Information about widgets on nokia wiki + examples