Abstract
This chapter depicts, from a comprehensive perspective, the state of the art of the mobile Web application development, ranging from the traditional transcoding techniques used to enable mobile browsing from early Web-enabled devices to innovative and ambitious proposals based on detecting an extensively described context and adapting to it. The chapter discusses the main solutions being adopted for adapting mobile Web applications and contexts to multiple devices and contexts, and outlines the newest trends on full-fledged context-aware adaptation that give a step forward on device-based adaptation and pursue the creation of applications that satisfy the emerging user needs about context- and location-based information and services. As a case of success, the MyMobileWeb project is studied in depth.
TopDeveloping A Mobile Web Application
The development of mobile Web contents or applications has been marked by the existence of a mesh of protocols, markup languages and formats. This posed a challenge to mobile Web developers who had to tackle a wide range of technologies. Additionally, they were obliged by the reduced set of technologies supported by individual device models, and the big differences from one device to another to deliver a tailored version of the Web contents or application for each model.
The need for device-specific application versions suggested the design of techniques to automate the creation of multiple versions, the transcoding of resources and markup languages, as well as the adaptation of the user interface to fit the capabilities of each device.
In the following we introduce a significant set of mobile Web technologies, the key adaptation techniques developed and some recommendations or standards created to support the development of quality mobile Web contents.
Key Terms in this Chapter
Transcoding: A simplistic, early approach to adaptation based on the modification of the component layout, translating the markup language and rearranging and resizing the elements making up the Web interface of the target application. It can also be defined as the process of changing the format, representation or encoding of a document, while keeping as much information as possible from the original source.
Delivery Context: A set of attributes that characterizes the capabilities of the access mechanism, the preferences of the user and other aspects of the context into which a web page is to be delivered. This includes, for instance, physical and logical display size, supported media formats, available input/output mechanisms, QoS attributes, etc.
Mobile Web: Term covering the whole set of techniques and protocols used to enable the access to all the information and services deployed over the Internet ubiquitously from mobile devices, considering their restricted interface features
Authoring Languages: A notation used to control de appearance and functionality of webpages when displayed in a browser.
DIAL: The Device Independent Authoring Language provides a markup language for filtering and rendering available Web page content across different delivery contexts, and thus facilitates an optimal user experience by adaptation.
WURFL: Created by Luca Passani and Andrea Trasatti in 2001, WURFL has represented for years the “de facto” standard for Device Description Repository (DDR), which basically consist of an XML document indicating hierarchically organized device features using the HTTP Request User-Agent header as the search key within the WURFL file.
Context: Any information that characterizes the situation of any entity taking part in and influencing the communication act. The most exploited aspect of context in mobile Web contextualization is by far location.
Mobile Web site: A Web site designed for the small screens of mobile phones. Queries to a Web site include the type of browser being used, and when a request from a mobile browser is made, it is redirected to the mobile version for a significantly better browsing experience.