Webmaster''''s Guide to the Wireless Internet part 51 pps

472 Appendix • Webmaster’s Guide to the Wireless Internet Fast Track Adopting Wireless Standards ; Many wireless standards are out there. Find out what your audience has access to and build your site accordingly. ; WAP is the standard that currently has the most momentum, but this could change as companies experiment and roll out other technologies Noting the Market for Wireless Browsers and Other Applications ; A variety of applications are available for mobile devices.The one you can almost guarantee will be available is the WAP browser, however. ; Java2 Micro Edition is poised as an interesting player in the mobile data arena.You can write an application once that can run on any brand of phone and on any network. ; Old technologies such as SMS are still going strong. Device manufacturers are slowly overcoming the limitations of SMS, and the concept of SMS is being expanded on to include multimedia capabilities. ❖ Chapter 3: A New Markup: WML A Brief History of Wireless Content ; The Intelligent Terminal Transfer Protocol (ITTP) was developed by Ericsson in 1995. Unwired Planet developed the Handheld Device Markup Language (HDML) in mid-1996 and made it available to developers.The Tagged Text Markup Language (TTML), developed by Nokia Corporation, and the Extensible Markup Language (XML) had become available around the same time. ; In June 1997, Nokia and Unwired Planet formed The WAP Forum, also bringing together Motorola and Ericsson.These initial founders represented over 90 percent of the wireless market.The WAP Forum’s primary goal was to develop a protocol that could be built on any platform to allow users to interact with services and information as fast and efficiently as possible and to promote product interoperability. www.syngress.com Chapter 2 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 472 Webmaster’s Guide to the Wireless Internet Fast Track • Appendix 473 ; The WAP Forum examined the various markup languages being offered by the different companies and took the best aspects of each to form the Wireless Markup Language (WML), which was released in 1999. ; Those devices that contained HDML browsers gained the ability to browse WML content from HDML version 3.1 onwards. WML Overview ; WML is an application of XML. ; A WML document contains elements that have a start tag and an end tag.If the element isn’t a container for data, the element must be self-closing (indicated by a backslash). ; WML files consist of a deck containing one or more cards. Each file can be thought of as a deck, within which can be any number of cards. Each card is a single page that can be displayed on the device. ; WML is constructed hierarchically. Files must be well-formed and valid XML documents.Validity is achieved by the inclusion of a Document Type Definition (DTD). WML Elements ; WML elements specify the structure of the content. ; WML is quite similar to HTML in its use of elements and attributes to describe the content within each file.There are relatively few elements in comparison to HTML. Creating WML Content ; Dynamic applications are applications that build content “on the fly” in response to requests made.A single template file filled with dynamically- served content can replace hundreds of similar HTML pages. ; Openwave extensions to WML allow further context and better error handling to be introduced to your WML application. ; WML provides a number of navigation aids that are more flexible than those available in HTML. www.syngress.com Chapter 3 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 473 474 Appendix • Webmaster’s Guide to the Wireless Internet Fast Track ; Tasks allow the user to perform actions dependent on the situation encountered. WML Editors,WAP SDKs, and Emulators ; WAP editors allow the quick and easy creation of WML files. Most of the popular HTML editors support editing WML. ; WAP editors can also sometimes contain a built-in emulator to preview work. ; You should always check WML content on the target device wherever possible. ❖ Chapter 4: Enhancing Client-Side Functionality with WMLScript What Is WMLScript? ; WMLScript is loosely based on the ECMAScript (ECMA262). ; Most devices in the market support WMLScript. ; WMLScript programs are compiled into bytecode by WAP gateways. ; WMLScript is activated by WML decks. Understanding Basic Elements of WMLScript ; WMLScript contains libraries. ; Within each library are functions that provide most commonly needed functionality. Learning to Interpret WMLScript ; WMLScript functions that are preceded by the extern keyword are callable by WML decks. www.syngress.com Chapter 3 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 474 Webmaster’s Guide to the Wireless Internet Fast Track • Appendix 475 Performing Mathematical Operations Using WMLScript ; Variables are declared in WMLScript using the var keyword. ; WMLScript handles data type internally. ; WMLScript supports looping using the for construct. Using WMLScript for Input Validation ; The compare() function in the String library compares two strings. Credit Card Validation ; WMLScript does not support arrays. ; Use a string to improvise an array if needed. Using WMLScript and Microsoft ASP:A Case Study ; A server-side technology like ASP can be used to generate dynamic WMLScript programs. ; WMLScript programs are cached on the client-side. ; Use the HTTP directives to control caching behavior on the client-side. ❖ Chapter 5: Wireless Development Kits The Openwave UP.SDK 4.1 ; The UP.SDK provides emulation for a variety of mobile devices.You can use it to test your application on a variety of phones from multiple device manufacturers as long as they use the UP.Browser in their phones. ; You can download the UP.SDK from the Openwave Developer Program Web site (http://developer.openwave.com) in the Downloads section. www.syngress.com Chapter 4 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 475 476 Appendix • Webmaster’s Guide to the Wireless Internet Fast Track ; The UP.SDK does not provide any text editing or IDE-style capabilities. It is useful for testing applications only, and you must have a separate program to create and edit your WAP files. ; The error messages reported by the UP.SDK are fairly helpful in finding syntactical problems.They will point you in the correct direction but are not explicit enough to make finding errors a simple task. The Nokia WAP Toolkit 2.1 ; The WAP Toolkit provides a prototype-like mobile phone for development. ; You can download modules that emulate actual Nokia phones from the Forum Nokia Web site (http://forum.nokia.com) ; The WAP Toolkit is a full-featured IDE.You can create and edit WML and WMLScript files as well as WBMP images using the built-in tools. ; The error messages reported by the WAP Toolkit are geared more towards machines than humans, but the line numbers they report are usually very close to the source of the problem. The Motorola Mobile Application Development Kit 2.0 ; The Mobile ADK includes support for a large variety of Motorola mobile phones.The Mobile ADK is the only SDK we looked at that also supports voice applications through VoxML and VoiceXML as well as Microsoft ASP support. ; You can download the Mobile ADK from the Motorola Applications Global Network (MAGNET) Web site at www.motorola.com/developers/wireless in the Tools & Downloads section. ; The Mobile ADK and Wireless IDE provide a complete development envi- ronment for your mobile needs.You can integrate with source control prod- ucts and develop for a variety of environments using the same IDE. ; The error reporting in the Mobile ADK is entirely subpar when compared to the other SDKs.The only thing you will find out is that an error occurred with your file.You will have to do all the work of figuring out where the error actually is. www.syngress.com Chapter 5 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 476 Webmaster’s Guide to the Wireless Internet Fast Track • Appendix 477 The Ericsson Mobile Internet WAP-IDE 3.1 ; The WAP-IDE includes support for three Ericsson mobile phones.You can use the emulator independent of the environment for building and debug- ging applications, which provides a good mechanism to demo your WAP applications. ; You can download the Ericsson WAP-IDE from the Ericsson Developer Zone Web site at www.ericsson.com/developerzone. ; The WAP-IDE includes an Application Designer that helps you build WML decks that are syntactically correct as well as compile and debug the ones that aren’t. ; The error reporting is quite descriptive although the line numbers don’t tend to match up that well.Also, it displays a lot of error messages for one error (three in our case), which makes tracking down problems a little more difficult. The Yospace SmartPhone Emulator 2.0 ; The SmartPhone Emulator can emulate a variety of mobile devices from a large variety of manufacturers.Viewing source files in multiple emulators— either individually or at the same time—is quite easy with the layout of the SmartPhone Emulator. It is also written entirely in Java, making it the only emulator that you can use on operating systems other than Microsoft Windows. ; You can download the SmartPhone Emulator from the Yospace Web site (www.yospace.com) in the Products section. ; The SmartPhone Emulator includes no editing capabilities, but it does pro- vide good debugging facilities for viewing variables, history stacks, and other portions of the running WAP browsers. ; The error reporting is the most accurate of the group. It pinpoints the cause of the problem rather than the effect.The error messages are cluttered with a lot of information pertaining to the internal implementation of the SmartPhone Emulator, which makes finding the actual error message a little difficult. Once you do find it however, it points you directly to the error. www.syngress.com Chapter 5 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 477 478 Appendix • Webmaster’s Guide to the Wireless Internet Fast Track ❖ Chapter 6: Web Clipping What Is Web Clipping? ; Web clipping refers to a proprietary network that allows Palm-compatible handheld devices to connect to the Internet by browsing compressed HTML contained in special files installed on the device.The Web Clipping Application Viewer is also called the Clipper browser. ; Web clipping differs from Web browsing both in usage patterns and the actual technology used to access the Internet.WCA users are mobile, and deal with limited input mechanisms. ; A Web clipping application is installed on a device, and cannot be updated until the user installs a new version.This means that extra thought should be put into what interactions are included in a WCA. ; A subset of HTML 3.2 is used to build Web clipping applications. Not all elements of the specification are supported, but many elements are. What Types of Hardware Support Web Clipping ; Devices running the Palm Operating System version 3.5 or higher can take advantage of Web clipping. ; Many devices can access the Internet via Web clipping, including the Palm VII/VIIx connected via Mobitex and other Palm-compatible handhelds connected via the CDPD Network or Mobile Internet Kit. ; The RIM 957 (Blackberry) Pager can browse the content of a WCA if it is accessed via a direct link over the Internet.These devices are unable to follow links to, or display images that the WCA expects to be found locally on the device, such as links using the file: protocol. Working with the Palm OS Emulator ; The Palm Operating System Emulator (POSE) is freely available from the Palm Web site at www.palm.com/dev/tech/tools/. ; In order to use the POSE, first you need to install the emulator to emulate the hardware, and then install a ROM image of the OS to start the emulator or run any software. www.syngress.com 159_wg_wi_AppFT 10/23/01 2:42 PM Page 478 Webmaster’s Guide to the Wireless Internet Fast Track • Appendix 479 ; There are two ways to obtain ROM images: transfer one from a device that you own, or download one from the Palm Resource Pavilion.You must reg- ister as a Palm developer to obtain ROM images from Palm. ; It is necessary to configure the emulator to access the Internet via the net- work interface of the computer upon which it is installed.The emulator must be set to redirect network requests to TCP/IP, and the emulator soft- ware must be configured to use a Palm.net Proxy Server. Creating a Web Clipping Project with the Web Clipping Application Builder ; The Web Clipping Application (WCA) Builder, like the POSE, can be downloaded from the Palm Web site at www.palm.com/dev/tech/tools/. ; The WCA Builder is used to compile device-resident Web clipping applica- tions from HTML and images. ; The WCA Builder automatically will scan HTML from a single index page and automatically include any linked pages or referenced images. It will do some basic error checking, but it is not foolproof, and code should be vali- dated externally. ; Custom icons may be used for your Web clipping applications.These can be selected in the Build PQA dialog box, which is the final step in the appli- cation building process. Web Clipping Basics and Examples ; Many of the more common tags from the HTML 3.2 specification are avail- able, but many other recent developments are not.Any elements that require client-side processing, such as animated images, imagemaps, and client-side scripting have been eliminated due to device constraints. ; Some useful features are unique to Web clipping, including variables that relay information about the location of the user and a unique device identi- fier.Two other elements are available: datepicker and timepicker.These ele- ments help to offset the device constraints of Web clipping. ; Data transmitted over the air should be minimized as much as possible, and local resources on the device should be leveraged to minimize network www.syngress.com Chapter 6 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 479 480 Appendix • Webmaster’s Guide to the Wireless Internet Fast Track traffic.This can be accomplished by linking to local images on the device, and by including content that is not time-sensitive on the device. ❖ Chapter 7: Deck of Cards: Designing Small Viewpoint Content Thinking In the Hand, not On the Web ; The wireless Internet provides us with a smaller viewpoint for content, and it is not possible to represent the typical pyramidal site structure of the WWW on handheld devices. ; It is difficult to provide both horizontal and vertical navigation on a mobile device due to a lack of screen real estate. ; The needs of the mobile user necessitate a fairly linear, task-based navigational scheme, with a frequency of access-based segregation of tasks. ; Working within the bandwidth and input constraints of the wireless medium can prevent the mistakes that are typically made by many Webmasters. Stacking a Deck of Cards ; It is possible to make many small refinements to your markup that will have a cumulative effect on the final size of your content. ; A hub-and-spoke metaphor can be used effectively within the framework of WML. Users have full freedom of vertical navigation, though this metaphor does not use horizontal navigation. ; Minimizing the number of server connections can greatly increase a site’s usability, and one of the easiest ways to do this for small sites is to send one deck consisting of navigation, and, on request, send decks that contain the sections’ content. ; WML variables are stored on the device (similar to cookies), and are persis- tent between decks as well as cards.You should be aware of the state of the user’s variables in your application, and clear them as appropriate. www.syngress.com Chapter 6 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 480 Webmaster’s Guide to the Wireless Internet Fast Track • Appendix 481 Examining Display Differences Between Browsers ; One of the most notable differences between the UP.Browser and the Nokia browser is in the rendering of the <SELECT> and <INPUT> elements. On average, the Nokia browser user will need to enter twice as many keystrokes. ; The 4thpass Kbrowser (for the Palm OS) renders WML differently than either the Nokia or the UP.Browser. If you are supporting this browser in your site, you should take care to branch your code and test your application thoroughly. ❖ Chapter 8: Wireless Enabling Your Big Bandwidth Site Defining WAP MIME Types ; It is important to consider the market for which you are delivering content, and to define the appropriate MIME types for the devices used by your users. ; There are several options for defining MIME types under the most common Web servers on the market. MIME types may be defined and Wireless con- tent may be deployed at the directory, site, or server level. ; WAP MIME types are defined in the same manner as any other MIME type. Detecting WAP Devices ; WAP devices send the same type of header information to Web servers as desktop browsers do. ; HTTP_ACCEPT can be used to detect the language that a given browser can accept. ; HTTP_USER_AGENT can be used to differentiate browsers depending on the reported name of the browser. ; A combination of HTTP_ACCEPT and HTTP_USER_AGENT can be used to redirect devices to appropriate content, or to profile devices for formatting. www.syngress.com Chapter 7 Continued 159_wg_wi_AppFT 10/23/01 2:42 PM Page 481 . Webmaster’s Guide to the Wireless Internet Fast Track ; Tasks allow the user to perform actions dependent on the situation encountered. WML Editors,WAP SDKs, and Emulators ; WAP editors allow the quick. variables, history stacks, and other portions of the running WAP browsers. ; The error reporting is the most accurate of the group. It pinpoints the cause of the problem rather than the effect .The error. www.palm.com/dev/tech/tools/. ; In order to use the POSE, first you need to install the emulator to emulate the hardware, and then install a ROM image of the OS to start the emulator or run any software. www.syngress.com 159_wg_wi_AppFT