Taking Your Talent to the Web: A Guide for the Transitioning Designer- P17 ppt

Recognize that developers bash their brains out writing code like this because browsers behave so inconsistently from version to version and platform to platform. Be glad you’re going into web design and not web development. Be kind to your programmers. On the off-chance that you find this stuff enthralling or decide to switch from design to development, you’ll find an abundance of good browser detection information at http://webreference.com/tools/browser/ javascript.html and http://developer.netscape.com/viewsource/ krock_v5.html. Unfortunately, there is always the chance that by the time you read this book, these pages will have moved or disappeared. If so, check the Resources Department at http://www.webstandards.org/ for the latest on browser detection. GOING GLOBAL WITH JAVASCRIPT Just as with style sheets (Chapter 10), it is possible and often desirable to save time, hassles, and bandwidth by creating one or more global JavaScript documents, which can then be used to control whole sections of your site—or even the entire site. For instance, the “My Glamorous Life” section at zeldman.com (http:// www.zeldman.com/glamorous/) is controlled by a single JavaScript docu- ment (http://www.zeldman.com/glamorous/glam.js). The document, in its entirety, reads as follows: // Menubar preload. Pretty standard stuff. function newImage(arg) { if (document.images) { rslt = new Image(); rslt.src = arg; return rslt; } } function changeImages() { if (document.images && (preloadFlag == true)) { for (var i=0; i<changeImages.arguments.length; i+=2) { document[changeImages.arguments[i]].src = changeImages.arguments[i+1]; } 321 Taking Your Talent to the Web 15 0732 CH11 4/24/01 11:23 AM Page 321 } } var preloadFlag = false; function preloadImages() { if (document.images) { tocover = newImage(“ /omen2/coreover.gif”); funover = newImage(“ /omen2/funover.gif”); alaover = newImage(“ /omen2/alaover.gif”); 15over = newImage(“ /omen2/15over.gif”); stealover = newImage(“ /omen2/stealover.gif”); webover = newImage(“ /omen2/webover.gif”); miscover = newImage(“ /omen2/miscover.gif”); comingover = newImage(“ /glareon.gif”); preloadFlag = true; } } // Get out of some idiot’s frame. if (top != self) { top.location = self.location; } // Popup window, 640 x 480 function open_window6(url) { mywin = window.open(url,”win”,’toolbar=0,location=0,directories=0,status=0,menubar=0, ➥scrollbars=0,resizable=0,width=640,height=480’); } // Popup window, 500 x 500 function open_window(url) { mywin = window.open(url,”win”,’toolbar=0,location=0,directories=0,status=0,menubar=0, ➥scrollbars=0,resizable=0,width=500,height=500’); } Pretty “light” after all that stuff from Juxt Interactive, eh? By now it should be obvious what this stuff means, but we’ll spell it out anyway because we really, truly love you. The double slashes // precede comments. The comments help the author remember what each function is for. The double slashes tell the browser to ignore these comments and proceed to the next function. The menu bar preload and subsequent changeImages function are just another way of preloading images and creating image rollovers. The images in this case are referenced via relative URLs ( /glareon.gif), as explained in Chapter 8. It would have been smarter to use absolute URLs, but we never claimed to be all that bright. 322 HOW: The Joy of JavaScript: Going Global with JavaScript 15 0732 CH11 4/24/01 11:23 AM Page 322 Get out of some idiot’s frame is a simple framebuster script, consisting of just one line. if (top != self) { top.location = self.location; } A third-party site might link to yours. Sometimes that third-party site uses frames. Sometimes those frames are poorly constructed. Your site might load inside their frames instead of in its own window. This line of JavaScript prevents that from happening. In English, what it is saying is, “The HTML document referenced by this script should fill the browser window. If it does, swell. If it doesn’t, get rid of any extraneous frames and fill the browser window with our page, not some other jerk’s.” Of course JavaScript syntax is a bit more formal than that. The subsequent two functions are pop-up windows of varying dimensions. They are identical except for their dimensions and their names. (The 640 x 480 window is named window6; the other is simply named window.) The parenthetical URL (url) is a variable. If a pop-up window is needed on any HTML page that refers to this global JavaScript document, the address of the pop-up window will be inserted between the parentheses (popupwin- dow.html). How do the HTML pages make use of this global JavaScript document? Just as with global style sheets, they do it by referring to the .js file with a link: <script “”type=”text/javascript” src=”glam.js”></script> The link appears inside the <HEAD> of each HTML document that requires these scripts. <!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN” “http://www.w3.org/TR/1999/REC-html401-19991224/loose.dtd”> <html> <head> <link rel=”StyleSheet” href=”glam.css” type=”text/css” media=”screen”> <script “”type=”text/javascript” src=”glam.js”></script> <title>Jeffrey Zeldman Presents: My Glamorous Life</title> </head> <body onLoad=”preloadImages(); window.defaultStatus=’Jeffrey Zeldman Presents. ➥Entertainment, free graphics, and web design tips since 1995.’”> 323 Taking Your Talent to the Web 15 0732 CH11 4/24/01 11:23 AM Page 323 Notice that the <BODY> tag includes these two onLoad functions: preloadImages and window.defaultStatus. The first preloads the images as referenced in glam.js. The second is our old friend, the default status bar message—the first snippet of JavaScript we learned in this chapter. The two are combined in one onLoad declaration and separated by a semicolon. Simple. LEARNING MORE There is so much that JavaScript can do. This chapter barely hints at the possibilities, and some methods used in this chapter could be out of date by the time you read this book. With the arrival of full support for ECMAScript and the DOM, the dynamic possibilities for websites will expand exponentially. If you find, as some do, that you take naturally to JavaScript and want to learn more about the standardized version of JavaScript (ECMAScript) and the DOM: ■ The W3C offers the DOM at http://www.w3.org/DOM/ in all its baffling glory. ■ WebReference’s “Doc JavaScript” (http://www.webreference.com/ js/) offers many fine articles covering ECMAScript, JavaScript, and the DOM. ■ Peter-Paul Koch maintains a DOM mailing list (http://www.xs4all.nl/ ~ppk/js/list.html). ■ The Web Standards Project maintains links to the latest ECMAScript and DOM resources, beginning at http://www.webstandards.org/ resources.html. And A List Apart (http://www.alistapart.com/) offers the Eisenberg DOM series, an ongoing tutorial that includes: ■ Meet the DOM: http://www.alistapart.com/stories/dom/ ■ DOM Design Tricks: http://www.alistapart.com/stories/dom2/ ■ DOM Design Tricks 2: http://www.alistapart.com/stories/domtricks2/ ■ DOM Design Tricks 3: http://www.alistapart.com/stories/domtricks3/ 324 HOW: The Joy of JavaScript: Learning More 15 0732 CH11 4/24/01 11:23 AM Page 324 Whether you tackle this advanced stuff now or crawl off to recover from reading this chapter, be proud of yourself. You have faced your fears and at least looked at the part of web design that most designers find confus- ing and unintuitive. This is mainly because, compared to Photoshop and <p> paragraph tags, JavaScript is confusing and unintuitive. But with practice and experience, it will get easier. And when browsers do a better job of complying with ECMAScript and the W3C DOM, it will get easier still. The programming will not be easy, but you or your development team will take comfort in the fact that you only have to code your site one way to work in all browsers. There is just a little more to learn before you can consider yourself a full- fledged (or at least a fledgling) web designer. And by a strange coincidence, what you still don’t know is covered in the very next chapter. Let’s go for it, shall we? 325 Taking Your Talent to the Web 15 0732 CH11 4/24/01 11:23 AM Page 325 15 0732 CH11 4/24/01 11:23 AM Page 326 chapter 12 Beyond Text/Pictures ON FIRST DISCOVERING THAT THE WEB IS NOT PRINT, many designers see only the drawbacks: poor typographic resolution; a limited pool of installed user fonts; bandwidth bugaboos; the need to compensate for browser, platform, and hardware differences; and the awkwardness of trying to read a com- puter screen in the bathroom. As we start to become genuine web designers, though, most of us see more advantages than disadvantages in the Web’s distinctive differences from print. For example, instant worldwide distribution looks pretty darned good after wrestling with print shops and mail houses. The longer we work at it, the more we marvel at the Web’s ability to provide universal access across seemingly unbridgeable gaps of technol- ogy, nationality, economic and political systems, and physical ability or disability. As these barriers are crossed, the human spirit becomes less isolated, sus- picion and intolerance begin to fade, and we learn to appreciate each other’s differences instead of fearing them. These benefits will greatly increase if the whole world gets to come along for the ride. They will greatly diminish if too many humans get left behind. 16 0732 CH12 4/24/01 11:24 AM Page 327 This, the substance of the vision of the founders of the Web, should be enough. But there is more. In particular, there are the two profound differ- ences between the Web and print that we’ll discuss in this chapter: 1. The ability to develop not simply static pages, but full-fledged, dynamic experiences 2. The visual, sonic, and interactive possibilities inherent in rich media, whether it is delivered through emerging web standards or popular plug-in technologies These two unique strengths of the Web have tremendous implications for business and for art. Each has played a huge part in popularizing the medium. Each brims with powerful potential that designers and develop- ers have barely begun to tap. Each also has the potential to be abused. 328 HOW: Beyond Text/Pictures Figure 12.1 Nicola Stumpo’s “Destroy Everything” is a noncom- mercial, nonnarrative Flash site that eats your screen alive. Stumpo’s emotions are probably inexpressible in any medium outside Macromedia Flash (http://www. abnormalbehaviorchild. com/). 16 0732 CH12 4/24/01 11:24 AM Page 328 PRELUDE TO THE AFTERNOON OF DYNAMIC WEBSITES In Chapter 11, “The Joy of JavaScript,” we saw how JavaScript and its big brother, the Document Object Model (DOM), facilitate interactivity that printed media can only dream about. In the pages that follow, we’ll look at additional and powerful ways of making the Web more interactive. Dynamic sites enable web users to locate information, store phone num- bers in a shared contact database, buy holiday gifts without braving crowded shopping centers, or view “adult” material without shame until the baby-sitter barges in. In this chapter, we will see how web agencies use server-side applications to build sites that let users do things. We’ll look at where the web designer fits in and how server-side applications help us manage immense content sites or change text and appearance in response to user actions. We’ll also discuss how small shops and freelancers can get in on the action even if they don’t have casts of thousands and budgets of millions at their dis- posal. We’ll also see how technologies like Java can compensate for “missing pieces” in our visitors’ browser setups or unleash full-fledged software pro- grams that run right in the browser. And we’ll explore Java’s potential beyond the desktop. 329 Taking Your Talent to the Web Figure 12.2 Here is a tranquil moment outside the Eiffel Tower, captured in all its panoramic, Sensurround glory courtesy of Apple’s QuickTime VR—part of the QuickTime plug-in. Print cannot do this (http:// www.apple.com/). 16 0732 CH12 4/24/01 11:24 AM Page 329 You Can Never Be Too Rich Media After all that, we’ll examine emerging “multimedia” web standards that are almost ready for prime time and take a peek and a poke at plug-in tech- nologies that can radically enhance your sites—if used with respect for the realities of average web users. These technologies are not for every site, but, when appropriate, they can enhance the web user’s experience tremendously. Used poorly, of course, they lead to less satisfying experiences. We will explore all these tech- nologies and consider what causes both kinds of experiences. Knowing you as we do, we’ll start with the drier, more technical stuff because if we saved it for later, you’d never read it. THE FORM OF FUNCTION: DYNAMIC TECHNOLOGIES Think back to our earlier discussion of Perl versus JavaScript in Chapter 2, “Designing for the Medium.” As far as the Web is concerned, Perl is most often used in server-side transactions, such as the processing of a visitor- submitted mail form. You might remember that a server-side technology is one in which the computing process takes place on the web server (hence the name) rather than the end-user’s PC. With Perl, number-crunching tasks fall to the web server, while the visitor’s computer sits idly, waiting. We contrasted Perl with JavaScript, whose actions take place in the browser. With JavaScript, the end-user’s computer (the “client,” in geek parlance) does the heavy lifting. JavaScript is a client-side technology. Nat- urally, the dynamic technologies we’re about to consider do some work on the client side and some on the server side. After all, the two sides are con- tinually interacting. If the two sides, client and server, were not continu- ally interacting, you would not have web transactions; you would just have machines sitting around doing nothing, like Teamsters. But though they necessarily move from one realm to the other, most of the dynamic technologies we’re about to discuss do the bulk of their work either on the server or on the user’s desktop. Sometimes where they work 330 HOW: Beyond Text/Pictures: The Form of Function 16 0732 CH12 4/24/01 11:24 AM Page 330 [...]... information architects do as they envision and structure the site’s transactions The data can be stored in an open source MySQL database, or in similar programs from Microsoft, Oracle, and other companies As each visitor hits the site and begins to take actions, the middleware that lies between the visitor and the back-end database begins to do its thing It is the job of the middleware to process each... “Preferences” at Daniel Bogan’s Waferbaby Choose a look, and the site changes Though this might appear to be the brainchild of a programmer, Bogan is actually an animator-illustrator If he can do it, you can do it (http:// www.waferbaby.com/) In “Brainstorm,” readers respond to a provocative question on the site by typing their answers in a form Instantly, these answers appear on the page, in reverse... meetings and don’t rush to argue Talk, listen, and learn The work process is but a variation on what you already do You might take the comp no further than Photoshop; the developers will try to emulate it in, say, Cold Fusion, and show you the result You might ask them to revise their code to bring the design up to your spec; they might ask you to revisit the design to accommodate limitations in the software... response to the visitor’s desires 16 0732 CH12 4/24/01 11:24 AM Page 333 Taking Your Talent to the Web Paradoxically, your job will not change that much from what we’ve described earlier in this book You are still creating the part of the site that the visitor sees You design it as you would any other web project In a way, it’s like designing a magazine’s table of contents page You create the master... via frames, or your newly acquired mastery of DHTML Low bandwidth, large areas of flat, web-safe color, reasonably sized web fonts: This is the terrain you must plow; these are the fields you must harvest 16 0732 CH12 4/24/01 11:24 AM Page 335 Taking Your Talent to the Web Some web designers understand this as part of the discipline of the craft and strive to bring beauty, elegance, and utility to their... achieve the same result with light, clean, structural markup and a single declaration in a global style sheet By doing the work in CSS, you save processor cycles and bandwidth; and when it comes time to update the design, you can do it yourself in the style sheet instead of pestering the programmers to change their scripts Naturally, you will have to test to make sure that the middleware your company has... query-related entries from a huge database, determines which links are probably most relevant, and pours the results into a preexisting HTML template Who made the software? Programmers How does data get into the database? More software: specifically, a search engine spider, so named because it crawls around the Web indexing the content and location of individual web pages Where does the designer fit in? The. .. support for web standards and as web designers and developers begin using these standards instead of whining about them or pleading ignorance, the dynamic tools will likely improve in this regard Serving the project As you might expect, database-driven sites, built with templates, are usually not the place to show off your deep Photoshop layering skills, your ability to bring complex layouts to life via... Some versatile technologies work both sides of the street Java, for instance, is frequently used on the client side, as a downloadable applet But it also performs many server-side jobs You’ll hear developers and systems administrators talk about Java servlets, which are miniature Java applications that run the Apache server’s mod_jserv component Or you might host a site on Jigsaw, a W3C server that’s written... in the browser When the reader is happy with the color scheme and typography, it is stored as a JavaScript cookie on her hard drive The site will use her chosen color scheme and fonts until she decides to change it 16 0732 CH12 4/24/01 11:24 AM Page 337 Taking Your Talent to the Web 337 Both “Brainstorm” and “Preferences” are made possible by a few lines of code in PHP, a JavaScript cookie, and a MySQL . 12.3 User-selectable “Preferences” at Daniel Bogan’s Waferbaby. Choose a look, and the site changes. Though this might appear to be the brainchild of a pro- grammer, Bogan is actually an animator-illustrator. If he can do. the two teams are talking to each other so that design and content work together.) The content is stored and indexed in vast, humming “back-end” databases, 331 Taking Your Talent to the Web 16. can be stored in an open source MySQL database, or in similar programs from Microsoft, Oracle, and other companies. As each visitor hits the site and begins to take actions, the middleware that