tài liệu javascript và dom

... TRONG JAVASCRIPT Các sự kiện cung cấp các tương tác với cửa sổ trình duyệt và tài liệu hiện hành đang được load trong trang web, các hành động của user khi nhập dữ liệu vào form và khi click vào ... Web</A> </BODY> </HTML> Mở và đóng các cửa sổ Sử dụng phương pháp open() và close() ta có thể điều khiển việc mở và đóng cửa sổ chứa tài liệu open (“URL” , “WindowName” , “featureList”) ... JavaScript ta phải tạo một instance cho đối tượng đó 6 Nhúng JavaScript vào trong tập tin HTML: Cú pháp: <SCRIPT LANGUAGE=”JavaScript”> JavaScript Program </SCRIPT> Thuộc tính của thẻ SCRIPT

Ngày tải lên: 23/08/2012, 10:31

... the cookie. // domain - String object containing the domain of the cookie to delete This MUST // be the same as the domain used to create the cookie, or null/omitted if // no domain was specified ... DeleteCookie (name,path,domain) { if (GetCookie(name)) { document.cookie = name + "=" + Trang 19((path) ? "; path=" + path : "") +((domain) ? "; domain=" + domain : "") ... cookie file whose domain parametermatches that of the current document Unless you expect the document to be replicated in another server within yourdomain, you can usually omit the domain parameter

Ngày tải lên: 10/12/2013, 15:15

... direct the URL to a JavaScript function The URL javascript:functionName()is a valid location parameter for the HREF attribute (and not just in the link object) Using the javascript:URL to call ... working with a link object in your scripts, the JavaScript object world begins to wrap around itself in a way Despite all the attributes that define a link, JavaScript regards a link as the same as ... onMouseOver=event handler, define an empty function and set the URL to that Trang 3empty JavaScript function (such as HREF=”javascript:doNothing()”).Starting with Navigator 3, you can also add a special

Ngày tải lên: 10/12/2013, 15:15

... filename, JavaScript scales the image to fit the dimensions defined by the <IMG>tag attributes or (if none are provided) by the dimensions of the first image file loaded into that object JavaScript ... plug-ins) produce animation that offers better speed control and the like In fact, swapping preloaded JavaScript image objects for some cartoon-like animations may actually be too fast You could build ... wants to replicate settings from an existing image object If you need to set these attributes with JavaScript writing a page on-the-fly, use the document.write()method to write the equivalent of

Ngày tải lên: 10/12/2013, 15:15

... ways in which JavaScript enables scripters to manipulate strings Much of the syntax you see in this chapter is identical to that of the Java programming language Because the scope of JavaScript ... created in JavaScript makes adding certain characters to strings difficult I’m talking primarily about adding quotes, apostrophes, carriage returns, and tab characters to strings Fortunately, JavaScript ... values, visualize every string value as an object with properties and methods like other JavaScript objects JavaScript defines one property and a slew of methods for any string value (and one extra

Ngày tải lên: 21/12/2013, 05:17

... accomplish a great deal with JavaScript by using simple arithmetic and a little bit of logic, leaving the heavy-duty math for those who love it. Creating random numbers The Math.random() method returns ... need random integers between 1 and 52; for dice, the range is 1 to 6 per die. To generate a random integer between zero and any top value, use the following formula: Math.round(Math.random() * ... in JavaScript browsers to plan spaceflight trajectories. But it also means that for everyday math, you need to be cognizant of floating-point errors that accrue in PC arithmetic. In Navigator, JavaScript

Ngày tải lên: 21/12/2013, 05:17

... ObjectPerhaps the most untapped power of JavaScript is its date and time handling Scripters passed over the Date object with good cause in the early days of JavaScript, because in earlier versions ... is perhaps the most difficult concept to grasp as you work with JavaScript date and time Whenever you program time and date in JavaScript for a public Web page, you must take the world view This ... come in If you leave the parameters empty, JavaScript takes that to mean you want today’s date and the current time to be assigned to that new Date object JavaScript isn’t any smarter, of course,

Ngày tải lên: 21/12/2013, 05:17

... ObjectAn array is the sole JavaScript data structure provided for storing and manipulating ordered collections of data But unlike some other programming languages, JavaScript’s arrays are very ... spreadsheet In JavaScript, arrays are limited to a table holding one column of data, with as many rows as needed to hold your data As you have seen in many chapters in Part III, a JavaScript-enabled ... Array Arrays are treated in JavaScript like objects, but the extent to which yourscripts can treat them as objects depends on whether you’re using the first version of JavaScript (in Navigator 2

Ngày tải lên: 21/12/2013, 05:17

... that power to JavaScript Most of the benefit of JavaScript regular expressions accrues to those who script their CGI programs with LiveWire on Enterprise Server 3 or later The JavaScript version ... “JvaScript”, “JavaScript”, and “JaaavaScript” but not “JovaScript” ? Zero or one time /Ja?vaScript/matches “JvaScript” or “JavaScript” but not “JaaavaScript” + One or more times /Ja+vaScript/matches “JavaScript” ... Trang 4Special charactersThe regular expression in JavaScript borrows most of its vocabulary from the Perlregular expression In a few instances, JavaScript offers alternatives to simplify thesyntax,

Ngày tải lên: 21/12/2013, 05:17

... possible in JavaScript. JavaScript control structures follow along the same lines of many programming languages, particularly with additions made in Navigator 4 and Internet Explorer 4 (for JavaScript ... to use labels to assist in script navigation ✦ ✦ ✦ ✦ 646 Part III ✦ JavaScript Object and Language Reference true result. JavaScript uses no “then” keyword (as some other languages do); the keyword ... the statements executed on a true condition are not required by JavaScript. What you see here, however, is a con- vention that most JavaScript scripters follow. As you write the code in your text

Ngày tải lên: 21/12/2013, 05:17

... ambiguity of JavaScript’s equality internal conversions, JavaScript 1.2 in Navigator 4 introduces a different way of evaluating equality For all scripts encapsulated inside a <SCRIPT LANGUAGE=”JavaScript1.2”></SCRIPT>tag ... objects, need to be dealt with Therefore, prior to JavaScript 1.2, the rules of comparison are as shown in Table 32-3 Table 32-3 Equality Comparisons for JavaScript 1.0 and 1.1 Operand A Operand B Internal ... For all versions of JavaScript before 1.2, when your script tries to compare string values consisting of numerals and real numbers (for example, “123” == 123 or “123” != 123), JavaScript anticipates

Ngày tải lên: 21/12/2013, 05:17

... Trang 1The Event ObjectPrior to Navigator 4, user and system actions — events — were captured predominantly by event handlers defined as attributes inside HTML tags For instance, when a user clicked ... onClick=event handler in the tag That handler might invoke a separate function or perform some inline JavaScript script Even so, the events themselves were rather dumb: Either an event occurred or it ... program knows what and where on the screen the event is Event handlers Fortunately for scripters, the JavaScript language and document object model shield us from the dirty work of monitoring events

Ngày tải lên: 21/12/2013, 05:17

... FirstJavaScript Script In this chapter, you set up a productive script- writing and previewing environment on your computer — and then write a simple script whose results you will see in your JavaScript-compatible ... learning JavaScript, you may be better off using a simple text editor rather than a high-powered word processor with HTML extensions Choosing a text editor For the purposes of learning JavaScript ... for scripters, such as optional line numbers (which help in debugging JavaScript) In Chapter 46, I describe a Windows-based JavaScript authoring tool named Infuse 2.0 by Acadia Software This product

Ngày tải lên: 17/01/2014, 08:20

... is, get functions doing something) via three routes: JavaScript object event handlers; javaScript statements; and HREF=attributes pointing to a javascript:URL Trang 10Because you’ve seen dozens ... and client-side image map areas A JavaScript-enabled browser has a special built-in URL pseudo-protocol — javascript:— that lets the HREFattribute point to a JavaScript function ormethod, rather ... avoidusing JavaScript keywords (including the reserved words listed in Appendix B) andany global variable name defined elsewhere in your script (see more about globalvariables in following sections) JavaScript

Ngày tải lên: 17/01/2014, 08:20

... additional evaluation with the eval() function, the script invokes JavaScript to see if one more level of evaluation is needed If JavaScript finds that the evaluation of that string is a valid object ... comments and defining variables — statements used a lot in JavaScript Trang 9/* */ Comments are statements that are ignored by the JavaScript interpreter (or server-side compiler) but allow authors ... comments, particularly as you create a script JavaScript offers two styles of comments One style consists of two forward slashes (no spaces between them) JavaScript ignores any characters to the right

Ngày tải lên: 17/01/2014, 08:20

... client-side scripting purposes or for input into a server-based CGI or database, you should use JavaScript on the client to handle validation of the user’s entry Even for a form connected to a ... more efficient from bandwidth, server load, and execution speed perspectives to let client-side JavaScript get the data straight before your server program deals with it Real-time versus Batch ... points for more specific filters of your own design Some of these functions are put to use in the JavaScript application in Chapter 48 isEmpty() The first function, shown in Listing 37-1, checks

Ngày tải lên: 17/01/2014, 08:20

... seen with JavaScript, but I’ll try to be gentle Java building blocks classes One part of Java that closely resembles JavaScript is that Java programming deals with objects, much the way JavaScript ... Java applet “properties” The Java equivalents of JavaScript object properties are called public instance variables These variables are akin to JavaScript global variables If you have access to ... otherwise be JavaScript code that is open to any visitor’s view For example, if you want to deliver a small data collection lookup with a document, but don’t want the array of data visible in the JavaScript

Ngày tải lên: 17/01/2014, 08:20

... an alternate syntax that follows the dot syntax model of JavaScript Its style type is “text/javascript”, as follows: <STYLE TYPE=”text/javascript”> tags.H1.color=”red” </STYLE> Within ... Explorer 4 does not recognize the “text/javascript” style type, nor the JavaScript-like syntax within a <STYLE>tag set Moreover, while Netscape’s JavaScript objects used in <STYLE>tags ... the map puzzle game demonstrated in cross-platform format in Chapter 41 JavaScript Styles As with Cascading Style Sheets, JavaScript Style Sheets define layout characteristics for the content of

Ngày tải lên: 17/01/2014, 08:20

... that all scriptable browsers accept is the JavaScript language, as in <SCRIPT LANGUAGE=”JavaScript”> Other possibilities include later versions of JavaScript (version numbers are part of the ... include the ending tag for the script Lines of JavaScript code go between the two tags: <SCRIPT LANGUAGE=”JavaScript”> one or more lines of JavaScript code here </SCRIPT> If you forget ... eyes JavaScript Statements Every line of code that sits between a <SCRIPT>and </SCRIPT>tag is a JavaScript statement To be compatible with habits of experienced programmers, JavaScript

Ngày tải lên: 24/01/2014, 09:20

... right type JavaScript tries its best to perform internal conversions to head off such problems, but JavaScript cannot read your mind If your intentions are different from the way JavaScript treats ... checkbox (the fact of whether it is checked or not) is a value In JavaScript, a value can be one of several types Table 6-1 lists JavaScript’s formal data types, with examples of the values you ... in JavaScript, but one will cover you properly in all cases Use the varkeyword, followed by the name you want to give that variable Therefore, to declare a new variable called myAge, the JavaScript

Ngày tải lên: 24/01/2014, 09:20