922 Part III . Document Objects Reference Syntax Accessing XML element object properties or methods: (IE5+) [window.]document.all.elementID.property | method([parameters]) About this object The XML element object is the primary container of an XML data island within an HTML page. If your scripts intend to traverse the node hierarchy within the element, or simply access properties of nested elements, then you should assign an identifier to the IDattribute of the XML element. For example, if the XML data contains results from a database query for music recordings that match some user- entered criteria, each returned record might be denoted as a RECORDING element as follows: …elements with details… …elements with details… …elements with details… Your script can now obtain an array of references to RECORDING elements as follows: var recs = document.getElementById( results ).getElementsByTagName( RECORDING ) While it is also true that there is no known HTML element with the tag name RECORDING (which enables you to use document.getElementsByTagName ( RECORDING )), the unpredictability of XML data element names is reason enough to limit the scope of the getElementsByTagName() method to the XML data island. Interestingly, the W3C DOM Level 2 does not define an XML element object within the HTML section. You cannot simply embed an XML document inside an HTML document: The standards clearly indicate that a document can be one or the other, but not both. While the NN6 DOM can recognize custom elements, the browser understandably gets confused when custom elements have tag names that already belong to the HTML DTD. Therefore, I do not recommend attempting to embed custom elements into an HTML document for NN6 unless it some day implements a mechanism similar to IE s XML data islands. Note IE5/Macintosh does not support XML data islands. In case you need affordable webhost to host your website, our recommendation is ecommerce web host services.
921Chapter 33 .XML Objects Table 33-1 Properties and Methods for XML Element Reading Property or Method Description Node.nodeValue Data of a text node Node.nodeType Which node type Node.parentNode Reference to parent node Node.childNodes Array of child nodes Node.firstChild First of all child nodes Node.lastChild Last of all child nodes Node.previousSibling Previous node at same level Node.nextSibling Next node at same level Element.parentNode Reference to parent node Element.childNodes Array of child nodes Element.firstChild First of all child nodes Element.lastChild Last of all child nodes Element.previousSibling Previous node at same level Element.nextSibling Next node at same level Element.tagName Tag name Element.getAttribute(name) Retrieves attribute (Attr) object Element.getElementsByTagName(name) Array of nested, named elements Attr.name Name part of attribute object s name/ value pair Attr.value Value part of attribute object s name/ value pair XML Element Object For HTML element properties, methods, and event handlers, see Chapter 15. Properties Methods Event Handlers src XMLDocument XML Go visit our java server pages services for a reliable, lowcost webhost to satisfy all your needs.
920 Part III . Document Objects Reference Chapter 15. Note describe an individual s contact information with one set of elements, while another application uses a completely different approach to element names, element nesting, and their sequence. Fortunately, most, if not all, scripting you do on XML data is on data served up by your own applications. Therefore, you know what the structure of the data is or you know enough of it to let your scripts access the data. The discussion of the W3C DOM in Chapter 14 should serve as a good introduc tion to the way you need to think about elements and their content. All relevant properties and methods are listed among the items shared by all elements in Microsoft has created a separate document object model exclusively for XML documents. To distinguish between the DOMs for XML and HTML documents, Microsoft calls the former the XML DOM and the latter the DHTML DOM. Specifications for the two DOMs overlap in some terminology, but the two models are not interchangeable. Read more about the Microsoft XML DOM at http:// msdn.microsoft.com. An XML data island is a hierarchy of nodes. Typically, the outermost nodes are elements. Some elements have attributes, each of which is a typical name/value pair. Some elements have data that goes between the start and end tags of the element (such data is a text node nested inside the element node). And some elements can have both attributes and data. When an XML island contains the equivalent of multiple database records, an element container whose tag name is the same as each of the other records surrounds each record. Thus, the getElementsByTagName() method frequently accesses a collection of like- named elements. Once you have a reference to an element node, you can reference that ele ment s attributes as properties; however, a more formal access route is via the getAttribute() method of the element. If the element has data between its start and end tags, you can access that data from the element s reference by calling the firstChild.data property (although you may want to verify that the element has a child node of the text type before committing to retrieving the data). Of course, your specific approach to XML elements and their data varies with what you intend to script with the data. For example, you may wish to do nothing more with scripting than enable a different style sheet for the data based on a user choice. The evolving XSL (eXtensible Stylesheet Language) standard is a kind of (non-JavaScript) scripting language for transforming raw XML data into a variety of presentations. But you can still use JavaScript to connect user-interface elements that control which of several style sheets renders the data. Or, as demonstrated in Chapters 52 and 57, you may wish to use JavaScript for more explicit control over the data and its rendering, taking advantage of JavaScript sorting and data manipu lation facilities along the way. Table 33-1 is a summary of W3C DOM Core objects, properties, and methods that you are most likely to use in extracting data from XML elements. You can find details of all of these items in Chapter 15. You want to have a cheap webhost for your apache application, then check apache web hosting services.
XML Objects 33 CHAPTER XML (eXtensible Markup Language) is an undeniably hot topic in the Internet world. Not only has the W3C organization formed multiple working groups and recommendations for XML and its offshoots, but the W3C DOM recommendation also has XML in mind when it comes to defining how elements, attributes, and data of any kind not just the HTML vocabulary are exposed to browsers as an object model. Most of the arcana of the W3C DOM Core specification especially the structure based on the node are in direct response to the XML possibilities of documents that are beginning to travel the Internet. While XML documents can stand alone as containers of structured data in both IE5+ and NN6, the Windows version of IE5+ permits XML data to be embedded as islands in an HTML document. Such islands are encased in an XML element an IE-specific extension of HTML. It s important to distinguish between the XML element the element generated in a document by the IE-specific tag set and a generic XML element that is a part of the XML data island. Generic XML elements have tag names that are meaningful to a data application, and they are usually defined by a separate Document Type Declaration (DTD) that contains a formal specification of the element names, their attributes (if any) and the nature of the data they can contain. Out of necessity, this book assumes that you are already familiar with XML such that your server-based applications serve up XML data exclusively, embed XML islands into HTML documents, or convert database data into XML. The focus of this chapter, and an extended application example of Chapter 57, is how to access custom elements that reside inside an IE XML element. Elements and Nodes Once you leave the specialized DOM vocabulary of HTML elements, the world can appear rather primitive a highly granular world of node hierarchies, elements, element attri butes, and node data. This granularity is a necessity in an environment in which the elements are far from generic and the structure of data in a document does not have to follow a format handed down from above. One Web application can …. In This Chapter Treating XML elements as objects Creating IE XML data islands Accessing XML element attributes …. We recommend you use shared web hosting services, because many users agree that it is cheap, reliable and customer-satisfying webhost.
917Chapter 32 .Embedded Objects The Odd Case of the PARAM Element HTML pages pass parameters to Java applets, plug-ins, and ActiveX controls by way of PARAM elements that are nested inside APPLET, EMBED, and OBJECT elements. Although a PARAM element object is defined by the W3C DOM Level 2 specification, it does not show up on some browsers radar when you try to reference the PARAM element by itself. Even assigning an ID to a PARAM element or using document.getElementsByTagName( PARAM ) fail to allow references to access an individual PARAM element object. At most, you can retrieve the innerHTML property of the surrounding element. But even here, the values returned may not necessarily be precisely the HTML you specify in the document. In practice, this limitation is not particularly important. For one thing, even if you could access the PARAM elements of an embedded object or program, attempts to modify the values would be wasted: Those values are read at load time only. Secondly, a well-designed plug-in, applet, or ActiveX control will provide its own properties or methods to retrieve the current settings of whatever properties are initialized via the PARAM elements. … PARAM We would like to recommend you tested and proved virtual web hosting services, which you will surely find to be of great quality.
916 Part III . Document Objects Reference pluginspage Value: String Read-Only Compatibility NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 . IE5 . IE5.5 . The pluginspage property represents the PLUGINSPAGE attribute of the EMBED element. This attribute is a URL that gets applied to a link in the browser if the plug-in associated with the external file s MIME type cannot be found on the client. Related Items: None. src Value: String Read/Write NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The src property represents the SRCattribute of the EMBED element. This attribute points to the external file that is to be loaded into the browser via the associated plug-in. Scripts can assign a new URL string to this property to load a different file into the current plug-in. Related Items: None. units Value: String Read-Only NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The units property returns the unit of measure assigned with the length value of the height and widthproperties. In IE4, this property returned only px. The property does not appear to be connected in IE5.5, so it is probably deprecated in IE. Related Items: height, width properties. EMBED.units We recommend you use shared web hosting services, because many users agree that it is cheap, reliable and customer-satisfying webhost.
915Chapter 32 .Embedded Objects heightwidth Value: Integer Read/Write NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The height and widthproperties represent the HEIGHTand WIDTH attributes of the EMBED element. While these values should be set via attributes in the tag, these properties can adjust the size of the element after the fact in IE5+. Related Items: None. hidden Value: Boolean Read/Write NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The hidden property represents the HIDDENattribute of the EMBED element. When an EMBED element is hidden, neither controller nor the content is shown. Application of this element in modern browsers should use style sheets to hide and show the element. Related Items: style.visibility property. name Value: String Read-Only NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The name property represents the NAMEattribute of the EMBED element. The better form is to assign an ID to the EMBED element and use accepted reference syntax for element ids. Related Items: None. EMBED.name From our experience, we are can tell you that you can find a reliable and cheap webhost service at Java Web Hosting services.
914 Part III . Document Objects Reference Syntax Accessing EMBED element object properties or methods: (IE4+) [window.]document.all.objectID.property | method([parameters]) (IE5+/NN6) [window.]document.getElementById( objectID ).property | method([parameters]) About this object An EMBED element is a carryover from the early browser days. Although never adopted by the W3C HTML standard, the EMBED element has been used in NN and IE as a way to embed non-native content (for example, sounds, video clips, and custom MIME types for plug-ins, such as Shockwave) into a page. What gets embed ded into the page is the controller or viewer for whatever kind of data the EMBED element points to (via the SRC attribute). The EMBED element is far less sophisticated than the OBJECT element, but current browsers continue to support it. If you have been using the EMBED element in previous applications, it may be a good idea to start gravitating toward the OBJECT element. For backward compatibility purposes, nesting an EMBED element inside an OBJECT element is not uncommon, both of which attempt to load the same content and plug-in. Browsers that know about the OBJECT element will load the content that way; older browsers will use the EMBED element and its attributes and parameters. Because an EMBED element loads a plug-in (including ActiveX control types of plug-ins in IE/Windows), you can reference the plug-in s properties and methods through the EMBED object s reference. Properties align Value: String Read/Write NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The align property controls either the horizontal or vertical alignment of the element with regard to surrounding content. String values of leftor rightcause the object rectangle to cling to the left or right edges of its next outermost positioning context. String values of absbottom, absmiddle, baseline, bottom, middle, texttop, or top influence the vertical alignment with respect to adjacent text, with the same kind of results as corresponding values of the style.verticalAlign property. Related Items: style.verticalAlign property. EMBED.align Visit our web design programs services for an affordable and reliable webhost to suit all your needs.
913Chapter 32 .Embedded Objects type Value: String Read-Only NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The type property represents the TYPEattribute of the OBJECT element, which, in theory anyway, is intended to warn the browser about the MIME type of data that is to be loaded into the object s process. I say in theory because the HTML 4.0 specification links the TYPE attribute to the DATA attribute, which points to the data to be loaded to support whatever program code is loaded via the CLASSIDor CODE attribute. But through IE5.5, there is no support for the DATAattribute. Related Items: codeType property. vspace See hspace. width See height. EMBED Element Object For HTML element properties, methods, and event handlers, see Chapter 15. Properties Methods Event Handlers align (Object methods) onLoad height onScroll hidden name pluginspage src units width (Object variables) EMBED We highly recommend you visit web and email hosting services if you need stable and cheap web hosting platform for your web applications.
912 Part III . Document Objects Reference attributes in the tag, these properties can adjust the size of the padding around the element after the fact in IE5+. Related Items: height, width properties. name Value: String Read-Only NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The name property represents the NAMEattribute of the OBJECT element. The better form is to assign an ID to the OBJECT element and use accepted reference syntax for element ids. Related Items: None. object Value: External Object Read-Only NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5 Compatibility . . The object property returns a reference to the object contained by the OBJECT element. This property is essential if the program running inside the OBJECT element has the same property or method names as the OBJECT element itself. For example, consider a Java applet loaded into the OBJECT element as follows: