Getting Elements by Name

So far in this chapter, I've used navigation methods such as nextSibling and nextChild to move through XML documents. However, you can also get individual elements by searching for them by name. Here's an example. In this case, I'll use the document object's getElementsByTagName method to return a node list object holding all elements of a given name. In particular, I'm searching for <FIRST_NAME> and <LAST_NAME> elements, so I get lists of those elements like this:

 <HTML>      <HEAD>          <TITLE>              Reading XML element values          </TITLE>          <SCRIPT LANGUAGE="JavaScript">               function loadDocument()               {                   var xmldoc, listNodesFirstName, listNodesLastName                   xmldoc = new ActiveXObject("Microsoft.XMLDOM")                   xmldoc.load("ch07_01.xml")  listNodesFirstName =xmldoc.getElementsByTagName("FIRST_NAME")   listNodesLastName = xmldoc.getElementsByTagName("LAST_NAME")<HTML>  .     .     .

Like all node lists, the listNodesFirstName and listNodesLastName node lists are indexed by number starting at 0, so the third element in these lists is element number 2, which you refer to as listNodesLastName.item(2) . That means I can find the first and last name of the third person like this in the whole listing (recall that I actually need the first child of the <FIRST_NAME> and <LAST_NAME> nodes, which is the text node inside those elements that holds the person's name, so I use the firstChild method here):

Listing ch07_04.html

 <HTML>     <HEAD>          <TITLE>              Reading XML element values          </TITLE>          <SCRIPT LANGUAGE="JavaScript">               function loadDocument()               {                   var xmldoc, listNodesFirstName, listNodesLastName                   xmldoc = new ActiveXObject("Microsoft.XMLDOM")                   xmldoc.load("ch07_01.xml")                   listNodesFirstName = xmldoc.getElementsByTagName("FIRST_NAME")                   listNodesLastName = xmldoc.getElementsByTagName("LAST_NAME")                   outputText = "Third name: " +  listNodesFirstName.item(2).firstChild.nodeValue + ' '   + listNodesLastName.item(2).firstChild.nodeValue  messageDIV.innerHTML=outputText              }          </SCRIPT>     </HEAD>     <BODY>         <CENTER>             <H1>                 Reading XML element values             </H1>             <INPUT TYPE="BUTTON" VALUE="Get the name of the third person"                 ONCLICK="loadDocument()">             <P>             <DIV ID="messageDIV"></DIV>         </CENTER>     </BODY> </HTML>

We've made some progress here. We've been able to read in an XML document in various ways, and we've been able to access specific elements in the document. I'll move on to the next step now: accessing not just an element's text content, but also the element's attributes.