제7장. Parser & DOM

DOM 트리 운행 예제 : 예제 1 (p.211~213)

conversion.js

function convert(fm, xmldoc)
{
   var fname = fm.fname.value,
         output = fm.output,
       rate = fm.rate.value;
   output.value = "";

   var doc = parse(fname,xmldoc),
        top = doc.documentElement;
   searchPrice(top,output,rate);
}

function parse(uri,xmldoc)
{
   xmldoc.async = false;
   xmldoc.load(uri);

   if (xmldoc.parseError.errorCode != 0)
        alert(xmldoc.parseError.reason);
   return xmldoc;
}

function getText(node)
{
   return node.firstChild.data;
}

function searchPrice(node,output,rate)
{
   if(node.nodeType == 1)
   {
      if(node.nodeName == "name") // 미완성
         output.value += getText(node) + " : ";
      if(node.nodeName == "price")
       output.value += (getText(node)*rate)+ "\r";

      var children, i;
      children = node.childNodes;
      for (i=0; i<children.length; i++)
         searchPrice(children.item(i), output, rate);
   }
}

상태관리 : 예제 2 [p.221] 상태정보를 유지하면서 트리 운행

function walkProduct(node,output,rate)
{
if(node.nodeType==1 &&
                node.nodeName=="product")
{
   var name, price, children, i;
   children = node.childNodes;
     for (i=0; i<children.length; i++)
     {
        var child = children.item(i);
        if(child.nodeType == 1)
        {
           if(child.nodeName == "price")
               price = getText(child)*rate;
           else if(child.nodeName == "name")
               name = getText(child);
        }
     }
     output.value += name + ":" + price + "\r";
}
}

속성(attributes)의 처리 : 예제 3 [리스트 7.3 p.226]

속성을 갖는 변환 프로그램, 예) <price currency=”usd”>499.0</price>

var USD = 1, CAD = 2; // US, Canada function getCurrencyCode(currency) { if (currency == "usd") return USD; else if (currency == "cad") return CAD; else return -1; } function convert(fm, xmldoc) { var pfile = fm.prices.value, // new rfile = fm.rates.value, // new output = fm.output, rates = new Array(3); // new output.value = ""; var doc = parse(rfile,xmldoc), // new top = doc.documentElement; // new searchRate(top,rates); // new doc = parse(pfile,xmldoc), top = doc.documentElement; walkNode(top,output,rates); } function parse(uri,xmldoc) // same	function searchRate(node,rates) // new { if(node.nodeType == 1) { if(node.nodeName == "rate") walkRate(node,rates); var children, i; children = node.childNodes; for (i=0; i<children.length; i++) searchRate(children.item(i),rates); } } function walkRate(node,rates) { if (node.attributes != null) { var attr = node.attributes.getNamedItem("currency"); var currency = getCurrencyCode(attr.value); rate = node.attributes.getNamedItem("rate"); if (currency != -1) rates[currency] = rate.value; } }
function walkNode(node,output,rates) { // almost same if(node.nodeType == 1) { if(node.nodeName == "product") walkProduct(node,output,rates); // else { . . . // 생략 for (i=0; i<children.length; i++) walkNode(children.item(i), output, rates); } } } function walkProduct(node,output,rates) { //almost same if(node.nodeType==1 && node.nodeName=="product") { . . . // 생략 for (i=0; i<children.length; i++) { var child = children.item(i); if(child.nodeType == 1) { if(child.nodeName == "price") price = walkPrice(child,rates); else if(child.nodeName == "name") name = getText(child); } } output.value += name + ": " + price + "\r"; } }
	function walkPrice(node,rates) { // similar to walkRate, 교과서 오류 if (node.attributes != null) { var attr = node.attributes.getNamedItem("currency"); var currency = getCurrencyCode(attr.value); if (currency != -1) return getText(node)*rates[currency]; } } function getText(node) // same

오류 [p.232]

XML 파서는 엄격하다.
오류 메세지 예제

xmldoc.loadXML('<p>Send comments and suggestions to
<url protocol="mailto">sblim@sookmyuing.ac.kr.</p>');
if (xmldoc.parseError) alert(xmldoc.parseError.reason);

xmldoc.loadXML('<p>Send comments and suggestions to
<url protocol="mailto>sblim@sookmyuing.ac.kr.</url></p>');
if (xmldoc.parseError) alert(xmldoc.parseError.reason);

xmldoc.loadXML('<xsl:stylesheet   xmlns:xsl="http://www.w3.org/TR/WD-xsl">
                                          <xml:template match="p"> <P><xsl:apply-template/> </xsl:template>
                                   </xsl:stylesheet>');
if (xmldoc.parseError) alert(xmldoc.parseError.reason);

DOM과 Java 응용

리스트 7.9 [p.235~p.237]
주요 차이점 : getPropertyName()
- Javascript : if (node.nodeName == "product")
- Java : if (node.getNodeName().equals("product"))
타입캐스팅
- Node child = node.getFirstChild();
  Text text = (Text)child;
  return text.getData();
파서 호출 방법
- protected static Document parse(String uri) throws Exception
  {
      NonvalidationDOMParser parser = new NonValidatingDOMParser();
      parser.parse(uri);
      return parser.getDocument();
  }

브라우저 응용 프로그램 : 리스트 7.12 [p.240]

function convert(fm, xmldoc)
{
   var output = fm.output,
         rate = fm.rate.value;

   output.value = "";
   var top = xmldoc.documentElement;
   searchPrice(top,output,rate);
}

function searchPrice(node,output,rate)
{
   if(node.nodeType == 1)
   {
      if(node.nodeName == "price")
         output.value += (getText(node)*rate)+ "\r";
      var children, i;
      children = node.childNodes;
      for (i=0; i<children.length; i++)
         searchPrice(children.item(i), output, rate);
   }
}

function getText(node)
{
   if(node.nodeType == 1)
   {
      var text = "", children, i;
      children = node.childNodes;
      for (i=0; i<children.length; i++)
         if (children.item(i).nodeType == 3)
              text += children.item(i).data;
      return text
   }
   else
      return "";
}