檢查循環AS3中的XML父項

Question

是否可以檢查所有XML節點父項是否存在於某種循環中？比方說，我的線沿線的一個參考：

myXML.sectionOne.subSectionOne.subsubSectionFive.subsubsubSectionTwo.name 

什麼我發現是，不僅可能會在name節點不存在的，但任何數量的父節點的可能不存在的。所以我一直在堅持做的是沿着線的東西：

if(myXML.sectionOne != undefined) 
{ 
    if(myXML.sectionOne.subSectionOne != undefined) 
    { 
     if(myXML.sectionOne.subSectionOne.subsubSectionFive != undefined) 
     { 
      if(myXML.sectionOne.subSectionOne.subsubSectionFive.subsubsubSectionTwo != undefined) 
      { 
       if(myXML.sectionOne.subSectionOne.subsubSectionFive.subsubsubSectionTwo.name != undefined) 
       { 

       } 
      } 
     } 
    } 
} 

Answer 1

你可以寫一個遞歸函數來檢查每個節點的localName()：

var xml:XML = <root> 
<sectionOne> 
    <subSectionOne> 
     <subsubSectionFive> 
      <subsubsubSectionTwo> 
       <name>bam!</name> 
      </subsubsubSectionTwo> 
     </subsubSectionFive> 
    </subSectionOne> 
</sectionOne> 
</root>; 

trace(hasNodeByName(xml,"name")); 

function hasNodeByName(xml:XML,nodeName:String):Boolean{ 
    if(xml.localName() == nodeName) return true;//check root 
    for each(var node:XML in xml.*){//check each node on 1st level 
     if(node.localName() == nodeName) return true; 
     else if(node.length() > 0) return hasNodeByName(node,nodeName);//we need to go deeper! 
    } 
    return false; 
}