reading XML attributes in javascript

Question

Guess it's a simple question for a javascript guru, but i'm learning and got a problem I can't guess out.

I'm interested in reading an XML file using javascript. Here is an example of the XML file:

<object name='obj1'>
   <attribute name='att1' value='val1'/>
   <attribute name='att2' value='val2'/>
   <attribute name='attN' value='valN'/>
   <subobject name='sub1'>
          <attribute name='satt1' value='sval1'/>
          <attribute name='satt2' value='sval2'/>
          <attribute name='sattN' value='svalN'/>
   </subobject>
   <subobject name='subn'>
          <attribute name='snatt1' value='snval1'/>
          <attribute name='snatt2' value='snval2'/>
          <attribute name='snattN' value='snvalN'/>
   </subobject>
</object>

As you can see, I have N objects. Each object has global attributes, and may have 0...M subobjects with their attributes.

Problem is, applying this (my) code to parse ob1 attributes, I also get all subobject attributes:

if (window.XMLHttpRequest) {    
    var xmlhttp=new XMLHttpRequest();
    xmlhttp.open("GET",URL,false);  
    xmlhttp.send();

    var xmlDoc=xmlhttp.responseXML;

    var objList = xmlDoc.getElementsByTagName("object");
    var attrList = objList[0].getElementsByTagName("attribute"); // Got ALL attributes here
}

In that code (no error test for simplicity), my attrList object gets both obj1 and all subobject attributes.

How can I rewrite the code to get only att1...attN?!?!

Thanks in advance!

hugomg · Accepted Answer · 2013-03-11 01:38:33Z

3

In, this case, since the attribute elements you are looking for are direct children of the object element, a simple thing you can do is iterate through the child elements of the object element by hand:

var obj = objList[0]
var childNodes = obj.childNodes
for(var i=0; i<childNodes.length; i++){
    var child = childNodes[i];
    if(child.nodeType == 1 && child.nodeName == 'attribute'){
        do_something(child);
    }
}

For information on these and other DOM methods, I recommend checking out the documentation over on MDN.

answered Mar 11, 2013 at 1:38

hugomg

70.4k30 gold badges168 silver badges257 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ishmar Over a year ago

LOL. Saw something like that before, but since childNodes.length is bigger than N, I thought it was wrong. Now noticed that what childNodes.length gives is the number of attributes I have in total, so in my XML, each node has 2 attributes, childNodes.length is number_of_nodes*2 (number_of_nodes*attributes_in_each_node) Anyway, tested it in my code, and works fine. Thanks!!

hugomg Over a year ago

@Ishmar: The reason that the childNodes.length might be off is because it also counts the subobject nodes and because, in some browsers, it also counts the whitespace nodes between the attribute elements.

J. Rambo · Accepted Answer · 2013-03-11 01:40:58Z

1

The problem you are running into is that technically "attributes" of subobject are also children of object. Remember that any element is a Node object, and on that Node you can get all childNodes. You can do that and process each "Element" node and determine if it is an "attribute" Node.

See http://www.w3schools.com/jsref/dom_obj_node.asp for more information on this.

answered Mar 11, 2013 at 1:40

J. Rambo

1251 gold badge2 silver badges8 bronze badges

Collectives™ on Stack Overflow

reading XML attributes in javascript

2 Answers 2

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related