How to parse complex XML tree using TouchXml in iPhone.

Question

Hi all, I am trying to build an app which during start-up connects to website and downloads the XML data. Though the data is large(100 KB) and i am using TouchXml for it. The xml is like this.

<?xml version="1.0" encoding="UTF-8"?>
<itemA attA="AAA" attB="BBB" attC="CCC">
      <itemB>
            <itemC1 attD="DDD" attE="EEE" attF="FFF">
                  <itemD>                     
                         <itemE1 attG="GGG">
                                <itemF>ZZZ</itemF>
                                <itemG>
                                      <itemH1 attH="HHH">
                                            <itemG>ZZZ</itemG>
                                            <itemH>YYY</itemH>
                                      </itemH1>
                                      <itemH1 attH="III">
                                      ...                               
                                </itemG>
                          </itemE1>
                          ...
                   </itemD> 
              </itemC1>
              ...
       </itemB>
</itemA>

Here three dots ". . ." presents tens/hundreds of same kind of element. i want to extract each and every attribute and node contents. Initailly i begin with

[CXMLDocument nodesForXPath:@"//itemA" error:nil];

and able to get its attributes and upto first child nodes using -

[CXMLElement childAtIndex:index];

but how i will move further into child nodes and their nodes and get their values. Any help is greatly appreciated.link text

Answer 1

You would probably definitely be better served with using the event-driven parser in this case; NSXMLParser.

Answer 2

You can use XPaths for this:-

  NSArray *nodes = [doc nodesForXPath:@"//itemA/itemB/itemC1" error:nil]; 

This will return all the nodes in the itemC1 element. Note 'doc' is your CXMLDocument object.

Google XPath for the full syntax.