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objective-ccocoansxml

Cocoa - Writing NSXMLElement In NSXMLDocument

I am creating an NSXMLDocument, from which I get a file defined in a constant USER_PRINTXML_URL, as follows:

NSXMLDocument *ads_user_printxml = [[NSXMLDocument alloc] initWithContentsOfURL: [NSURL URLWithString:USER_PRINTXML_URL]    options:(NSXMLNodePreserveWhitespace|NSXMLNodePreserveCDATA)                                          error:&ads_err];

Then I use XPath to get to the desired location in the XML file, as follows:

NSArray* ipp_folder = [[ads_user_printxml nodesForXPath:@".//root/printing/IPP"error:&ads_err] objectAtIndex:0];

Now, if I want to add NSXMLElements after the element in the XML file, how do I do it?

I have tried to do the following:

NSXMLElement *s= [ipp_folder objectAtIndex:0];

But this is generating a run time error. I also tried using an NSXMLNode instead of putting the data in an NSArray but again to no avail. I believe the solution is quite simple, but I can't for the life of me find an answer in the docs.

Thanks for any help.

Solution

  • -nodesForXPath:error: returns an NSArray*, but your second code snippet has already applied -objectAtIndex: to that. So, ipp_folder doesn't hold an array, it holds a pointer to an NSXMLNode. Fix its declared type.

    Then, you can identify its parent using the -parent method and its index within the parent's children using the -index method. Then, assuming the parent is an NSXMLElement, you can do:

    [[ipp_folder parent] insertChild:someNewNode atIndex:[ipp_folder index] + 1];