Simplify an XMLObject limited to XMLElements with a specific tag

Questions
1

Hello,

I would like to simplify an XMLObject by only retrieving the XMLElements with a specific tag.

I would like a code based with the use of XMLElements as function.

I try this code :

XMLtest3 =  Cases[XMLtest, _XMLElement, Infinity] //. XMLElement[tag : "YO", attributes_, data_] :>  XMLElement[tag , attributes, data]

Definition of the XMLObject:

XMLtest = 
  XMLObject[
    XMLElement["YO", {}, 
      {XMLElement["YO", {}, 2], 
         XMLElement["BA", {}, 
           {XMLElement["YO", {}, 
             {XMLElement["BA", {}, 2]}], XMLElement["BA", {}, 2]}]}]]

TestSimplificationXMLObject_exemple1.gif
TestSimplificationXMLObject_exemple1.gif360×342 5.92 KB

I would like to keep only the XMLElements with the tag “YO” and to preserve a tree structure for the XMLObject.

May you help me to correct the code given?

Thank you for your help

2

Since you want to preserve the tree structure, does this suit your needs?

Cases[XMLtest, XMLElement["YO", {}, _], Infinity]
3

Thank you for your answer.
But, the Cases function permit to select all the XMLElements with the desired tag but the hierarchical structure (or tree) of the XMLElements is lost.

4

How about:

DeleteCases[XMLtest, XMLElement[tag_, attributes_, data_] /; tag != "YO", Infinity]