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xmlhaskellhxt

How do i replace Nodes in HXT?


Given a sample xml file:

<root>
  <tag attr="value">Content</tag>
  <tag attr="value2">Content</tag>
</root>

how do i replace every tag with a different tag so i get a different file:

<root>
  <tag2 attr2="value"/>
  <tag2 attr2="value2"/>
</root>

The documentation [1] seems to use Filters, is there a way to accomplish this with arrows alone?


Update

i am now at the point where i can replace a node like this:

runX $ readDocument [] "in.xml" 
       >>> processTopDown( 
               (eelem "tag2" += sattr "attr2" "XXX" ) 
               `when` (isElem >>> hasName "tag") ) 
       >>> writeDocument [] "test.xml"

but i have no idea on how to get the attribute right.


[1] http://www.haskell.org/haskellwiki/HXT#Transform_external_references_into_absolute_reference


Solution

  • Try setElemName, processAttrl, and changeAttrName from Text.XML.HXT.XmlArrow:

    runX $ readDocument [] "in.xml" >>> transform >>> writeDocument [] "test.xml"
      where
        transform = processTopDown $
          ( setElemName (mkName "tag2") >>>
            processAttrl (changeAttrName $ mkName . attrMap . localPart)
          ) `when` (isElem >>> hasName "tag")
        attrMap "attr" = "attr2"
        attrMap a = a
    

    This works for me with your sample document.