XML help, please

Targets macOS
1

I have an XML file containing elements named “asset” that each represent a file like the one listed below.

<asset id="r2" name="00018M" uid="DF36C3050CEDE81F705DC99FCF0E1487"> <media-rep kind="original-media" sig="DF36C3050CEDE81F705DC99FCF0E1487" src="file:///Volumes/Storage2/00018M.MXF"> </media-rep> <metadata> <md key="com.apple.rawToLogConversion" value="0"/> <md key="com.apple.kMDItemProfileName" value="SD (6-1-6)"/> </metadata> </asset>

I can get the file’s attributes such as “name” and “uid” from the “assets” element easily. But I can’t figure out how to get the corresponding “src” attribute from the “media-rep” element.
Any help appreciated.

2

media-rep is a Child of asset
For constant kXML

<?xml version="1.0" encoding="UTF-8"?> <catalog> <asset id="r2" name="00018M" uid="DF36C3050CEDE81F705DC99FCF0E1487"> <media-rep kind="original-media" sig="DF36C3050CEDE81F705DC99FCF0E1487" src="file:///Volumes/Storage2/00018M.MXF"> </media-rep> <metadata> <md key="com.apple.rawToLogConversion" value="0"/> <md key="com.apple.kMDItemProfileName" value="SD (6-1-6)"/> </metadata> </asset> </catalog>
get “src”

[code]Sub Action()
Var xml As New XmlDocument(kXML)
Var root As XmlNode
root = xml.DocumentElement

Var asset As XmlNode
Var media As XmlNode

asset = root.FirstChild
For idx As Integer = 0 To asset.ChildCount - 1

media = asset.Child(idx)
Var src As String = media.GetAttribute("src")
Break

Next

End Sub[/code]

3

XML + XQL is probably much simpler

// find all media-reps that are contained by an asset
// and get their src attribute

// // is the descendent operator
// see http://www.ibiblio.org/xql/xql-proposal.html

Dim srcs As XmlNodeList = docNode.XQL("//asset/media-rep/@src")

For i As Integer = 0 To srcs.Length - 1
  
  Dim currentSrc As XmlNode = srcs.Item(i)
  
  System.debuglog currentSrc.Value
  
Next
4

Thank you, Oliver and Norman for your solutions. Both work fine for me and I am happy to have learned two ways of doing this.
Many thanks.

5

@Norman Palardy
Can you take the XML +XQL method one step further and find just the “src” item that has the value of “x”? Or is it necessary to iterate the srcs list?

6

with XQL you can find node with a bunch of criteria
https://www.w3schools.com/xml/xpath_intro.asp

Start a new project
In Windows1 add this String constant to the window

Private Const kXML as String = <asset id="r2" name="00018M" uid="DF36C3050CEDE81F705DC99FCF0E1487">
     <media-rep kind="original-media" sig="DF36C3050CEDE81F705DC99FCF0E1487" src="file:///Volumes/Storage2/00018M.MXF">
     </media-rep>
     <metadata>
          <md key="com.apple.rawToLogConversion" value="0"/>
          <md key="com.apple.kMDItemProfileName" value="SD (6-1-6)"/>
     </metadata>

     <media-rep kind="original-media" sig="DF36C3050CEDE81F705DC99FCF0E1487" src="00118M.MXF">
     </media-rep>
     <media-rep kind="original-media" sig="DF36C3050CEDE81F705DC99FCF0E1487" src="file:///Volumes/Storage2/20018M.MXF">
     </media-rep>
     <media-rep kind="original-media" sig="DF36C3050CEDE81F705DC99FCF0E1487" src="file:///Volumes/Storage2/03018M.MXF">
     </media-rep>
     <media-rep kind="original-media" sig="DF36C3050CEDE81F705DC99FCF0E1487" src="file:///Volumes/Storage2/00418M.MXF">
     </media-rep>

</asset>

this code in the open event finds a specific src value

Sub Open() Handles Open
  // find all media-reps that are contained by an asset
  // and get their src attribute
  
  // // is the descendent operator
  // see http://www.ibiblio.org/xql/xql-proposal.html
  Dim xmlDoc As New XmlDocument(kXML)
  Dim docNode As XmlNode = xmlDoc.DocumentElement
  
  Dim srcValueToFind As String  = "file:///Volumes/Storage2/20018M.MXF"
  
  Dim srcs As XmlNodeList = docNode.XQL("//media-rep[@src='" + srcValueToFind + "']")
  
  For i As Integer = 0 To srcs.Length - 1
    
    Dim currentSrc As XmlNode = srcs.Item(i)
    
    System.debuglog currentSrc.ToString
  Next
End Sub
7

Thank you, Norm, for the example and link. I’m beginning to get it!