Add Photoshop Property to XMP Embedded in JPG and Save

Load JPG, access XMP metadata, and adds an additional Photoshop property. The JPG in this example already contains a number of Photoshop properties. This example adds one more: the photoshop:Instructions property.

    ' Visual Basic Example to load a JPG and add a new Photoshop schema property.
    ' In this example, a number of Photoshop schema properties already exist.
    ' This new property is added by calling
    ' xmp.AddSimpleStr xml, "photoshop:Instructions", "These are special instructions..."
    ' The AddSimpleStr method locates the correct rdf:Descripton node
    ' and inserts a new XML node.
    
    ' Add references to these ActiveX components in your VB6 project:
    ' Chilkat XML
    ' Chilkat XMP
    ' The AgencyPhotographer-Example.jpg test JPG can be downloaded from
    ' http://www.chilkatsoft.com/testData/AgencyPhotographer-Example.jpg

    ' Create an instance of the XMP ActiveX and unlock it.
    Dim xmp As New ChilkatXmp
    success = xmp.UnlockComponent("anything for 30 day trial")
    If (success = 0) Then
        MsgBox "Failed to unlock"
        Exit Sub
    End If
    
    ' Load a JPG file.
    success = xmp.LoadAppFile("AgencyPhotographer-Example.jpg")
     If (success = 0) Then
        MsgBox xmp.LastErrorText
        Exit Sub
    End If
   
   ' Get the 1st (and only) XMP in this JPG.
    Dim xml As ChilkatXml
    Set xml = xmp.GetEmbedded(0)
    If (xml Is Nothing) Then
        MsgBox xmp.LastErrorText
        Exit Sub
    End If
        
    ' Add a new Photoshop property.
    xmp.AddSimpleStr xml, "photoshop:Instructions", "These are special instructions..."
    
    ' Save the JPG with the update.
    xmp.SaveAppFile "out.jpg"
    
    ' IMPORTANT: After saving the JPG, the XML object should be discarded.  If you
    ' wish to continue editing the embedded JPG, you must re-fetch the XML object:
    Set xml = xmp.GetEmbedded(0)