Update: Tomas Restrepo added a comment to this post in which he explains why this particular ‘feature’ is present – I think its worth repeating here:
…the problem was that the Target Charset property of the assembler actually gets written as two separate elements when serialized to the pipeline XML file, and both must be present for the assembler to actually figure out the encoding to use… So what happens is that the metadata in the actual design time properties for the assembler component only actually represents one of those elements in the serialized format, and this is what the per-instance pipeline configuration dialog uses to ask the user to enter the values. So in essence, the dialog only allows you to edit one of the values and not the other, so you always end up with the component incorrectly configured.
While researching a post about message encoding in BizTalk, I can across this Microsoft Knowledge Base article regarding the TargetCharset property on the XmlAssembler component – it would appear that if the property is set through the Admin Console, it won’t take effect. This is strange, because this bug appears to have been fixed in BizTalk 2004 SP1, but somehow made it back into all versions of BizTalk 2006 & 2006 R2. Furthermore for BizTalk 2006, Microsoft only offer a work-around rather than a Hotfix which is frustrating.
So, what happens when you attempt to set the TargetCharset property? The default encoding when using the XmlTransmit pipeline – without the TargetEncoding property set – is a UTF-8 encoded Xml message (click on the image for a full-size version):
If you change the TargetCharset property on the XmlAssembler component of the default XmlTransmit pipeline in the BizTalk Admin console (as shown below), the change is not picked-up and the same UTF-8 encoded message (as above) is returned; in this case, we’re trying to change it to UTF-16:
To change the encoding, you must create a custom pipeline and use the XmlAssembler with the TargetCharset property set appropriately, as follows:
Using this new custom pipeline with the TargetCharset property correctly configured to output UTF-16 encoded messages, we acheive our desired encoding, as follows (click on the image for a full-size version):
Encoding can also be acheived by setting the XMLNORM.TargetCharset property of the message to be output in an Orchestration Message Assignment shape as follows:
<MessageName>(XMLNORM.TargetCharset) = "UTF-16";
Note, this testing was performed on BizTalk 2006 R2.