In some cases it is useful to create a BizTalk message without mapping it from another message.
If you have a Message Assign shape and you access a distinguished field on the message like
msgSample.ErrorCode = “4711”;
without a Transform shape in advance you get the following error during compiling
Message part has not been initialized in construct statement
This is because the xml message has not been initialized. For some reason it is necessary that the “empty” message needs to already contain a tag for the field ErrorCode.
To avoid this issue, you would add a Transform shape with a map, where the root node of the source schema is linked with the field ErrorCode on the target schema. Without mapping you need to construct this manually. For me, the following worked well:
I added a variable with name tempXml of type System.Xml.XmlDocument to the orchestration. In an expression shape I loaded an XML template and constructed the message.
tempXml = new System.Xml.XmlDocument();
tempXml.LoadXml(“…”);
construct msgSample
{
msgSample = tempXml;
msgSample.ErrorCode = “4711”;
}
The XML template for LoadXml can be generated on the schema file in Solution Explorer.
Another way could be to call custom code like
construct msgSample
{
msgSample = CustomClass.CustomMethod(...);
msgSample.ErrorCode = “4711”;
}
The method should be declared in a separate c# project as follows
public class CustomClass
{
public static XmlDocument CustomMethod(...)
{
...
}
}
