Accessing custom property in parent message (C# step in business process)

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Permalink Reply by Joe Klug on September 5, 2017 at 7:12am

Can you further describe your message flow?  If you want a custom property from one message to be present on another message, you will have to read it from the first one and set it on the second one.

To get the value of a custom property in a C# step:

context.Data.GetProperty("<prefix>", <property_name>", <default_value>");

To set the value of a custom property in a C# step:

string value = context.Data.SetProperty("<prefix>", "<property_name>", <property_value>");

If you need to read the value of a custom property in one C# step, then apply it to a different message in a second C# step, you will need to save that value as a process property.

To set a process property:

context.Properties.Add("<property_name>", "<property_value>");

To get the value of a process property:

string value = context.Properties["<property_name>"];

I hope this helps!

Joe

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Permalink Reply by Per Laustsen on September 5, 2017 at 10:50pm

Hi Joe, thanks for a very swift response.

Message flow is as follows:

1.C# client publish a message to the bus with a custom property.

2.Subsrciber Service endpoint is activated (REST call), and a reply is send back to the bus.

-In the On Publish event (for subscriber), I have a Business Process that saves the result from the REST call to a file. I need to use the custom property from step 1 to name the file.

I have attached a quick drawing of the process, thanks

Attachments:

• Nasdaq Integration Pattern.docx, 28 KB

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Permalink Reply by Joe Klug on September 6, 2017 at 11:09am

Thanks for the details!  This is fairly easy to do, albeit not very obvious.  There is an ESBMessge header property called RequestHeadersToPreserve that is used to tell subscribers to save the value of a custom property on a request message and reapply it to the response message.  You could actually set this in your C# client code.  For example, if you have a property called Task.Filename, then use code similar to this:

myRequestMsg.Header.RequestHeadersToPreserve = "Task.Filename";

Then, in your OnPublish business process you can get the value of that custom property using the GetProperty("Task", "Filename") function on ESBMessage.

Let me know if this works for you,

Joe

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Permalink Reply by Per Laustsen on September 6, 2017 at 11:07pm

This is perfect, thanks.

Very simple and easy to apply!

/Per

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