SOA Magazine IV 01.2015

processes. So, as we implement more and more processes, the number of new types for each new
process rapidly decreases allowing us to reduce implementation complexity and times.
Then on the BpmLib we created our own java class representing a payload item, containing the name of
the item (a key to a resource file), its value, type, if it is editable or read only, and if it is visible. Lastly we
expose two methods:
getTaskPayload: for a given tasknumber returns a list of payload items;
updateTaskPayload: for a tasknumber and a Map updates the task
payload of the task.
GetTaskPayload Method
The getTaskPayload method starts by calling the following code:
ITaskMetadataService.getTaskDefinition(context,task).getWorkflowConfiguration().getPayload().getMessageAttribute();
It returns a list of MessageAttributeType. Each MessageAttributeType represents one entry of the task
payload that we see on the .task file. While this gives us some information (name, type, and if it is
updatable) it is not enough, so we need to also get the actual schema of the payload. This schema is
available on the MDS, and there are several ways to access it. We chose to use the URL
http://[host]:[port]/soa-infra/services/[partition]/[composite]/[path_to_file]/[name_of_task]Payload.xsd
We can feed this url to the XSDBuilder like
XMLSchema schema = new XSDBuilder().build(url);
and get an object representing the payload. From here is just a matter of iterating
MessageAttributeType list and for each item get the corresponding XMLElement of the payload and
build our own PayloadItem object to return.
UpdateTaskPayload
The updateTaskPayload method receives the values to update in a Map where the String
(key) is the name of the payload item, and the Object (value) is its value. The actual class of the Object is
dependent on the type of the payload item. For simple types it's the closest equivalent in java to the
type, for example a String, an Integer, or a Date. For complex types it's a String with the XML value that
needs to be stored. It starts by calling the Task.getPayloadAsElement() method to get an XMLElement
with the current payload. Then it also gets the XMLSchema in the same way as the getTaskPayload. This
is needed to know the type of each payload item. It then updates the XMLElement with the values
passed in the parameter and calls the ITaskService().updateTask(context, task) method to save the
changes.
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