How to send BPMN diagram to server?

Hi,

I’m trying to build first test process. Simple one. Few tasks - approval process.
So I build diagram. In flows (transition) from exclusive gateway I set expressions:

#{something==xyz'}

Expressions should look like that? But this generates error when I send it to server from menu “Start process instance…”:

Missing attribute 'scriptFormat' for 'script' element | resource akceptacja-faktur.bpmn | line 52 | column 29 [ deploy-error ]
    
  Cannot instantiate process definition approval-process:1:177f05f0-8a96-11eb-9797-049226bdb658: Unknown property used in expression: #{something==xyz'}. Cause: Cannot resolve identifier 'something' [ start-instance-error ]

? Flows must have some rules - ABC of BPMN. This is probably something with variables but we have here vicious circle - no way to define variables in modeler so how to send process without variables when they are needed? Send from Modeler not with ‘scripts’.

Other questions:
Tasks need some info about person who completed them, date and so on. So I can send anything I want with REST at any moment this information? I do not have to define them earlier?

How can I create service task that saves to database some information when it is completed? For instance who made it, when… I know you are script lovers and there’s no menu for that. Do you have some ready to use script that works with MySQL with info how to use it? I could write it in JS, Python, PHP whatever but I hate Java …

Thanks for help

expression should be #{something==xyz'}, missing surrounding quote ' the around the value xyz.

Can you upload your bpmn file to check this? Maybe asyncBefore=true need to be set in the activity.

Thanks. Not that problem. I have correct syntax #{something=='xyz'} - just typo in the post.

@mkelton Does your process is executed synchronously?

What does it mean? I clearly wrote that I created BPMN diagram in modeler and I try to publish it (send to the server). Process is not running synchronously, asynchronously or whatever because menu “Start process instance…” is simply not working.