Assist when writing (FEEL) expressions

[saig0]

Is your feature request related to a problem? Please describe.

Zeebe supports (FEEL) expressions for different attributes. In some cases, an attribute is always an expression. In other cases, an attribute can be a static value or an expression. If the attribute value is an expression then it starts with "=" (an equal sign).

For me, it is annoying that I need to write always "=" before my expression, even if the attribute is always an expression.

Some users may also not be aware that they need to write an expression for an attribute and try to write a static value.

From the Zeebe documentation: https://docs.zeebe.io/reference/expressions.html

The following attributes of BPMN elements require an expression:

• Sequence Flow on an Exclusive Gateway: condition
• Message Catch Event / Receive Task: correlation key
• Multi-Instance Activity: input collection, output element
• Input/Output Variable Mappings: source

Additionally, the following attributes of BPMN elements can define an expression optionally instead of a static value:

• Timer Catch Event: timer definition
• Message Catch Event / Receive Task: message name
• Service Task: job type, job retries
• Call Activity: process id

Describe the solution you'd like

If the attribute value is always an expression then I don't need to write "=" before the expression. For example, by adding a fixed field with "=" in front of the text field.

If the attribute value can be an expression or a static value then I can toggle a field that decides if it is the expression or not.

Additionally, it may help new users if the modeler explains the meaning of "=". For example, by having a short description under the field or as a hover text (e.g. "an expression starts with =").

Describe alternatives you've considered

No.

Additional context

An idea for the UI:

[pinussilvestrus]

Nice idea, thanks for opening 👍 . We plan some investigations on how to support creating JUEL expressions in the Camunda Modeler Properties Panel, which tackles a similar problem. Maybe we can combine both problems in the future.

[ChrisKujawa]

Some users may also not be aware that they need to write an expression for an attribute and try to write a static value.

I run into this today as well. Please implement this.

[vtexier]

Another enhancement proposal is that input field accepting/requiring an expression should be multi-line. ;)