The variable concept describes which data is exchanged between the case file and the workflow, and by what rules this happens.
The most important rule up front: the name of a variable determines where it ends up.
ALL_CAPS_WITH_UNDERSCORES become visible as case placeholders and are available in correspondence.
_- and wf_-prefixed variables stay internal – ideal for intermediate results the user doesn't need to see.
System-reserved prefixes (e.g. FORDERUNG_*) are calculated – don't use them as your own placeholders.
Data flow between case file and workflow
By default, all variables from the case file’s placeholders are loaded into the workflow, and changes are propagated into the workflow during runtime. Conversely, every variable generated within the workflow is saved into the case file’s placeholders immediately after it is created. You’ll find the complete list of loaded variables in the variable reference.
Technical variables (not persisted)
In certain cases, variables should exist exclusively within the workflow and should not end up in the case file’s placeholders. Two conventions apply here:
| Prefix | Meaning |
|---|---|
wf_ / WF_ |
A purely technical workflow variable. Available only within the workflow and its subworkflows, and not saved in the placeholders. |
_ (underscore) |
Any variable starting with an underscore is not persisted. Typically arises as an input in ServiceTask header fields, and as an output value of ServiceTasks and catch events. |
Data type: everything is a string
All variables are stored and used as a string. Calculations or numeric conditions therefore require a conversion, for example via bigDecimal(...).
FORDERUNG_OFFEN = "1.234,50 €" ← string, not a numeric value
bigDecimal(FORDERUNG_OFFEN) > 0 ← convert first, then compare
Locked variables (system-reserved)
The following variables are reserved for system purposes and are not saved in the placeholders:
- all system variables from the variable reference,
- all variables of participants,
- all variables with one of the following prefixes:
| Prefix | Scope |
|---|---|
FORDERUNG_* |
Claim amounts by group and in total |
FORDERUNGSTABELLE* |
Claim tables (HTML/JSON) |
GEBÜHRENTABELLE* |
Fee tables by tier |
ABZINSUNGSTABELLE* |
Discounting tables |
FORDERUNGSSALDO* |
Balances from claims, fees, total |
FORDERUNGSUEBERSICHT* |
Claims overview (HTML) |