Where declared, the common component arguments are Argument_EventName, Argument_SenderName and Argument_SenderID.
OnBeforeChange runs after the new Edit value has been written to EntryData and the component has been marked as changed, but before recalculation and OnChange. Its Result is ignored.
The default Edit OnChange formula runs after the first recalculation. Its Result does not control the value change. When the formula completes successfully, a second recalculation runs; when it fails, this second recalculation does not run. Both desktop and web use this update sequence.
The default Label OnGetLabel formula returns the displayed caption. A formula error produces an empty caption; the component does not fall back to the entry value or its default caption. The same caption path is used on desktop and web.
OnChange runs after a Memo value change. Its Result is ignored. Recalculation runs before the formula and, when the formula is valid, after it. In the web wizard route the value can be written before the normal update check, so this event can be skipped when no change is detected.
The default OnTimer formula runs periodically according to the component's Interval setting. Its Result is ignored and it has no declared arguments. The timer runs in Edit and Print modes, and is stopped when the component is disabled or read-only. Desktop and web use the same interval setting.
OnGetCaption returns the caption of each tree node. Argument_DataID, Argument_NodeID and Argument_ParentNodeID identify that node. Variables named Argument_<EntryName> are declared for global entries, but at runtime only the values belonging to the current tree object are populated. The same data-loading path is used on desktop and web.