Snapshots & Comparison

Every time a diagram or a form is saved, the modeler records a snapshot of its state. Snapshots let you review how it evolved, restore an earlier state, and compare two saved states. Forms are kept this way from 2.3.0; before that, only diagrams were.

Browsing Snapshots

Open a diagram or a form and use the snapshot (history) button in the modeler toolbar. A selector lists the saved snapshots of what is open, newest first, including who saved them and when. Use the search field to narrow the list.

The list holds the saves that changed the content itself. Saving only a rename or a new description is recorded as well, but is not offered as a state to go back to, since going back to it would change nothing. The number of entries the list shows is capped by cibseven.webclient.modeler.history.maxResults (default 30, available from 2.3.0).

Restoring a Snapshot

Selecting a snapshot loads that saved state into the editor. The restored content becomes the working state — save it to make it the newest snapshot. Restoring is not a save in itself: saving stays disabled until you edit something. Nothing is deleted by restoring: the snapshots it was restored from remain in the history.

Comparing Snapshots

The compare button appears as soon as there is a second snapshot to compare with, and opens the comparison view:

1. Select two snapshots to compare (typically an older and a newer state).
2. Press Compare. The headings above the comparison name the two versions being shown, so changing a selection afterwards does not change what is on screen until you compare again.

BPMN

A BPMN comparison is a structural diff (powered by bpmn-js-differ), so renamed properties, changed task types and added or removed flows are found even when the visual layout barely changes. It opens on the Visual diff tab, which marks the changes on the diagram itself and lists them beside it, layout-only movements apart from semantic changes. The Code diff tab shows the same two versions as XML.

DMN and forms

There is no structural differ for decision tables or for forms, so their comparison is the Code diff: the two versions side by side, with additions and removals highlighted, DMN as XML and a form as its JSON schema. A form schema is indented before it is compared, so the way one save happened to be formatted is not reported as a change.

Reading a form comparison, keep in mind that it compares the text: a field dragged to another position appears as removed where it was and added where it now is, rather than as a move.

Retention

A scheduled job keeps the newest cibseven.webclient.modeler.history.versionLimit versions of every diagram and every form (default 50) and deletes the snapshots below them, so the history of something edited for years does not grow without end. cibseven.webclient.modeler.history.cron controls when it runs (default: midnight daily). Snapshots belong to one diagram or form: cleaning one never touches another.

The properties are listed in the Configuration Reference, and the snapshots live in mod_processes_diagrams_aud and mod_forms_aud — see Database Schema.