The Changes & Versions Tool can be opened from the main MetaEdit+ launcher with Repository | Changes & Versions, or with the similar toolbar button. It shows you what changes you have made to models, helping you document the version history of your models. If your MetaEdit+ license has the API features, it also offers integration with an external Version Control System (see Section 3.5).

The history is shown as a tree with Versions at the top level, containing Transactions, containing Graphs or Objects that changed in that transaction. In Figure 3–50 we can see that the current transaction has changed two graphs, Stopwatch and WatchModels. Stopwatch has had two new objects and three relationships added. WatchModels is shown in gray, as there were no changes on the graph level, only a property change to an individual object in the graph. With his memory suitably refreshed by this information, the user has entered a comment describing the changes in this transaction.

The information in the tree is built when the window is opened, when a transaction is committed or abandoned, or when the Refresh button is pressed. By default the tree shows only the current Working Version of the current user is shown, but the Show all versions checkbox can broaden this to previous versions and all users. The changes for an element in the tree can be inspected with pop-up menu actions Open (Section 3.4.1) and Compare (Section 3.4.2). The Graphs and Objects radio buttons choose whether to show graphs with the objects that have changed in them, as in the figure, or objects that have changed and the graphs that contain them. The default is Graphs, but in cases where only a few objects have changed, but each is used in many graphs (possibly deep within them), Objects may be clearer. You can choose to Ignore representations when calculating what has changed, so simple graphical rearrangements of diagram elements do not clutter the display. Show by project inserts an extra level in the tree below transactions, grouping the changes by project.

The comment text box allows you to write a description of the changes in the selected element — a Version, Transaction or Graph. All comments within the current Working Version are editable; previous versions’ comments are read-only. You can Commit or Abandon the current transaction (as in the Launcher). Save Version will commit the current state as a version: see Section 3.4.3; with Save as Release checked, it will ensure all changes are versioned and commented: see Section 3.5.5.

Color and symbols are used to highlight specific type of change: