Reviewing element history and inspecting changes

Every element in the model, including diagrams, has its own history, and you can review it in any open project.

A new version of the element is created once you modify element properties, for example, update the documentation, change the multiplicity or type of the element, create a new attribute or operation. A new version of the diagram is correspondingly created after you modify its properties, for example, rearrange the diagram layout.

To display the history of the element, do one of the following

• Right-click the element or its symbol and from the shortcut menu select History.
  
• Select the element or its symbol and press Ctrl + H.
• Open the Specification window of the element and click the History button .
• If it's a diagram, right-click an empty space on the diagram pane and from the shortcut menu select History.

As a result, the History panel of that element opens at the bottom of the client application (for example, MagicDraw or a Cameo Suite product, such as Cameo Systems Modeler) window. The highlighted row indicates current changes that are not yet committed. If you want to refresh the list of versions, perform the same actions as for opening the panel.

A list of project versions in the History panel.

You can compare any two versions of the element to see the differences between them.

To compare element versions

1. While holding down Ctrl, select the versions you want to compare.

   Only two versions can be compared. Hence, if you select three or more items, be aware, only two of them, that is, the latest and the earliest version, are taken for comparison.

   If you want to compare subsequent versions, it is enough to select the later one.

2. Right-click the selection and choose:
   
   
   • Quick Diff – to inspect the changes of element property values (such as documentation, type, or multiplicity) in a compact form. 
   • Full Diff – to inspect the changes of diagrams or element property values in a detailed form as well as check out the properties of new relationships and directly related elements (such as new or modified attributes and operations).

   

    You can also choose the same commands from the toolbar of the History panel.

After you select the Quick Diff command, the dialog opens showing changes in element property values (see the following figure). Different colors help you to identify new, modified, and deleted values. Exact changes in textual value of the selected property can be analyzed in the Text Diff box. If you want to see the original texts of both versions, click the Compare property values button  on the toolbar of the dialog to open the Compare property dialog and then click Original Texts.

An example of the Quick Diff dialog of an element (class).

After you select the Full Diff command for an element, the Difference Viewer dialog opens showing changes in element property values as well as detailed information of directly related elements and new relationships (see the following figure). For more information about using this dialog, see Analyzing comparison results.

An example of the Difference Viewer dialog of an element.

After you select the Full Diff command for a diagram, the Difference Viewer dialog opens showing all changes in the diagram (see the following figure). For more information about using this dialog, see Viewing and analyzing differences of modified diagrams.

An example of the Difference Viewer dialog of a diagram. 

Be aware that neither Quick Diff, nor Full Diff considers diagram layout changes. Hence, to see these changes you must initiate the comparison of entire project versions. For this, select a couple of project versions in the History panel and on the shortcut menu click Compare Projects. For more information, see Analyzing comparison results.