<createSnapshot> Step

This step creates a snapshot of the current installed state of the component being installed. You can specify any number of <createSnapshot> steps within an install block.

The named snapshot block cannot declare any required parameters because the <createSnapshot> step does not support argument passing. Argument passing is not supported because it would also require support for argument collection and passing during a later comparison on the resulting snapshot.

A comparison performed on a composite component includes all snapshots that are created directly by that component. The comparison also includes the complete tree of snapshots that are created by the recursive installation of all nested component references. However, snapshots that are associated with top-level component references are not considered. Thus, such snapshots must be explicitly included in the snapshot of the composite component by using the <addSnapshot> capture directive.

In addition, nested components might have some interdependencies that make it necessary to defer snapshot capture until all such components are installed. One example is a nested component that deploys a directory and a nested component that deploys a file into that directory. In such interdependent cases, the containing component should install the nested components by using parameter passing or special install blocks that tell the nested component not to take the snapshot during their install. Then, have the snapshot block of the containing component include appropriate snapshots of the nested components by using the <addSnapshot> directive.

Attributes for the <createSnapshot> Step

The <createSnapshot> step has one required attribute of type entityName, blockName, which is the name of the snapshot block to execute within the component.