Understanding the Snapshots feature within DRM

A snapshot is an object that captures a map at a particular point in time. You can use this snapshot to rebuild the map and the objects that it contains—container, container parts, topics, images, referable content, sub-maps, and so on—exactly as they were when the snapshot was created.

When you create a snapshot for a map, the system creates an .xml file that contains the list of all the objects in the map (and sub-maps, if any) along with their current version numbers.

For example, consider the following map, which contains a topic and a sub-map: 
<!DOCTYPE bookmap PUBLIC "-//IXIA//DTD DITA Map for Release Management//EN" "IxiaMap-releasemanagement.dtd">
<bookmap id="ddp1441205293768" xml:lang="en-us">
	<title>Sample map</title>
	<containerref href="kiy1441205259960.ditamap"/>
	<chapter keyref="bhi1441205335829"/>
	<chapter format="ditamap" keyref="dsi1441206564020"/>
</bookmap>

The following code shows the contents of the snapshot file for this map. The snapshot includes the objects referenced in the topic (in this case, an image and referable content) as well as the objects in the sub-map (in this case, a task that also includes an image).

For each object in the map—that is, the map itself as well as all the objects that it contains: container, container parts, topics, images, referable content, sub-maps (and their contents), etc.—the following information is kept:
  • Status of the object
  • Link to the object in the IXIASOFT CCMS
  • Navtitle
  • Revision number
  • Object type

This information allows the CCMS to recreate the map exactly as it was when the snapshot was created. As with any object, you can search for a snapshot in the Content Store. You can also output a snapshot.

Important note

To create the snapshot, the system uses the latest released revisions of the objects in the map. Therefore, if you have locked documents in your map, the snapshot will not include these locked revisions but rather the latest released revisions of these objects.

Why use snapshots?

Creating a snapshot does not create copies of the map and its objects. It's simply a text file that lists the map's contents at a specific point in time, so creating a snapshot has virtually no impact on the Content Store. Another advantage of snapshots is that you can create a snapshot from a map that is in any state, as long as the map is not locked.

When using snapshots, you can:
  • Generate the output of a snapshot: At any time you can see the content of a snapshot by generating its output. When you generate the output of a snapshot, the Output Generator retrieves from the Content Store the versions of the map and its objects as specified by the snapshot. New files are not created.
  • Keep a historical record of all your documentation releases: Every time that you release your documentation or at important milestones, you can make a snapshot of your map. This ensures that you can see the content of a specific release at any time by generating its output.