Do I need to run the Nested Pages Migrator?

Starting with XWiki 7.2, XWiki supports the concept of Nested Pages.

There's an extension available called the Nested Pages Migrator to help you convert Terminal pages (i.e. pages that cannot have children) into Nested Pages.

You should check the Nested Pages migration guide to know more.

You don't need to migrate individual wiki pages; you can continue to access and edit them as before. The Nested Pages Migrator Application is useful if you want to migrate from the old Parent-Child hierarchy to the new Nested-Pages hierarchy. Otherwise, if you just want to add child pages to an existing page that is not a space home page (in the old terminology) then you can simply rename that page in order to make it "non-terminal".

For example, here's what would happen to the breadcrumbs after you upgrade:

If you had this before the upgrade:

• URL: /xwiki/bin/view/A/B
• Breadcrumb: Home/X/Y/B

Then after the upgrade (without any migration) you'll have:

• URL: /xwiki/bin/view/A/B
• Breadcrumb: Home/A/B

So you "lose" the parent-child hierarchy. The information is not lost, but the relationship is no longer used by the breadcrumb. By default, the new breadcrumb uses the page location (what you have in the URL).

So you have 3 options:

1. You don't care about the old parent-child hierarchy. In this case you
   don't need to do anything.
2. You want to keep using the parent-child hierarchy. In this case you'll want to read about hierarchyMode configuration in the Nested Pages migration guide.
3. You want to convert/migrate the Parent-Child hierarchy to the
   Nested-Pages hierarchy. In this case you'll either use the Nested Pages
   Migrator, which automates this for you, or you'll need do it manually by moving
   pages around (e.g. in the example above you would move page B from A to X/Y so that its location becomes X/Y/B).