[[bookmarked-pages]]
= Bookmarked pages

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The Wicket viewer supports the automatic bookmarking of domain objects, as per xref:refguide:applib:index/annotation/DomainObjectLayout.adoc#bookmarking[@DomainObjectLayout#bookmarking()].
However, it does _not_ support bookmarking of action prompts (xref:refguide:applib:index/annotation/ActionLayout.adoc#bookmarking[@ActionLayout#bookmarking()]).

Whenever a bookmarkable object/action is visited, then a bookmark is created.
To avoid the number of bookmarks from indefinitely growing, bookmarks that have not been followed after a while are automatically removed (an MRU/LRU algorithm).
The number of bookmarks to preserve can be configured.


== Screenshots

The following screenshot shows how bookmarks are rendered in the Wicket viewer:

image::bookmarked-pages/panel-estatio.png[width="800px"]

This screenshot demonstrates that bookmarks can be nested.
Some - like `Property` and `Lease` - are root nodes.
However, `Unit` is bookmarkable as a child of `Property`.
This parent/child relationship is reflected in the layout.

== Domain Code

To indicate a class is bookmarkable, use the xref:refguide:applib:index/annotation/DomainObjectLayout.adoc[@DomainObjectLayout] annotation:

[source,java]
----
@DomainObjectLayout(
    bookmarking=BookmarkPolicy.AS_ROOT
)
public class Lease { /* ... */ }
----

To indicate a class is bookmarkable but only as a child of some parent bookmark, specify the bookmark policy:

[source,java]
----
@DomainObjectLayout(
    bookmarking=BookmarkPolicy.AS_CHILD
)
public class LeaseItem { /* ... */ }
----


== User Experience

The sliding panel appears whenever the mouse pointer hovers over the thin blue tab (to the left of the top header region).

Alternatively, `alt+[` will toggle open/close the panel; it can also be closed using `Esc` key.


== Configuration

The maximum number of bookmarks that are shown can be overridden using the  xref:refguide:config:sections/isis.viewer.wicket.adoc#isis.viewer.wicket.bookmarked-pages.max-size[isis.viewer.wicket.bookmarked-pages.max-size] configuration property.

