portfolio/pages: Add info about timeline

New feature in Mahara 18.10: You can view old versions
of your portfolio in a timeline view (Bug #1742347).

manual-build @ 0cb0b339

-Subproject commit 0e381cd16d7bd9a728cbfd9512d9288f22458fc2
+Subproject commit 0cb0b339d2a0d1e5b3b543f8b5304eec5dc1d55c

source/portfolio/pages.rst

@@ -522,15 +522,16 @@ You can view a page to check what it looks like when somebody else sees it. Go t
 
       * Click the *Print* link |print icon| to open the print dialogue. Using this print functionality, your portfolio pages are printed in the current layout, with collapsed blocks or artefacts uncollapsed so you can see their content easily. Note: Links are not yet active and linked files or embedded media are not accessible.
       * Click the *Delete* link |delete icon| to delete your page.
+      * |new in Mahara 18.10| Click the *Timeline* link |timeline icon| to view previous versions of your portfolio. This icon is only visible when you saved your page to your timeline.
+      * |new in Mahara 18.10| Click the *Save to timeline* link |save to timeline icon| when you want to save a particular state of your page to your timeline so you can go back to it later and compare it to your current state. The comparison would be manual.
 
       As someone viewing another person's portfolio, you can:
 
       |three dots expanded|
 
-      * Add or remove a page from your watchlist: Click the *Add page to watchlist* link if you want to be informed when changes are made to the page. When you make changes to the page or a block on the page, a notification is triggered and sent to anyone who is watching the page. :index:`This <single: Trigger watchlist notification when journal entry is added to a journal in a page>` is also the case when you add a new journal entry to a journal that is displayed on your page even when you do not add the entry via the page. If you no longer wish to receive these notifications, remove the page from your watchlist by clicking the link *Remove page from watchlist*.
-      * Report objectionable content for this page: If a page contains offensive artefacts, you can report them to the administrator and provide an explanation why you think the content is offensive.
-
-      These functionalities are only available on other people's pages as they are not needed on your own.
+      * Add or remove a page from your watchlist: Click the *Add page to watchlist* link if you want to be informed when changes are made to the page. When you make changes to the page or a block on the page, a notification is triggered and sent to anyone who is watching the page. This is also the case when you add a new journal entry to a journal that is displayed on your page even when you do not add the entry via the page. If you no longer wish to receive these notifications, remove the page from your watchlist by clicking the link *Remove page from watchlist*.
+      * Report objectionable content for this page: If a page contains offensive artefacts, you can report them to the administrator and provide an explanation why you think the content is offensive. Once you have reported the material, you see *Objectionable material reported* instead of *Report objectionable material*.
+      * |new in Mahara 18.10| Click the *Timeline* link |timeline icon| if you want to view an older version of the page.
 
 #. The artefacts that you placed in the page.
 #. Click the *Add a comment* link |add a comment| to be taken to the *Details* page for this artefact to leave a comment.
@@ -611,3 +612,41 @@ When you attempt to delete a page or collection, you get the chance to :ref:`exp
       We recommend you export your portfolio in both HTML and Leap2A formats so that you can view them without the need of Mahara (HTML) or can import them back into the same or another Mahara instance or another portfolio software that supports the Leap2A format.
 
 #.  Click the *Yes* button if you want to continue with the portfolio deletion or the *No* button if you want to keep it.
+
+.. index::
+   single: Portfolio; Timeline
+   single: New in Mahara 18.10; View old versions of a portfolio page
+
+.. _timeline:
+
+|new in Mahara 18.10| Timeline of a page's development
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. warning::
+   This feature is experimental.
+
+Portfolios often show progress over time. However, what did a particular portfolio page look like at the start of the development process, a month ago or two days ago? The timeline makes those changes over time visible and allows the viewer to go back in time and look at an old version of the portfolio page.
+
+.. note::
+   As portfolio author, you need to save a state of a page to the timeline manually.
+
+.. figure:: /images/timeline.*
+   :alt: Jump between old versions of a portfolio
+
+   Jump between old versions of a portfolio
+
+#. After you clicked the *Timeline* link |timeline icon| on a page that has a timeline, you can see the page title.
+#. The word "Timeline" indicates that you are in the timeline view of the page.
+#. You can always return to the live view of the page by clicking the *Display page* link.
+#. **From**: Choose a starting date for the first version that you want to see.
+#. **To**: Choose an end date. The default date is the one is tomorrow's date so that any version saved to the timeline today are still displayed.
+#. If there is no previous version, the *Previous version* button is greyed out |timeline previous inactive|.
+#. The dates for which timeline versions are available.
+#. The date of the active version that you are viewing is highlighted.
+#. Click the *Next version* button |timeline next active| to scroll to later versions of the page.
+#. The page title is shown.
+#. The date and time when the version was saved is displayed.
+#. The version number is shown.
+#. Click the *Go to the previous version* button |timeline previous active| to go to the previous version of the portfolio.
+#. Click the *Go to the next version* button |timeline next active| to advance to the next version.
+#. The content of the page is displayed as it appeared in that version.

source/shortcuts.rstext

@@ -122,6 +122,16 @@
 
 .. |delete icon| replace:: :fonticon:`fa fa-trash fa-fw fa-1x text-danger`
 
+.. |timeline icon| replace:: :fonticon:`fa fa-code-fork fa-fw fa-1x`
+
+.. |save to timeline icon| replace:: :fonticon:`fa fa-floppy-o fa-fw fa-1x`
+
+.. |timeline next active| replace:: :fonticon:`fa fa-chevron-circle-right fa-fw fa-2x timeline_icon_active`
+
+.. |timeline previous active| replace:: :fonticon:`fa fa-chevron-circle-left fa-fw fa-2x timeline_icon_active`
+
+.. |timeline previous inactive| replace:: :fonticon:`fa fa-chevron-circle-left fa-fw fa-2x timeline_icon_inactive`
+
 .. |details| raw:: html
 
    <a class="link-blocktype">