The Timeline plugin allows you to add items to a timeline in your Omeka Classic site.

Timeline adds a public page to your navigation, with a textual list of all timelines. This list can be be reordered on the admin-side Timeline page in the left-hand sidebar. Each individual timeline also gets a URL that can be added to your navigation manually, or can be displayed in pages using shortcodes or as part of exhibits using the Exhibit Builder plugin.

Timeline dates and intervals must be in ISO 8601 format (YYYY-MM-DDThh:mm:ss), with a / separator between interval beginnings and ends. If date/interval values are not formatted correctly, the item will be left out of the timeline.

If an item has multiple date values or interval values, the Timeline plugin will accept the first properly formatted value: so, if you have textual dates such as "circa 1850" or "16??" Timeline will ignore these in favor of a numerical value. If an item has both a discrete date value and interval value in the fields mapped by timeline metadata, the interval value will take precedence over the date value. An item with an interval does not need to have a discrete date value.

Admin interface

The Timeline plugin will add a new link to the admin sidebar, "Timeline". Here you will see existing timelines and be able to rearrange them for the public display on the yourinstall/timeline page. This order can be reset with the "Reset Timeline order" button.

You can add a new timeline from this page, or edit either part of existing timelines. You can also delete timelines; you will see a confirmation window.

Creating a timeline

Once you have installed and activated the Timeline plugin, Timeline should appear in the left navigation bar. Clicking on it will take you to the Browse Timelines page.

To create a timeline, click the "Add a Timeline" link.

Link to add timeline

On the Add a Timeline page, enter the following metadata:

  • Title: the name of your timeline, which will be displayed to users (required).
  • Description: an introduction or overview for the timeline.
  • Font: choose from several pre-set combinations of title and description fonts.
  • Item date: a dropdown to select the metadata field to use for item date containing discrete time/date values.
  • Item interval: a dropdown to select the metadata field to use for item date containing time/date span values (the chosen field must use a / separator between two ISO-8601 formatted dates).
  • Item title: a dropdown to select the metadata field to use for item titles.
  • Truncate: if checked, the textual part of each slide will not offer vertical scrolling when needed; instead, the text will fade out at the bottom of the timeline slide.
  • Item description: a dropdown to select the metadata field to use for item descriptions.
  • Status: a dropdown to select whether the timeline is public or not public.
  • Featured: a dropdown to select whether the timeline is featured or not featured.

Once you have entered the metadata, click "Save Changes" to create your timeline. If your timeline was sucessfully saved, you will be taken to the Query page to add items to your timeline.

To edit the timeline's settings later, such as to change the font choice or other display, go back to the Timeline homepage (found at /admin/timeline) and select "Edit Metadata" for the timeline in question. Or, you can click the timeline's title to go to its summary page, and click "Edit Metadata" from there.

Existing timelines listed on browse timeline page

Adding items

Your timeline will appear empty until you populate it. To add items to your timeline, click "Edit Item Query" on the Timeline homepage (found at /admin/timeline) or from the specific timeline's summary page (found at /admin/timeline/show/1 where 1 is the ID number of the timeline).

Search options for editing item query

On the edit page, you can add items via the following fields:

  • Search for Keywords
  • Narrow by Specific Fields
  • Search by a range of ID#s
  • Search by Collection
  • Search by Type
  • Search by User
  • Search by Tags
  • Public/Non-Public
  • Featured/Non-Featured.

As well, plugins can add more search fields, such as:

  • Geolocation search
  • Search by Exhibit
  • Item Relations.

You can add items using one or any combination of these fields. For instance, if you know that the majority of the content for the timeline is contained in a single exibit you would want to select that exhibit in the corresponding dropdown. If you wanted to be sure you did not miss any relevant items that were not included in that exhibit, you may want to use the "Specific Fields" search to include any items mentioning the topic in their metadata that are not part of that exhibit. Or, you may want to search by a specific user if you only want to include that person's work. By adjusting the fields you can expand or narrow the scope of items included on your timeline.

Once you have filled in all the desired search fields, click "Search for items". This will add all relevant items to your timeline.

Timeline summary page

Timeline populated based on query

Each timeline will have a summary page (found at /admin/timeline/show/1 where 1 is the ID number of the timeline). Here you can see a preview of the timeline to confirm it is loading the correct items from the query; you can also view the public page of the timeline to see the same thing with its display settings and in your theme.

You can adjust the metadata and display settings with the "Edit Metadata" button. To further add or remove items from your timeline, you can adjust your query by clicking "Edit Item Query". If you click "Delete", you will delete the entire timeline and its metadata. To see the public view of your timeline, click "View Public Page".

Value formatting

You may need to manually edit some date or interval values to include items on your timeline to match ISO 8601 formats.

Use the following formats for dates, including dashes between values:

  • 2022
  • 2022-08 (year and month, no date)
  • 2022-08-18.

Use the following formats to add times to your date values:

You cannot omit the year while providing a month and/or day. You cannot supply ordinal dates (as in, 2000-175 for the 175th day of the year 2000).

Use the following formats for intervals with start and end points:

  • 2007/2008
  • 2007-03/2008-05 (Will appear in the timeline as "March 2007 - May 2008")
  • 2007-03-01T13:00:00Z/2008-05-11T15:30:00Z (Will appear in the timeline as "1 March 2007 13:00:00 +00:00 — 11 May 2008 15:30:00 +00:00").

You cannot supply a duration value.

Displaying your timeline

There are several different methods you can use to view and/or display your timeline. Timeline integrates with the Exhibit Builder plugin by adding a new Timeline block option to exhibit pages:

Admin view of timeline option in exhibit builder

You can also add a timeline to a page using Shortcodes.