Download PDF

On this page…
Create an Omeka Plugin Target
Create an Omeka API (Beta) Target
Omeka Element Sets
Omeka Item Types
Manage Omeka Field Mapping
Further Resources

Institutions using Forum can create a publishing target for an Omeka collection website. You can create an Omeka API target using a metadata schema of your choice to publish multimedia to your collections. You can create an Omeka Plugin target to publish only images and use the Dublin Core metadata schema for your or collections.

Create an Omeka Plugin Target

This target can be added to an existing project or setup for a new project. Forum supports publishing to sites built on (relying on your institution’s hosted server) or (Omeka’s hosted solution).

For users, there is an updated plugin that is compatible with new PHP versions. This plugin can be downloaded from Github at We recommend uninstalling the previous plugin version, and then following the installation instructions provided by Omeka at For users, the original version of the plugin is available in Omeka Admin under the Plugins section.

*Note: Prior to January 2018, JSTOR Forum was called “Shared Shelf”. The name of the plugin does not yet reflect the transition to the new name.

While setup for both types of Omeka sites is identical within the Forum Administrative Tools, the steps will be slightly different depending on your Omeka configuration.

To create an Omeka Plugin publishing target:

  1. Install the plugin:
  2. From Omeka Admin Plugins section, click Configure.  You will be asked to create a default token/password (Authorization Token). The token is one of your choosing, but password best practices are recommended. You can find your set token anytime by following these steps.OmekaSShelfPluginToken
  3. Create a collection in Omeka to link to Forum for publishing records. If a collection is not created in Omeka, a target cannot be selected through the Admin Tools. Consult Omeka’s documentation about collections at for instructions on creating collections. In order to proceed with the remaining steps, your collection must be set to Public when configuring your collection in Omeka Admin.
  4. In the Forum Administrative Tools, navigate to the Targets tab. Click the New button, then select “Omeka Plugin publishing target” from the dropdown menu.
  5. Enter the domain URL of your Omeka site and the token you created when configuring the plugin.
  6. Click Next to continue, and then select your Omeka site collection from the dropdown menu; click Finish to create the target. If your collection does not appear in the dropdown, this may mean it is not configured as Public in Omeka Admin. Set the collection to Public then try creating the publishing target again in the Forum Administrative Tools.
  7. After the Omeka plugin publishing target is created, select the target from the list and click the Manage Mappings button.
  8. Map your project fields so they are visible to end users.
    • The Omeka plugin uses Dublin Core as the default metadata standard for all collections. Your project fields may be mapped to these 15 fields however you prefer.
    • You have the option to use prefixes when mapping multiple fields to a single default. You may also establish fields required for publishing to your Omeka target.

Create an Omeka API (Beta) Target

*Important Note: The Omeka API is currently in beta testing as more knowledge is required on the functionality. If your institution is interested in setting up an Omeka API target during this phase, please be aware that a successful setup cannot be guaranteed. For more information, please contact

If using (the locally installed version of Omeka), we suggest publishing with the Omeka API publishing target. Benefits to using the Omeka API, as opposed to the plugin for publishing, includes the ability to publish multimedia content to your Omeka collection and utilize other plugins to better manage the user experience of your local content. Due to a limitation of, this  beta version of the Omeka API publishing target only supports publishing to collections. system configuration:

  1. Login to admin and disable the file upload validation.
    • Navigate to Settings > Security
    • Select the option “Disable File Upload Validation”
  1. Increase media size on Omeka server
    • Note: The default media size is 16M in a php.ini file. You will need to increase the number to be bigger than the size of the largest files processed in your project(s). When deciding the maximum size to be handled by the Omeka server, please also consider the server’s capacity.
    • The below uses “128M” as an example.
    • The php.ini file is located at /etc/php5/apache2
    • Update the file and set it to:
      • memory_limit = 128M (Maximum amount of memory a script may consume)
      • upload_max_filesize = 128M (Maximum allowed size for uploaded files.)
      • post_max_size = 128M (Maximum size of POST data that PHP will accept)
  1. Restart Apache php server: /etc/init.d/apache2 restart


To set up an Omeka API publishing target:

  1. Log into admin.
    • Navigate to Settings > API, and check the box to Enable API.
    • Navigate to Users > select a user > Edit User > API keys.
      • Even though Omeka settings require admins enabling a key through the user, there are no constraints on users’ abilities to catalog and publish to the Omeka target via Forum.
    • To set up an API key, enter a label identifying the key (e.g. Forum key) and configure to auto-generate a new API key.
      • The same API key can be used for unlimited Forum projects, and does not need to be regenerated each time you set up a new Omeka target.
      • Refer back to the API key page to copy and paste the key when setting up a new Omeka target in the Admin Tools.
    • Navigate to Collections to create your collection name.
      • Note: Collections no longer require being set to Public for enabling, so you can set up a Private collection and publish content for further management in Omeka before making Public and available to your users.
  2. Login to the Admin Tools.
    • Navigate to Targets, and select New.
      • In the dropdown selection box, choose the Omeka API (beta) Publishing Target type.
      • Following the steps of the dialog window, enter the Omeka site’s URL (e.g.
      • Using the API key copied from Omeka admin, paste it in the window. If there is an error with the URL or key, the dialog window will generate an error to let you know. Try again or contact for assistance.
      • Follow the steps to enable the desired Element Sets and Item Types (see below for more information on Element Sets and Item Types).
      • Select Create and your new target will appear in your list of publishing targets for your selected project.
      • Select the target to edit any settings, including updating the API key, and save any changes made.
      • Select the target to apply the field mappings (see below for more information on Mapping).
      • The target is enabled and ready to begin receiving published content. Remember any edits made to the target after items have been published requires those items to be re-published to allow the changes be seen by end users.
  3. Contact to share your Omeka URL, API key, collection name, and Forum project name so Artstor may enable the collection behind our firewall for troubleshooting requests.

Omeka Element Sets

Element Sets serve as the metadata schema to which project fields can be mapped. In early versions of Omeka, Dublin Core was the default element set supported for all collections. Now, Omeka supports any metadata schema that has been enabled as a plugin by members of the Omeka user community. The default is to use Dublin Core, but Omeka admins may enable other elements sets such as VRA Core, PB Core, Social Media, and more. Check out the support pages for ( to learn more about how to enable and use Element Sets.

To enable and use Element Sets in Forum:

  1. When creating a new Omeka API target, navigate to the second screen of the dialog window.
    • Dublin Core is the default element set and will appear at the top of the list, followed by any additional element sets that had been enabled.
    • Hold control or shift and check the boxes to enable multiple element sets. OR deselect enabled element sets to select only one. At least one element set is required to proceed with creating the Omeka target.
    • Save the changes by navigating to the next screen of the dialog window.
    • Element sets may be edited later by selecting the Omeka API target from the list under the Targets tab and clicking Edit.
      • Select or deselect any element sets that you have enabled through Omeka admin and save the changes.
    • Your element set’s fields will appear as target fields to which you can map project fields.

Omeka Item Types

Though Element Sets are required for mapping the fields to be published to Omeka, Item Types are optional and can be used as supplemental fields for mapping specific data. Item Types may include Moving Images, which incorporates descriptive fields for video content, and Still Images. Omeka has a set of pre-built Item Types, as well as those created by members of the Omeka user community, which you can contribute to in creating local Item Types. Check out the support pages for ( and to learn more about how to enable, use, and create Item Types.

To enable and use Item Types in Forum:

  1. When creating a new Omeka API target, navigate to the third screen of the dialog window.
    • A list of Omeka-built item types will be available, along with any locally created item types set up in the Omeka admin.
    • Hold control or shift and check the boxes to enable multiple item types. OR deselect enabled item types to select only one or none.
    • Save the changes by navigating to the next screen of the dialog window.
    • Item types may be edited later by selecting the Omeka API target from the list under the Targets tab and clicking Edit.
      • Select or deselect any item types that you have enabled through Omeka admin and save the changes.
    • Your item sets fields will appear as target fields to which you can map project fields.

Manage Omeka Field Mapping

As with any publishing target, fields from your project must be mapped in order to display. For the Omeka Plugin, fields must be mapped to the Dublin Core schema. The Omeka API now supports additional mapping features through the enabling of multiple Element Sets and Item Types. As a result, the target fields in the mapping window will now identify the source element set or item type for the field. For example, if both Dublin Core and VRA Core element sets have been enabled for the Omeka collection, the mapping window will show two Title fields, separated only by the element set or item type indicated in parentheses (e.g. Title (Dublin Core) versus Title (VRA Core)). The more element sets and item types enabled, the more target fields that are available for mapping. However, please note that Forum fields can only map to one field, so if you have one Title field in the project, then you must choose between the Dublin Core or VRA Core element sets for mapping.

For both Omeka Plugin and Omeka API targets, the use of prefixes, displayable, searchable, and required fields is supported.

To map your fields:

  1. In the Targets tab, select the Omeka collection name, then click Manage Mappings.
  2. In the dialog window, the top portion of the box will be the Target Fields. Scroll down the list to see an Unmapped folder and list of fields ready to be mapped.
  3. From the unmapped fields list, grab the green icon with your cursor to drag and drop the unmapped field onto the corresponding target field at top for mapping.
  4. Repeat until all desired fields are mapped for publishing. (See below for a suggested arrangement on how the mappings should match.)

Once you have dragged and dropped your mappings, click Save.


Whether mapping fields for an Artstor target or an Omeka target, it’s always important that you save the mappings first, then go back to edit the prefixes, displayable, searchable, and required fields after. Otherwise, making changes to mappings and prefixes, etc., at once will not successfully save.

To add prefixes, or change the displayable, searchable, and required settings:

  1. After the fields have been mapped and saved, re-open the Manage Mappings window.
  2. Double click on the desired field to open the edit window.
  • In this dialog window, you may enter a prefix which will appear as part of the field label. Include a space after the prefix to add a space between the prefix and the displayed data, e.g. “Longitude: 30°E” instead of “Longitude:30°E”.
  • The Displayable checkbox impacts whether the field is displayed among the data in Artstor.
  • The Searchable checkbox impacts whether the field content is searchable in Artstor.
  • The Required checkbox impacts whether catalogers can publish a record with data missing from a particular field.

Further Resources

A detailed comparison of the two versions of Omeka is here.

Resources for

Detailed installation instructions by a digital humanities scholar.

Development, releases and tutorials: Documentation and GitHub.

Resources for

Help site:

Contact form:

To see what others have done with the Omeka plugin, take a look at our list of Omeka sites built by users.