Institutions using Shared Shelf may 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 omeka.org collections. You can create an Omeka Plugin target to publish only images and use the Dublin Core metadata schema for your omeka.net or omeka.org collections.
Create an Omeka Plugin Target
This target can be added to an existing Shared Shelf project or set up for a new project. Shared Shelf supports publishing to sites built on omeka.org (relying on your institution’s locally-hosted server) or omeka.net, (Omeka’s hosted solution). While set-up for both types of Omeka sites is identical on the Shared Shelf end, the steps will be slightly different on the Omeka end.
- When building a locally-hosted Omeka.org site, install Omeka and the Shared Shelf Link plugin. Instructions for installing and managing plugins can be found on Omeka’s Managing Plugins page. For an Omeka.net site, the plugin is already included in the installation, but you will need to configure it in the Omeka admin page.
- Upon installation, you will be asked to create a default token/password (Authorization Token) on the Shared Shelf plug-in page. Password best practices are recommended.
- To find the token later, click “Configure” on the Shared Shelf plugin button from the list of plugins on your Omeka Admin site.
- Create a collection in Omeka to link Shared Shelf for publishing records. If a collection is not created in Omeka, a target cannot be selected through the Shared Shelf Admin tool. Consult Omeka’s Managing Collections page for instructions on creating collections.
- Contact email@example.com with your Omeka domain URL (e.g. http://yoursite.omeka.net) and token to enable the site for troubleshooting. Simultaneously, you may set up the Omeka target in Shared Shelf Admin.
- In the Admin Tool, navigate to the Targets tab.
- Click the New button, then select “Omeka publishing target” from the dropdown menu.
- Enter the domain URL of your Omeka site and the token you created when installing the Shared Shelf plugin.
- To find or reset the token, navigate to the Omeka Admin page, go the Plugin Settings page, and click “Configure” on the Shared Shelf plugin button from the list.
- Click Next to continue, and then select your Omeka site collection from the dropdown menu; click Finish to create the target.
- Select the Omeka target from the list and click the Manage Mappings button.
- Map your project fields so they are visible to end users.
- Omeka uses Dublin Core as the default metadata standard for all collections. Your Shared Shelf 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 firstname.lastname@example.org.
If using omeka.org (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 plug-ins to better manage the user experience of your local content. Due to a limitation of omeka.net, this beta version of the Omeka API publishing target only supports publishing to omeka.org collections.
Omeka.org system configuration:
- Login to Omeka.org admin and disable the file upload validation.
- Navigate to Settings > Security
- Select the option “Disable File Upload Validation”
- 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 Shared Shelf 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)
- Restart Apache php server: /etc/init.d/apache2 restart
To set up an Omeka API publishing target:
- Log into Omeka.org 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 Shared Shelf.
- To set up an API key, enter a label identifying the key (e.g. Shared Shelf key) and configure to auto-generate a new API key.
- The same API key can be used for unlimited Shared Shelf collections, 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 Shared Shelf admin.
- 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.
- Login to Shared Shelf Admin.
- 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. http://yoursite.omeka.org).
- 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 email@example.com 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.
- Navigate to Targets, and select New.
- Contact firstname.lastname@example.org to share your Omeka URL, API key, collection name, and Shared Shelf 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 Shared Shelf 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 omeka.org (http://omeka.org/codex/Managing_Element_Sets_2.0) to learn more about how to enable and use Element Sets.
To enable and use Element Sets in Shared Shelf:
- 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 sets fields will appear as target fields to which you can map Shared Shelf 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 Omeka.org (http://omeka.org/codex/Managing_Item_Types_2.0 and http://omeka.org/codex/Managing_Item_Type_Elements) to learn more about how to enable, use, and create Item Types.
To enable and use Item Types in Shared Shelf:
- 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 Shared Shelf fields.
Manage Omeka Field Mapping
As with any publishing target, fields from your Shared Shelf 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 Shared Shelf 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:
- In the Targets tab, select the Omeka collection name, then click Manage Mappings.
- 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.
- 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.
- 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:
- After the fields have been mapped and saved, re-open the Manage Mappings window.
- 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 the Artstor Workspace or Shared Shelf Commons.
- The Searchable checkbox impacts whether the field content is searchable in the Artstor Workspace or Shared Shelf Commons.
- The Required checkbox impacts whether catalogers can publish a record with data missing from a particular field.
A detailed comparison of the two versions of Omeka is here.
Resources for omeka.org:
Detailed installation instructions by a digital humanities scholar.
Resources for omeka.net:
Help site: http://info.omeka.net/
Contact form: http://info.omeka.net/contact/
To see what others have done with the Omeka plugin, take a look at our list of Omeka sites built by Shared Shelf users.