Extending Omeka with Plugins

On Tuesday we did a very brief introduction to the basic features in Omeka, including the general site configurations, configuring themes, and creating items, pages, and exhibits. This is enough to get started with Omeka, but most of you will want to do more.

The way to extend the functionality or change the appearance of an Omeka site will require knowing how to add plugins and themes to your installation. To do so, you will need to follow these steps:

  1. Review the available plugins and themes on the Add-ons page on the Omeka site. While you are reviewing each add-on, it is important to consider the minimum version of Omeka for which the add-on is created. You have installed the most recent version of Omeka, which is 2.4, so you need to be sure that your choices are created for at least version 2.0. All of those details are on the individual page for the add-on.
  2. When you find an add-on that you would like to use, download it to your hard drive. The download will be a zip file that contains all the files that make up the plugin.
  3. Follow the directions provided by Reclaim to use the File Manager in your CPanel to upload the zip file to the server and then expand it on the server. Plugins will go in the plugins directory in your Omeka installation, and themes will go in the themes directory in your installation.
  4. Once you have uploaded the add-on to the server and expanded it, then you can go to the administrative interface of your Omeka installation to install and configure your plugins and themes.
  5. Most people will need also to consult the documentation for the plugins that they install to learn how they work. Plugins that have been developed by the RRCHNM Omeka team are documented on the Omeka site under the heading “Working with Omeka Plugins.”

Selecting the Right Plugin for your Work

Knowing how to upload and and install plugins and themes is only half the battle. Selecting the correct plugin for your work, is really the important thing. Here are some suggestions:

Bulk Item Creation

Sometimes creating items by hand can be tedious, especially if are using existing data sets or if you have many items with common metadata values. As a result, you may consider some alternate routes to create many items at once.

  • CSVImport (Documentation) allows you to use a CSV file to create lots of items quickly. Remember to use a separate sheet/file for each item type. You can import files from URLS that point to publicly available files. This plugin requires a background process to ingest the CSV file. To use it with Reclaim Hosting, you will need to edit your config.ini file to specify the path for PHP-CLI. There clear instructions on how to do this from Reclaim.
  • Dropbox (Documentation) allows you to circumvent the limits on the size of the web browser file-upload process by providing a place on the server to upload your files. Use your file manager to upload the files, then they will be available for attachment to items in the Omeka interface. When you install the plugin, it will create a folder for files with in the plugin folder. You will have to set the permissions for that fold to make it writable. There are clear directions in the documentation for the plugin.
  • Omeka API Importer (Documentation) allows you to move content from one Omeka site to another (for Omeka sites that are version 2.1 or greater).

File Viewers

When you are creating items, you can attach many kinds of files to your metadata. Some of those file types require the use of plugins to make the files viewable within your item or exhibit pages (rather than having them appear as a link to a file that must be downloaded to be viewed.

  • PDF Embed places a PDF viewer on the page.
    • PDFText (Documentation) allows you to extract OCR’ed text from your PDF and make it available to Omeka’s search engine.
  • HTML5 Media allows you to view and play audio and video files

Organizing Content

Organizing content in Omeka is an important activity that is helped by the structure of Omeka as a content management system. Right out of the box items can be grouped in collections, or tied together with tags, but most projects would benefit from the articulation of more relationships. The following plugins allow you to make those connections.

  • Item Relations (Documentation) allows you to articulate the relationship between individual items using a set vocabulary of kinds relationships.

These plugins allow you to use controlled vocabularies to describe your items. These are helpful for reducing errors in your data entry and in making your data interoperable with other data set that employ the same controlled vocabularies. Also, these plugins facilitate creating linkages among all of the items that share the same values within a particular metadata field.

  • Library of Congress Suggest (Documentation) allows you to assign a Library of Congress controlled vocabulary to individual metadata fields (most frequently Subject).
  • Getty Suggest allows you to assign any of the Getty Research Institute controlled vocabularies to individual metadata fields.
  • Simple Vocab (Documentation) allows you to create your own controlled vocabulary and assign it to a metadata field. The result is that the field’s text box is replaced by dropdown menu from which an Omeka user can select a value. You may create as many controlled vocabularies and assignments as you wish.
  • Search By Metadata (Documentation) allows you to make the values in a metadata field a link, then when the end user clicks on that link she gets a browse list of all the items that share that value in that field. In combination with any of the controlled vocabulary plugins, Search By Metadata enables you to create a powerful network of hyperlinks amongst your content.

Community Contributions

Some kinds of projects are created to engage with users through a collecting portal or through many types of commenting.

  • The Contribution Suite is designed to allow end users to contribute stories or files to your Omeka site. Those contributions then become items within the site, and can be published (or not) by the site administrator. The suite calls for the installation of four plugins that need to be installed and configured in the order that they are listed below.
    1. Guest User (Documentation)
    2. Contribution (Documentation)
    3. Record Relations (Documentation)
    4. User Profiles (Documentation)
  • Commenting (Documentation) attaches a comment form to the end of an item, a page, or an exhibit. There are a number of options for deterring spammers if you choose not to moderate your comments.
  • Hypothes.is makes it possible for you to paste javascript in to the header file for the theme [e.g. /themes/berlin/common/header.php] to add it to your site. Soon there will be an annotation plugin that will insert the javascript into the theme for you.

Geospatial Work

There are a number of options for doing geospatial work with Omeka. Some of them are very simple and others are more complex.

  • Geolocation (Documentation) allows you to geolocate individual items on a Google map. Then, you can use that map as a way to browse your items on your site. Also, you can add a map that displays a specific group of items to an exhibit page. It is not possible to insert a georectified map or to draw on the map.
  • Neatline (Documentation) allows you to use a georectified historical map as a canvas for attaching items and laying interpretation. The documentation for Neatline asks that you run Geoserver, but that is not necessary. Lincoln Mullen has written a very clear blog post about how to get around that requirement: “Using Neatline without GeoServer”. Finally, Neatline works nicely with the Astrolabe theme.
  • Curatescape (Documentation) allows you to “curate the landscape by creating stories and tours. In order to make the plugins and themes work, you need to edit name of the plugin and theme folders to remove the word master so that the folder only includes the name of the plugin or theme after you download it.
  • Finally, you can embed visualizations from other tools (TimelineJS, StoryMapJS, CartoDB) in Simple Pages or in exhibit pages. Don’t forget to uncheck “Enable HTML Filtering” in your site’s Security Settings so that Omeka doesn’t strip out the code for your embed. When using embeds with Exhibit Builder, you will need to select the text block and then use the HTML editor to paste in the embed code.