It’s worth noting at the outset that I don’t know anything about generating ContentDM export files (partially because even the ContentDM documentation is proprietary, or at least hidden behind a login). But I do know that every time someone has sent me a cDM export file, it is in tab-delimited format (UPDATE: here is the Tab-delimited export documentation), which is basically a plain text spreadsheet. I gather these spreadsheets can be produced pretty easily so I think we can start by assuming you already have the spreadsheet and need to prep it for import into Omeka, which will be done in this tutorial using the CSV Import plugin. If you are not already familiar with how that plugin works, check out the documentation page at Omeka.org before continuing.

You probably need to use Excel

First, open the tab-delimited spreadsheet in Microsoft Excel. You will later save this file in CSV format. If you prefer using non-MS spreadsheet software, you are probably out of luck. As far as I know, neither OpenOffice/LibreOffice nor Apple’s Numbers have an equivalent ‘Text-to-Columns…’ functionality, which will be used in this process.

Remove unwanted and problematic rows/columns, Rename column headers

Once you have your spreadsheet open in Excel, go ahead and remove any ContentDM-specific administrative metadata, or anything else you don’t wish to carry over to Omeka during the migration. At this point, you should probably rename the column headings to something meaningful. This will help with the crosswalk step later.

Breaking out semicolon-delimited values

Next, you will want to check for columns having multiple entries within a single cell. At the very least, this will probably include the Subjects column (because archivists/librarians are never satisfied with assigning just one subject term… subject classification being the Lay’s potato chip of librarianship). By default, these multiple subjects will be separated by a semicolon (e.g. “Librarianship — Potato Chip Analogies; Librarianship — Puns; Librarianship — Personality Disorders;” ). Instead of copying each one of these entries into a new Subjects column, you can just use the “Data > Text to Columns…” feature in Excel. I recommend using a separate worksheet for this step as the new columns will overwrite your existing ones if you are not careful.

Getting the File Path URLs

So you’ve shaped up all the metadata on the spreadsheet. Now you need to define the path to the item file in ContentDM. This is probably the trickiest part to come up with on your own, especially if you are not so familiar with ContentDM. Basically, our starting point will be the cDM “Reference URL.” Those look something like this: http://images.ulib.csuohio.edu/u?/press,59. Assuming you have a whole column of Reference URLs, you need to run a Find and Replace to create your file path (again, I recommend doing this in a separate worksheet so you don’t accidentally overwrite important data). Let’s begin.

UPDATE: in ContentDM version 6+, ShowFile is replaced by GetFile. Adjust the following instructions as needed (i.e. in the first Find and Replace, swap out showfile.exe with getfile.exe).

Start with something like:
http://images.ulib.csuohio.edu/u?/press,59

FIND this:
u?/
… and REPLACE with this:
cgi-bin/showfile.exe?CISOROOT=/

Next, FIND this:
,
…and REPLACE with:
&CISOPTR=

So now we have something that looks like:
http://images.ulib.csuohio.edu/cgi-bin/showfile.exe?CISOROOT=/press&CISOPTR=59

This is a working file path that can be used by the CSV Import plugin to ingest the item file along with the metadata record.

In some instances, you might need to tweak this process. For example, if your ContentDM installation includes JP2 or TIF files (or some other unfriendly image format) but you don’t want the hassle of building a custom display wrapper into your Omeka theme, you can append some additional query string parameters to your file URL.

So if you want ContentDM to serve up a JPG instead of a JP2 (or other…) file, add this to your file column
&DMSCALE=100.00000&DMWIDTH=1600&DMHEIGHT=1600&DMX=0&DMY=0&DMTEXT=&REC=1&DMTHUMB=0&DMROTATE=0
…using this Excel function (where A2 is the first column/cell in need of appending):
=CONCATENATE(A2,"&DMSCALE=100.00000&DMWIDTH=1600&DMHEIGHT=1600&DMX=0&DMY=0&DMTEXT=&REC=1&DMTHUMB=0&DMROTATE=0")

Finally, you need to swap showfile with getimage in the file URL above by running one more find and replace in Excel.

So now, your file path looks like:
http://images.ulib.csuohio.edu/cgi-bin/getimage.exe?CISOROOT=/press&CISOPTR=59&DMSCALE=100.00000&DMWIDTH=1600&DMHEIGHT=1600&DMX=0&DMY=0&DMTEXT=&REC=1&DMTHUMB=0&DMROTATE=0

This will return a JPG file, which is pretty handy. These additional parameters will vary by installation and file type. I don’t know what all of the parameters are or even what each one does; only that this usually works. Again, this is a case where actual ContentDM documentation would be really handy. UPDATE: Keep in mind that this only works with image file types. For more details, check out the GetImage documentation.

Metadata Crosswalk

It’s usually a good idea to plan out your metadata crosswalk in advance, especially if you have multiple export files (and you should if your collection is bigger than a few hundred items; more on that later). Remember that Omeka – out of the box – only uses the first 15 Dublin Core elements. You may need to add a new Item Type or install Dublin Core Extended in order to find/create an appropriate home for your legacy/custom metadata in Omeka.

Batching

To avoid server timeouts, you should consider breaking your spreadsheets into manageable batches. I try not to import more than a few hundred items at a time, and even then one of the two servers involved is likely to timeout or throw an error or something. Keeping the batches small makes it easier to isolate problems, avoid import errors, and undo problematic imports.

Using the CSV Import Plugin

From here, just follow the standard instructions for using the CSV Import plugin.

Bugs, Known Issues, and Limitations

As of version 1.3, there are still some quirks. For example, your file path – that hideous long URL you worked so hard to create – will become the actual name of your imported/migrated file. In some instances, your files may be ingested sans file extension (e.g. .pdf, .jpg, .mp3), which can cause various headaches (though it’s worth noting that these files will generally display inline on your site, due to the way most Omeka themes handle media files, and will only break down when someone tries to download the file, in which case they would need to manually add the file extension). From time to time, you could have an import that hangs indefinitely, never finishing and never failing — and thus not easily “undo-able” (at least, the “Undo Import” button will not be visible). In such a case, you can manually create that button by entering the following URL pattern into your address bar:

http://[PATH TO YOUR OMEKA INSTALLATION]/admin/csv-import/index/undo-import/id/[IMPORT ID]

– this is on the plugin documentation page by the way, as are several other points in this tutorial.

One of the biggest limitations of the CSV import strategy is that you will probably have issues migrating compound objects and other multi-file items, primarily because of the way ContentDM formats the export file and serves compound objects online and partially due to limitations in the way the plugin works with Omeka. Basically, you need all the files for an item to be in the same row as all of the other item-level metadata (e.g. in columns like “File 1,” “File 2,” “File 3,” etc). And there is currently no way to use the CSV Import plugin to assign file-level metadata. For example, if you had a postcard in your ContentDM collection and it had distinct metadata for each side (say, for front.jpg and verso.jpg), along with general metadata for the object as whole, something is going to be lost in the migration without some serious elbow grease.

The Omeka Dev forums are the best place to report bugs, inquire about error messages, discuss workarounds, and submit patches. The general Omeka Forums are also great for more basic questions; happily, most questions get answered in fairly short order. Please do not post support questions here. Please do, however, feel free to leave general comments, suggestions for improvement, requests for clarification, etc.

IMAGE NOTE: poorly Photoshopped post image contains assets by multiple artists and designers, including the amazing “Bob” sketch from Matt Haley’s unreleased but totally awesome sounding Twin Peaks: Season 3 graphic novel.

Deco is a free theme for Omeka. Though I started working on an Omeka theme for use by a more general audience and without any particular motivation beyond having a lame sense of fun, as I got going, I realized it might be really useful for the group of social studies teachers with whom I’ve been working this past week. As part of a grant-funded workshop, the teachers needed to start their own WordPress- and Omeka-based websites (for use in their classrooms). As you might expect, none of the teachers had experience with such things. After an arduous 4 hour workshop in which the group got all of their hosting plans purchased and sites installed and configured, we kind of slowly came to a realization that there was still foundational work to be done. Though Omeka is quite user friendly, it’s still best managed (in a self-hosted environment that is), by users having at least some experience with and understanding of web publishing. (omeka.net is a great hosted alternative by the way, and works much like wordpress.com, but for various reasons was not right for our project). And so the scope of this little side project grew as I tried to anticipate some of the problems novice users might encounter.

For one, Omeka’s publicly available themes sometimes seem lacking when combined with certain plugins. Each of the available themes is quite nice on its own terms and perfect for building out by experienced users (in fact, this theme is built on the very excellent Berlin theme by Jeremy Boggs and Ken Albers), but even for those with a moderate amount of design and coding knowledge, changing things up can be daunting, requiring a lot of time querying the forums, and browsing the documentation. I knew that most of the teachers would be using a set of plugins that require additional styling and code insertion and so I tried to prepare the theme with as much plugin-specific styling and conditional templating I could so that they would not have to fool around too much. The most common needs should hopefully be addressed by the core templates and through the many configurable theme options

This is my first public theme and it’s been quite an experience thinking through all the possible use cases. I think I have accounted for the most common possibilities, but it’s possible something could still come up and present a problem: there could be errors to debug, display problems in older browsers, poorly formed functions, etc.. Thus, I’m calling this version 0.9, just to be safe, but I think it is certainly usable at this point. Nevertheless, the usual “no warranty” caveat applies.

Deco theme for Omeka

Designed for: Omeka Version: 1.3

Browser tested in: Internet Explorer 8+, and current versions of Firefox, Chrome, Safari, and Opera

License: GPL

Changelog:

• Dec 06 2010 — v. 0.9: initial release
• Jan 15 2011 — v. 0.9.5: updated for compatibility with Omeka 1.3 and new plugin releases, various bug fixes
• March 06 2011 — v. 0.9.6: added html5/flash video support, improved image gallery on homepage (now uses any featured item that has an image attached, randomized display), started cleaning up ugly code, various bug fixes and layout tweaks
• April 27 2011 — v. 0.9.6.1: added deco_display_rss() function to custom.php, fixed bug in Featured Exhibit function on homepage to detect if Exhibit Builder plugin was installed/activated, minor layout tweaks
• June 26 2011 — v. 0.9.6.2: removed show_untitled_items() function due to incompatibility with Omeka 1.4
• August 30, 2011 — v. 0.9.6.3: fixed minor bug in config.ini that was affecting some users

Unique Features:

• Featured Item slideshow on homepage (jQuery, Awkward Showcase)
• Lightbox effect for images on items/show (jQuery, FancyBox)
• Built in support for HTML 5 Video with Flash fallback (VideoJS, Flowplayer)
• “Edit this Item” button on items/show
• Add an RSS feed anywhere on your site using the deco_display_rss($feedUrl,$num) function (uses Zend RSS, note that using this function may lead to slower load times)
• Configurable theme options
  • stylesheet-switching with 4 designs in the initial version (plus a custom.css option for advanced users)
  • user-defined tagline
  • user-defined “About” text on the homepage
  • user-defined number of recent items to display on the homepage
  • toggle lightbox on items/show
  • toggle slideshow on homepage
  • toggle “Random Featured Collection” on homepage
  • toggle images with “Random Featured Collection” on homepage
  • toggle “Related Exhibits” on items/show
  • toggle theme credits in footer
• Built in support for common plugins
  • MyOmeka (user status in footer, CSS styles)
  • Exhibit Builder (CSS styles)
  • DocsViewer (ideal placement in items/show if user does not choose the default embed on items/show option)

Known Issues and Planned Improvements

• ISSUE: Conflict with Image Annotation plugin breaks the gallery and fancybox scripts.
• PLANNED IMPROVEMENT: Additional stylesheet choices (better, more varied)
• PLANNED IMPROVEMENT: Let users configure or at least turn off HTML5 video options in theme settings.

Download Deco, version 0.9.6.4 [GitHub]