[GUI Plugin] Overdrive Link

To search for books at Overdrive first highlight the desired book entries within Calibre and the choose Search Overdrive for selected books... from the plugin’s menu. Searches can take a while and so are run as jobs. After the search completes a summary of results is shown and an identifier is added to the Calibre book metadata for each match found to provide a link back to the Overdrive lending library page for that book. These links can be later used to open the web page for the book at the Overdrive lending library, either through the plugin’s menu or the book details panel.

Only one link per book will be shown under Ids: in the book’s details, corresponding to the highest priority library from which the book is available. A plus sign after the library name indicates that the book is also available from other libraries (or in other editions) and the additional links can be found in the Overdrive Link plugin menu.

The plugin supports multiple Overdrive libraries. Individual libraries and their relative priority are set in the plugin’s configuration. The default configuration contains some sample Overdrive libraries that can be enabled for searching. Additional libraries can be added as needed using the (+) icon. Each library is identified by its host name (e.g.: freelibrary.lib.overdrive.com) and a short name for the user interface (e.g.: Freelib). Configured libraries will only be used for searching and unlinking if they are enabled in the configuration by checking in last column.

The host name for an Overdrive library can be found by examining the address bar after surfing to the library’s web site.

The plugin works by first searching the main Overdrive website (search.overdrive.com) for matching e-books using the primary (first) author of the selected Calibre books. The search results are then matched against the selected books. Matched books are checked against each configured Overdrive library to see if copies are available from that library and if so a link is created.

Fuzzy matching is used to detect matches even when there are minor differences. The book matching process is not exact and may sometimes result in missing possible matches or association of the wrong books. A configurable confidence parameter controls the strictness of the matching process. In matching it is generally assumed that a colon (‘:’) in a title separates the main title from an optional subtitle and a vertical bar (‘|’) separates alternate titles for the same book.

There are some books available at individual libraries that do not show up when searched for at the main Overdrive site. These will not be discovered by this plugin. In addition, some searches return server errors from Overdrive. The plugin handles some common cases of this.

Links are stored in Calibre as identifier metadata. The format is ‘odid:uuid@host’ where uuid is the 36 character identifier used by Overdrive to identify an edition of a book and host is the host name of the specific Overdrive library. If the book is available in multiple editions or from multiple libraries there will be additional uuid-host pairs, separated by ampersands. For example:

A simple search for identifiers:"=odid:" can be done to find all books in Calibre that have an Overdrive link. A search for identifiers:"=odid:freelibrary" will show only books available at that library. A set of these searches is available through the plugin’s menu.

The Overdrive Link plugin contains an imbedded metadata plugin, Overdrive Link Helper, which provides the clickable links in the book details panel. This helper can be disabled in the main plugin’s configuration if this feature is not desired.