Renditions/Reviews/Thumbnails in WebDAV

Hi,

the CMIS TC is currently discussing how to expose thumbnails in their 
API. While listening to that discussion, I realized it would be trivial 
in WebDAV, based on link-typed properties and the DAV:expand-property 
REPORT.

So, the use case is: retrieve contents of a folder, and for each image 
in the folder, retrieve URLs + metadata for thumbnail images.

Solution:

1) New property x:preview-set, containing a set of DAV:href elements 
referencing HTTP resources representing the preview (thumbnail) resources.

2) The DAV:expand-property 
(<http://greenbytes.de/tech/webdav/rfc3253.html#rfc.section.3.8>) 
already allows getting the contents of a collection, while also 
expanding link-type properties.

Such as:

REPORT / HTTP/1.1
Host: www.webdav.org
Depth: 1
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx

<D:expand-property xmlns:D="DAV:">
  <D:property name="preview-set" namespace="extension-URI">
  </D:property>
</D:expand-property>

Note that this REPORT will also allow retrieving properties of the link 
targets, such as the thumbnail's dimensions.

BR, Julian

Received on Tuesday, 26 May 2009 18:49:26 UTC