topic Re: Thumbnail Viewing -- Is this possible in Alfresco Archive

Thumbnail Viewing -- Is this possible

thaneshk — Mon, 06 Mar 2006 06:48:59 GMT

Suppose we are using imagemagick to convert an image to a thumbnail, is this possible.Could the image be converted and stored directly into the repository and file system, and in otherwords how do we manipulate the system so that we dont have to create thumbnail, then store it in repository and then

Re: Thumbnail Viewing -- Is this possible

kevinr — Mon, 06 Mar 2006 11:36:21 GMT

The Alfresco "Rules" functionality can be used to automatically generate thumbnails and add them to the repository. A couple of temporary files are created when imagemagick runs, but they are cleaned up by Alfresco.

You can currently use Templates to display those thumbnails as a dashboard view.

We do not yet have a dedicated Thumbnails view, but as i say it is easy enough to use Alfresco to generate them.

Here is an example using rules to generate thumbnails:
http://www.alfresco.org/forums/viewtopic.php?p=4301

Thanks,

Kevin

Re: Thumbnail Viewing -- Is this possible

derek — Tue, 07 Mar 2006 11:13:42 GMT

Hi,

I see your point. The answer is "unfortunately not". Consider the nature of a ContentTransformer. It has to transform content from a ReadableByteChannel and output it to a WritableByteChannel. Some transformers, especially those that run in a process outside of our system, cannot deal directly with streams. This is true of the ImageMagick convert executable that we use. Other transformers (ImageMagick and OpenOffice) require files with well-known extensions. But we only have streams and are therefore compelled to create temporary files.

So why not just pass files in and out of the ContentTransformer? Because the content storage system is designed to be extendable. We can bolt on a database store, a tape-drive store, a zip-file store and any other number of remote content stores. The lowest common denominator is an IO channel.

Regards