JSF component + URL filter to download file attachments

The nuxeo tag library need an an upgrade for the outputFile and outputImage components and matching URL filters to be able to generate / handle URLs to directly access the content of a blob. Sample expected URLs are:

http://server.domain:port/nuxeo/nxdoc/demo/a8865360-a076-4a31-890d-6d1bb14f1e1b/download_blob/file/content/3/filename.doc

or

http://server.domain:port//nuxeo/download_blob/demo/a8865360-a076-4a31-890d-6d1bb14f1e1b/file/content/3/filename.doc

where:

• 'file' is the schema name of the blob to download
• 'content' is the field name of the blob to download
• '3' is the index of the blob to download in case 'file.content' is a complex field (optional)
• 'filename.doc' is the filename of the blob if any (optional)

Why we need a GET URL and not a js postback (like h:commandLink component):

• we will need to generate HTML tags such as <img src="/my/get/url/to/image.png" alt="image title"/> so that browsers can download blobs to be used as images (for thumbnails of content and so).
• have meaningful URL so that google can index attached files (PDF, doc, ...) to be ready the day nuxeo 5 wil be used for web content management.

We also need similar URL filters and JSF tags for the "edit online" and "pdf preview" links.