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Save properties in a file called file-name.properties, where file name corresponds to the base file name. Filter out all files that end in .properties from the list of resources contained in a collection.
Attachments
Save attachement references in a file called file-name.attachments. Filter out all files that end in .attachments from the list of resoources in a collection. Note that attachments will appear as resources in the collection. This may or may not be a good thing. If undesired, resources can be moved to a shadow context with collection structures replicated from the resources. This isn't a very good solution either, since the whole point of this exercise is to make it easier to retrieve files from back up. Moving them to a different point in the directory structure doesn't make this any easier for an administrator. An alternative approach is to put attachments into an archive (zip, for example)It's not clear that collection properties are used in Sakai at this time, but clearly they could be useful. Since there is only one collection properties file in a given directory, it can be given a unique name, "collection.properties". As long as this file is filtered from the list of files in a directory, all will be fine.
A base implementation of ResourceProperties exists in the entity model. An FSProperties will be created to extend this implementation primarily to handle storage into and out of a .properties file.
Attachments
Sakai content hosting supports the concept of resources having attachments. These attachments (like MIME attachments) are separate objects (files) that are appended (or attached) to the main resource. Three approaches to file-based attachments are being considered:
Locally Referenced Files
Attachment objects exist as local resources in the same collection. Attaching is accomplished either via a file-name.attachments file, or via multi-valued property in .properties (favored). While this is a simple approach, it does mean that attachment objects will be visible in tools that list files in a collection. Does the resource tool show attachments as files?
Files in Collections
Attachment objects could be contained in a special collection as a child of the current collection. This is a bit ugly, since these sub-collections either needed to be treated specially or filtered out. However, this roughly corresponds to the way JSR-170 handles attached objects.
Files in an Archive
Attachment objects could be contained in an archive format (like zip). Some overhead is added getting them in and out of the archive format.
Identifiers
Content resources are identified by a file name. In most cases, this name will have a file extention separated by a period, from which the MIME type may be deduced (via an extention map). All files also have a metadata file associated with it named the same, with a file extension of .properties. These properties may optionally be cached in a database to allow faster access to them.
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