All folder must have a name. No '.' or '/' chars are permitted
TODO: unhook a child folder.
Add a child folder. The child cannot 'overlap' with others in the tree of the same type. Circular references across a tree of virtual folders are detected and trapped.
Return a file representation of the given path. If the path-head does not refer to an immediate child folder, and does not match a symbolic link, it is considered to be unknown.
Return the (short) name of this folder
Return the (long) name of this folder. Virtual folders do not have long names, since they don't relate directly to a concrete folder instance
Add a child folder. The child cannot 'overlap' with others in the tree of the same type. Circular references across a tree of virtual folders are detected and trapped.
Add a set of child folders. The children cannot 'overlap' with others in the tree of the same type. Circular references are detected and trapped.
Unhook a child folder
Add a symbolic link to another file. These are referenced by file() alone, and do not show up in tree traversals
Add a symbolic link to another folder. These are referenced by folder() alone, and do not show up in tree traversals
Iterate over the set of immediate child folders. This is useful for reflecting the hierarchy
Return a folder representation of the given path. If the path-head does not refer to an immediate child, and does not match a symbolic link, it is considered unknown.
Return a file representation of the given path. If the path-head does not refer to an immediate child folder, and does not match a symbolic link, it is considered unknown.
Clear the entire subtree. Use with caution
Returns true if all of the children are writable
Returns a folder set containing only this one. Statistics are inclusive of entries within this folder only, which should be zero since symbolic links are not included
Returns a subtree of folders. Statistics are inclusive of all files and folders throughout the sub-tree
Sweep the subtree of mountpoints, testing a new folder against all others. This propogates a folder test down throughout the tree, where each folder implementation should take appropriate action
Close and/or synchronize changes made to this folder. Each driver should take advantage of this as appropriate, perhaps combining multiple files together, or possibly copying to a remote location
Throw an exception
LinkedFolder is derived from VirtualFolder, and behaves exactly the same in all but one aspect: it treats mounted folders as an ordered list of alternatives to look for a file. This supports the notion of file 'overrides', whereby "customized" files can be inserted into a chain of alternatives.
(overridden folders are not currently supported)