Create a function that updates a folder tree based on the given restrictions
This functions returns a new function that will handle updating the folder
tree. It is the folder equivalent of
fileGetter() but functions
slightly different as it needs to handle expanded branches of the folder
hierarchy rather than just the content of a single directory at a time. The
returned function takes a representation of a folder hierarchy along with the
root to where it belongs and updates the tree to correspond with the current
state of the file system, without altering expansions etc.
dirGetter(roots, restrictions, filetypes, hidden = FALSE)
A named vector of absolute filepaths or a function returning a named vector of absolute filepaths (the latter is useful if the volumes should adapt to changes in the filesystem).
A vector of directories within the root that should be filtered out of the results
A logical value specifying whether hidden files should be returned or not
A function taking a list representation of a folder hierarchy along
with the name of the root where it starts. See
a description of the format for the list representation.