R/dropbox_dir.r

In karthik/rDrop: Dropbox R interface.

#'Function to list contents of a Dropbox folder.
#'
#' If no folder is specified, it will only list contents of the root folder.
#' @param cred An object of class DropboxCredentials with Dropobox specific credentials.
#' @param path  The directory to list. Not yet implemented
#' @param verbose logical. FALSE returns a list with file names in root folder. TRUE returns a \code{data.frame} with the following fields: id, revision, rev, thumb_exists, bytes, path, modified, and is_dir
#' @param deleted logical. Default is FALSE. Set to TRUE to also list deleted files.
#' @param pattern an optional regular expression. Only file names which match the regular expression will be returned.
#' @param curl If using in a loop, call getCurlHandle() first and pass
#'  the returned value in here (avoids unnecessary footprint)
#' @param ... optional additional curl options (debugging tools mostly).
#' @return directory listing with file or folder names unless \code{verbose = TRUE} in which case a data.frame is returned.
#' @export dropbox_dir
#' @examples \dontrun{
#' dropbox_dir(db_cred)
#' dropbox_dir(db_cred, path='/specific_folder')
#' dropbox_dir(db_cred,path='/specific_folder', verbose = TRUE)
#' dropbox_dir(db_cred,path='/specific_folder', pattern='file', verbose = TRUE)
#' returns a dataframe with fields .id, revision, rev, thumb_exists, bytes, modified path, is_dir, icon, root, size, client_mtime, mimetype.
#'}
dropbox_dir <-
function(cred, path = character(), verbose = FALSE, 
         deleted = FALSE, pattern = NULL, curl = getCurlHandle(), ..., .checkIfExists = TRUE)
{
    if (!is(cred, "DropboxCredentials")) 
        stop("Invalid or missing Dropbox credentials. ?dropbox_auth for more information.", 
            call. = FALSE)
    
    url <- "https://api.dropbox.com/1/metadata/auto"
    if (length(path) && .checkIfExists && 
         !exists.in.dropbox(cred, path, is_dir = TRUE, ..., curl = getCurlHandle())) 
            stop("There is no such folder in your Dropbox", call. = FALSE)

    if (length(path) && grepl("/$", path)) {
            path <- str_sub(path, end = str_length(path) - 1)
    }

    url = getPath(path, url = url, cred = cred)
    
    metadata <- fromJSON(OAuthRequest(cred, url, list(include_deleted = deleted), 
                                      ..., curl = curl))
    
    names(metadata$contents) <- basename(sapply(metadata$contents, 
                                                `[[`, "path"))
                                                
    file_sys <- ldply(metadata$contents, data.frame)
    if (!is.null(pattern)) {
        matches <- str_detect(file_sys$.id, pattern)
        file_sys <- file_sys[matches, ]
    }
    if (!verbose) {
        return(file_sys$.id)
    } else {
        return(file_sys)
    }
}
# API documentation:
#   https://www.dropbox.com/developers/reference/api#metadata
# Issues: Fails with empty directories
# filename, revision, thumb, bytes, modified, path, and is_dir