diff --git a/R/add_case.R b/R/add_case.R
new file mode 100644
index 0000000..87b210d
--- /dev/null
+++ b/R/add_case.R
@@ -0,0 +1,25 @@
+###########################################################################
+
+# Add case variable
+
+add_case <- function(data, cutoff = 20) {
+# TODO: What is the best choice for the cutoff here?
+
+  data$timediff <- as.numeric(diff(c(data$date.start[1], data$date.start)))
+  data$case <- NA
+  j <- 1
+  pb <- utils::txtProgressBar(min = 0, max = nrow(data), initial = NA, style = 3)
+
+  for (i in seq_len(nrow(data))) {
+    if (data$timediff[i] <= cutoff) {
+      data$case[i] <- j
+    } else {
+      j <- j + 1
+      data$case[i] <- j
+    }
+    utils::setTxtProgressBar(pb, i)
+  }
+  data$timediff <- NULL
+  data
+}
+
diff --git a/R/add_metadata.R b/R/add_metadata.R
new file mode 100644
index 0000000..e69de29
diff --git a/R/add_trace.R b/R/add_trace.R
index 4425373..78937b7 100644
--- a/R/add_trace.R
+++ b/R/add_trace.R
@@ -107,3 +107,68 @@ add_trace <- function(data, glossar_dict) {
   out
 }
 
+###########################################################################
+
+# Add trace for moves
+
+add_trace_moves <- function(data) {
+
+  pbapply::pboptions(style = 3, char = "=")
+
+  trace_max <- max(data$trace, na.rm = TRUE)
+
+  #subdata_art <- split(data, ~ artwork)
+  subdata_case <- split(data, ~ case)
+
+  #subdata_list <- split(data, ~ artwork + case)
+  # --> does not work with complete data set
+  cat("Splitting data...", "\n")
+  subdata_list <- pbapply::pblapply(subdata_case, split, f = ~artwork)
+  subdata_list <- unlist(subdata_list, recursive = FALSE)
+
+  cat("Adding trace...", "\n")
+  subdata_trace <- pbapply::pblapply(subdata_list,
+        function(x) {
+          trace_max <<- trace_max + 1
+          add_trace_subdata(x, max_trace = trace_max)
+        }
+      )
+
+  out <- dplyr::bind_rows(subdata_trace)
+  out <- out[order(out$fileId, out$date.start, out$timeMs.start), ]
+  rownames(out) <- NULL
+
+  # Make trace a consecutive number
+  out$trace <- as.numeric(factor(out$trace, levels = unique(out$trace)))
+  out
+}
+
+
+add_trace_subdata <- function(subdata, max_trace) {
+
+  if (nrow(subdata) != 0) {
+
+    if (length(stats::na.omit(unique(subdata$trace))) == 1) {
+      subdata[subdata$event == "move", "trace"] <- stats::na.omit(unique(subdata$trace))
+    } else if (length(stats::na.omit(unique(subdata$trace))) > 1) {
+      for (i in 1:nrow(subdata)) {
+        if (subdata$event[i] == "move") {
+          if (i == 1) {
+            subdata$trace[i] <- stats::na.omit(unique(subdata$trace))[1]
+          } else {
+            subdata$trace[i] <- subdata$trace[i - 1]
+          }
+        }
+      }
+    } else if (all(is.na(subdata$trace))) {
+      for (i in 1:nrow(subdata)) {
+        subdata$trace[i] <- max_trace
+      }
+    }
+
+  } else {
+    warning("subdata has nrow = 0")
+  }
+  subdata
+}
+
diff --git a/R/close_events.R b/R/close_events.R
index 38b4cec..87929dc 100644
--- a/R/close_events.R
+++ b/R/close_events.R
@@ -9,14 +9,14 @@ close_events <- function(data, event = c("move", "flipCard", "openTopic", "openP
       actions <- c("Transform start", "Transform stop")
       idvar   <- c("fileId", "folder", "eventId", "artwork", "glossar")
       drop    <- c("popup", "topicNumber", "trace", "event")
-      ncol    <- 16
+      ncol    <- 17
 
     },
     "flipCard" = {
       actions <- c("Show Info", "Show Front")
       idvar   <- c("fileId", "folder", "trace", "artwork", "glossar")
       drop    <- c("popup", "topicNumber", "eventId", "event")
-      ncol    <- 16
+      ncol    <- 17
 
     },
     "openTopic" = {
@@ -24,7 +24,7 @@ close_events <- function(data, event = c("move", "flipCard", "openTopic", "openP
       idvar   <- c("fileId", "folder", "eventId", "trace", "glossar",
                    "artwork", "topicNumber")
       drop    <- c("popup", "event")
-      ncol    <- 18
+      ncol    <- 19
 
     },
     "openPopup" = {
@@ -32,7 +32,7 @@ close_events <- function(data, event = c("move", "flipCard", "openTopic", "openP
       idvar   <- c("fileId", "folder", "eventId", "trace", "glossar",
                    "artwork", "popup")
       drop    <- c("topicNumber", "event")
-      ncol    <- 18
+      ncol    <- 19
 #   TODO: Should topicNumber maybe also be filled in for "openPopup"?
 
     }
diff --git a/R/create_eventlogs.R b/R/create_eventlogs.R
index 72c7578..0a3231f 100644
--- a/R/create_eventlogs.R
+++ b/R/create_eventlogs.R
@@ -5,14 +5,12 @@
 #'
 #' @param data Data frame of raw log files created with `parse_logfiles()`.
 #' See `?parse_logfiles` for more details.
-#' @param xmlfiles Vector of names of index files, often something like
-#' `<artwork>.xml`.
 #' @param xmlpath Path to folder where XML definitions of artworks live.
 #' @return Data frame.
 #' @export
 #' @examples
 #' # tbd
-create_eventlogs <- function(data, xmlfiles, xmlpath) {
+create_eventlogs <- function(data, xmlpath) {
 
   if (!lubridate::is.POSIXt(data$date)){
     cat("########## Convertion variable `date` to POSIXct ##########", "\n")
@@ -24,11 +22,11 @@ create_eventlogs <- function(data, xmlfiles, xmlpath) {
   dat <- subset(data, !(data$event %in% c("Start Application",
                                         "Show Application")))
 
-  # Create glossar dictionary ##############################################
-  cat("\n########## Creating glossar dictionary ##########", "\n")
   artworks <- unique(stats::na.omit(dat$artwork))
 
+  # Create glossar dictionary ##############################################
   if ("glossar" %in% artworks) {
+    cat("\n########## Creating glossar dictionary ##########", "\n")
     artworks <- artworks[artworks != "glossar"]
     glossar_files <- unique(subset(dat, dat$artwork == "glossar")$popup)
     glossar_dict <- create_glossardict(artworks, glossar_files, xmlpath = xmlpath)
@@ -82,16 +80,7 @@ create_eventlogs <- function(data, xmlfiles, xmlpath) {
   # Add trace for move events ##############################################
   cat("\n\n########## Adding trace variable for move events... ##########", "\n")
   dat4 <- add_trace_moves(dat3)
-
-  # Add topics: file names and topics ######################################
-  cat("\n########## Adding information about topics... ##########", "\n\n")
-  # remove artworks without XML information
-  #artworks <- artworks[!artworks %in% c("504", "505")]
-  # TODO: This is hardcoded! Remove it!
-  topics <- extract_topics(artworks, xmlfiles = xmlfiles, xmlpath = xmlpath)
-  
-  dat5 <- add_topic(dat4, topics = topics)
-  dat5
+  dat4
 }
 
 
diff --git a/R/extract_artworks.R b/R/extract_artworks.R
new file mode 100644
index 0000000..1500af8
--- /dev/null
+++ b/R/extract_artworks.R
@@ -0,0 +1,54 @@
+#' Creating data frame with information about artworks
+#'
+#' Information about artowrks are extracted from XML files and written to a
+#' data frame that contains `artist`, `title`, `misc`, and `description`.
+#'
+#' @param artworks A character vector with names of the artworks. Needs to
+#' correspond to the folder names which contain the XML files.
+#' @param xmlfiles Vector of names of index files, often something like
+#' `<artwork>.xml`. Need to be in the same order as artworks!
+#' @param xmlpath Path to folder where XML definitions of artworks live.
+#' @return Data frame.
+#' @export
+#' @examples
+#' # tbd
+extract_artworks <- function(artworks, xmlfiles, xmlpath) {
+  out <- NULL
+  i <- 1
+
+  for (artwork in artworks) {
+
+    if (length(xmlfiles) == 1) {
+      index_file <- xmlfiles
+    } else {
+      index_file <- xmlfiles[i]
+    }
+
+    index <- paste(xmlpath, artwork, index_file, sep = "/")
+    varnames <- c("artist", "title", "misc", "description")
+    xmllist <- XML::xmlToList(index)$header[varnames]
+
+    if (any(sapply(xmllist, is.null))) {# necessary for missing entries
+      names(xmllist) <- varnames
+      xmllist[which(sapply(xmllist, is.null))] <- NA
+    }
+    # remove German quotes
+    xmllist <- lapply(xmllist, function(x) gsub("\u201e|\u201c", "", x))
+    # remove HTML tags
+    xmllist <- lapply(xmllist, function(x) gsub("<br/>", " ", x))
+    xmldat <- as.data.frame(xmllist)
+    xmldat$artwork <- artwork
+    # trim white space from strings
+    xmldat$artist      <- trimws(xmldat$artist)
+    xmldat$title       <- trimws(xmldat$title)
+    xmldat$misc        <- trimws(xmldat$misc)
+    xmldat$description <- trimws(xmldat$description)
+    out <- rbind(out, xmldat)
+    i <- i + 1
+  }
+  out
+}
+
+# TODO: Check if artworks all artworks have a folder, catch it and throw
+# warning
+
diff --git a/R/extract_topics.R b/R/extract_topics.R
new file mode 100644
index 0000000..7056ebf
--- /dev/null
+++ b/R/extract_topics.R
@@ -0,0 +1,92 @@
+#' Creating data frame with artworks and topics
+#'
+#' Topics are extracted from XML files and written to a data frame that
+#' shows which artworks belong to which topics.
+#'
+#' @param artworks A character vector with names of the artworks. Needs to
+#' correspond to the folder names which contain the XML files.
+#' @param xmlfiles Vector of names of index files, often something like
+#' `<artwork>.xml`. Need to be in the same order as artworks!
+#' @param xmlpath Path to folder where XML definitions of artworks live.
+#' @return Data frame.
+#' @export
+#' @examples
+#' # tbd
+extract_topics <- function(artworks, xmlfiles, xmlpath) {
+
+  out <- NULL
+  i <- 1
+
+  for (artwork in artworks) {
+
+    index_file <- paste0(xmlpath, artwork, "/", xmlfiles[i])
+    suppressWarnings(
+      fnames <- gsub("^<card src=.*/(.*)./>$", "\\1",
+                           grep("^<card src=", trimws(readLines(index_file)),
+                                value = TRUE))
+    )
+
+    topic <- NULL
+    for (fname in fnames) {
+      suppressWarnings(
+        topic <- c(topic, gsub("^<card type=.(.*).>$", "\\1",
+          grep("^<card type=",
+            trimws(readLines(paste(xmlpath, artwork, fname, sep = "/"))),
+            value = T)))
+      )
+    }
+    out <- rbind(out, data.frame(artwork, file_name = fnames, topic))
+    i <- i + 1
+  }
+
+  out <- out[order(out$artwork), ]
+  rownames(out) <- NULL
+
+  out$index <- unlist(lapply(table(out$artwork), seq_len))
+  out
+}
+
+###########################################################################
+
+# Add topics: file names and topics
+
+add_topic <- function(data, topics) {
+
+  artworks <- unique(data$artwork)
+  tab_art <- lapply(artworks,
+               function(x) names(table(data$topicNumber[data$artwork == x])))
+  names(tab_art) <- artworks
+
+  tab_index <- lapply(tab_art, seq_along)
+
+  dat_split <- split(data, ~ artwork)
+
+  set_label <- function(x) {
+    artwork <- unique(x$artwork)
+    x$topicIndex <- factor(x$topicNumber, labels = tab_index[[artwork]])
+    x
+  }
+
+  dat_label <- lapply(dat_split, set_label)
+
+  set_topic <- function(x) {
+    artwork <- unique(x$artwork)
+    labels_file <- topics[topics$artwork == artwork,
+                          "file_name"][as.numeric(levels(x$topicIndex))]
+    x$topicFile <- as.character(factor(x$topicIndex, labels = labels_file))
+    labels_topic <- topics[topics$artwork == artwork,
+                          "topic"][as.numeric(levels(x$topicIndex))]
+    x$topic <- as.character(factor(x$topicIndex, labels = labels_topic))
+    x
+  }
+
+  dat_topic <- lapply(dat_label, set_topic)
+
+  #out <- do.call(rbind, dat_topic)
+  out <- dplyr::bind_rows(dat_topic)
+  out$topicIndex <- as.numeric(out$topicIndex)
+  out <- out[order(out$fileId, out$date.start, out$timeMs.start), ]
+  rownames(out) <- NULL
+  out
+}
+
diff --git a/R/helper.R b/R/helper.R
deleted file mode 100644
index 999dfff..0000000
--- a/R/helper.R
+++ /dev/null
@@ -1,214 +0,0 @@
-###########################################################################
-
-# Add case variable
-
-add_case <- function(data, cutoff = 20) {
-# TODO: What is the best choice for the cutoff here?
-
-  data$timediff <- as.numeric(diff(c(data$date.start[1], data$date.start)))
-  data$case <- NA
-  j <- 1
-  pb <- utils::txtProgressBar(min = 0, max = nrow(data), initial = NA, style = 3)
-
-  for (i in seq_len(nrow(data))) {
-    if (data$timediff[i] <= cutoff) {
-      data$case[i] <- j
-    } else {
-      j <- j + 1
-      data$case[i] <- j
-    }
-    utils::setTxtProgressBar(pb, i)
-  }
-  data$timediff <- NULL
-  data
-}
-
-###########################################################################
-
-# Add trace for moves
-
-add_trace_moves <- function(data) {
-
-  pbapply::pboptions(style = 3, char = "=")
-
-  trace_max <- max(data$trace, na.rm = TRUE)
-
-  #subdata_art <- split(data, ~ artwork)
-  subdata_case <- split(data, ~ case)
-
-  #subdata_list <- split(data, ~ artwork + case)
-  # --> does not work with complete data set
-  cat("Splitting data...", "\n")
-  subdata_list <- pbapply::pblapply(subdata_case, split, f = ~artwork)
-  subdata_list <- unlist(subdata_list, recursive = FALSE)
-
-  cat("Adding trace...", "\n")
-  subdata_trace <- pbapply::pblapply(subdata_list,
-        function(x) {
-          trace_max <<- trace_max + 1
-          add_trace_subdata(x, max_trace = trace_max)
-        }
-      )
-
-  out <- dplyr::bind_rows(subdata_trace)
-  out <- out[order(out$fileId, out$date.start, out$timeMs.start), ]
-  rownames(out) <- NULL
-
-  # Make trace a consecutive number
-  out$trace <- as.numeric(factor(out$trace, levels = unique(out$trace)))
-  out
-}
-
-
-add_trace_subdata <- function(subdata, max_trace) {
-
-  if (nrow(subdata) != 0) {
-
-    if (length(stats::na.omit(unique(subdata$trace))) == 1) {
-      subdata[subdata$event == "move", "trace"] <- stats::na.omit(unique(subdata$trace))
-    } else if (length(stats::na.omit(unique(subdata$trace))) > 1) {
-      for (i in 1:nrow(subdata)) {
-        if (subdata$event[i] == "move") {
-          if (i == 1) {
-            subdata$trace[i] <- stats::na.omit(unique(subdata$trace))[1]
-          } else {
-            subdata$trace[i] <- subdata$trace[i - 1]
-          }
-        }
-      }
-    } else if (all(is.na(subdata$trace))) {
-      for (i in 1:nrow(subdata)) {
-        subdata$trace[i] <- max_trace
-      }
-    }
-
-  } else {
-    warning("subdata has nrow = 0")
-  }
-  subdata
-}
-
-
-###########################################################################
-
-# Create data frame with file names and topics for each artwork
-
-extract_topics <- function(artworks, xmlfiles, xmlpath) {
-
-  out <- NULL
-  i <- 1
-
-  for (artwork in artworks) {
-
-    index_file <- paste0(xmlpath, artwork, "/", xmlfiles[i])
-    suppressWarnings(
-      fnames <- gsub("^<card src=.*/(.*)./>$", "\\1",
-                           grep("^<card src=", trimws(readLines(index_file)),
-                                value = TRUE))
-    )
-
-    topic <- NULL
-    for (fname in fnames) {
-      suppressWarnings(
-      topic <- c(topic, gsub("^<card type=.(.*).>$", "\\1",
-        grep("^<card type=",
-          trimws(readLines(paste(xmlpath, artwork, fname, sep = "/"))),
-          value = T)))
-      )
-    }
-    out <- rbind(out, data.frame(artwork, file_name = fnames, topic))
-    i <- i + 1
-  }
-
-  out <- out[order(out$artwork), ]
-  rownames(out) <- NULL
-
-  out$index <- unlist(lapply(table(out$artwork), seq_len))
-  out
-}
-
-###########################################################################
-
-# Add topics: file names and topics
-
-add_topic <- function(data, topics) {
-
-  artworks <- unique(data$artwork)
-  tab_art <- lapply(artworks,
-               function(x) names(table(data$topicNumber[data$artwork == x])))
-  names(tab_art) <- artworks
-
-  tab_index <- lapply(tab_art, seq_along)
-
-  dat_split <- split(data, ~ artwork)
-
-  set_label <- function(x) {
-    artwork <- unique(x$artwork)
-    x$topicIndex <- factor(x$topicNumber, labels = tab_index[[artwork]])
-    x
-  }
-
-  dat_label <- lapply(dat_split, set_label)
-
-  set_topic <- function(x) {
-    artwork <- unique(x$artwork)
-    labels_file <- topics[topics$artwork == artwork,
-                          "file_name"][as.numeric(levels(x$topicIndex))]
-    x$topicFile <- as.character(factor(x$topicIndex, labels = labels_file))
-    labels_topic <- topics[topics$artwork == artwork,
-                          "topic"][as.numeric(levels(x$topicIndex))]
-    x$topic <- as.character(factor(x$topicIndex, labels = labels_topic))
-    x
-  }
-
-  dat_topic <- lapply(dat_label, set_topic)
-
-  #out <- do.call(rbind, dat_topic)
-  out <- dplyr::bind_rows(dat_topic)
-  out$topicIndex <- as.numeric(out$topicIndex)
-  out <- out[order(out$fileId, out$date.start, out$timeMs.start), ]
-  rownames(out) <- NULL
-  out
-}
-
-###########################################################################
-
-# Create data frame with information on artworks
-
-extract_artworks <- function(artworks, files, xmlpath) {
-  out <- NULL
-  i <- 1
-
-  for (artwork in artworks) {
-
-    if (length(files) == 1) {
-      index_file <- files
-    } else {
-      index_file <- files[i]
-    }
-
-    index <- paste(xmlpath, artwork, index_file, sep = "/")
-    varnames <- c("artist", "title", "misc", "description")
-    xmllist <- XML::xmlToList(index)$header[varnames]
-
-    if (any(sapply(xmllist, is.null))) {# necessary for missing entries
-      names(xmllist) <- varnames
-      xmllist[which(sapply(xmllist, is.null))] <- NA
-    }
-    # remove German quotes
-    xmllist <- lapply(xmllist, function(x) gsub("\u201e|\u201c", "", x))
-    # remove HTML tags
-    xmllist <- lapply(xmllist, function(x) gsub("<br/>", " ", x))
-    xmldat <- as.data.frame(xmllist)
-    xmldat$artwork <- artwork
-    # trim white space from strings
-    xmldat$artist      <- trimws(xmldat$artist)
-    xmldat$title       <- trimws(xmldat$title)
-    xmldat$misc        <- trimws(xmldat$misc)
-    xmldat$description <- trimws(xmldat$description)
-    out <- rbind(out, xmldat)
-    i <- i + 1
-  }
-  out
-}
-