Introduce clean_media function in class openxml_document and use it i…

…n remove_slide function

R/openxml_document.R

@@ -54,8 +54,30 @@ openxml_document <- R6Class(
     },
     relationship = function(){
       private$rels_doc
-    }
+    },
+    clean_media = function() {
+      # get package directory
+      package_dir <- dirname(dirname(dirname(private$rels_filename)))
+      # find .xml.rels files
+      rel_files <- list.files(package_dir, pattern = "\\.xml.rels$", recursive = TRUE, full.names = TRUE)
+
+      # collect media files that are referenced in .xml.rels files
+      media_file_rels <- lapply(rel_files, function(xml){
+        zz <- xml2::read_xml(xml)
+        rels <- xml2::xml_children(zz)
+        targets <- xml2::xml_attr(rels, "Target")
+        grep("^\\.\\./media/", targets, value = TRUE)
+      })
+      media_file_rels <- file.path(dirname(dirname(private$rels_filename)), sub("\\.\\./", "", unique(unlist(media_file_rels))))
 
+      # get files in media folder
+      media_folder <- grep("/media$", list.dirs(package_dir), value = TRUE)
+      media_files <- list.files(media_folder, recursive = TRUE, full.names = TRUE)
+
+      # delete unused files
+      files_to_delete <- media_files[!(media_files %in% media_file_rels)]
+      unlink(files_to_delete, force = TRUE)
+    }
   ),
   private = list(
 

R/ppt_classes.R

@@ -79,6 +79,7 @@ presentation <- R6Class(
       private$slide_rid <- private$slide_rid[-dropid]
 
       private$update_xml()
+      self$clean_media()
 
       self
     }