begin-handler /start public
    @<h2>File Manager</h2>
    @To manage the uploaded files, <a href="<<print-path "/list">>">click here.</a><br/>
    @<br/>
    @<form action="<<print-path "/upload">>" method="POST" enctype="multipart/form-data">
    @    <label for="file_description">File description:</label><br>
    @    <textarea name="filedesc" rows="3" columns="50"></textarea><br/>
    @    <br/>
    @    <label for="filename">File:</label>
    @    <input type="file" name="file" value=""><br><br>
    @    <input type="submit" value="Submit">
    @</form>
 end-handler

 begin-handler /list public
     @<h2>List of files</h2>
     @To add a file, <a href="<<print-path "/start">>">click here</a><br/><br/>
     @<table border="1">
     @<tr>
     @    <td>File</td><td>Description</td><td>Size</td><td>Show</td><td>Delete</td>
     @</tr>
     run-query @db= \
         "select fileName, description, fileSize, fileID from files order by fileSize desc" \
         output file_name, description noencode, file_size, file_ID
         @<tr>
         @    <td><<print-out file_name web-encode>></td><td><<print-out description web-encode>><td><<print-out file_size web-encode>></td>
         @    <td><a href="<<print-path "/download">>/file_id=<<print-out file_ID url-encode>>">Show</a></td>
         @    <td><a href="<<print-path "/delete">>/action=confirm/file_id=<<print-out file_ID url-encode>>">Delete</a></td>
         @</tr>
     end-query
     @</table>
 end-handler

 begin-handler /upload public
    get-param filedesc      // file description from the upload form
    get-upload file local-file file_location size file_size \
        extension file_ext client-file file_filename
    @<h2>Uploading file</h2>
    run-query @db= \
         "insert into files (fileName, localPath, extension, description, fileSize) \
             values ('%s', '%s', '%s', '%s', '%s')" \
         input file_filename, file_location, file_ext, filedesc, $file_size
    end-query
    @File <<print-out file_filename web-encode>> of size <<print-out file_size >> \
         is stored on server at <<print-out file_location web-encode>>. \
         File description is <<print-out filedesc web-encode>>.<hr/>
 end-handler

 begin-handler /download public
     get-param file_id
     run-query @db= \
         "select localPath,extension from files where fileID='%s'" \
         input file_id \
         output local_path, ext \
         row-count num_files
             if-true ext equal ".jpg"
                 send-file local_path headers content-type "image/jpg"
             else-if ext equal ".png"
                 send-file local_path headers content-type "image/png"
             else-if ext equal ".pdf"
                 send-file local_path headers content-type "application/pdf"
             else-if
                 send-file local_path headers content-type "application/octet-stream" download
             end-if
     end-query
     if-true num_files not-equal 1
         @Cannot find this file!<hr/>
         exit-handler
     end-if
 end-handler

 begin-handler /delete public
    @<h2>Delete a file</h2>
    get-param action
    get-param file_id
    run-query @db="select fileName, localPath, description  from files where fileID='%s'" output file_name, local_path, desc input file_id
         if-true action equal "confirm" // get file information to confirm what will be deleted
            @Are you sure you want to delete file <<print-out file_name web-encode>> (<<print-out desc web-encode>>)? Click <a href="<<print-path "/delete">>?action=delete&amp;file_id=<<print-out file_id url-encode>>">Delete</a> or click the browser's Back button to go back.<br/>
         else-if action equal "delete"  // actual delete file, once confirmed
            begin-transaction @db
            run-query @db= "delete from files where fileID='%s'" input file_id error err no-loop
            if-true err not-equal "0"
                @Could not delete the file (error <<print-out err web-encode>>)
                rollback-transaction @db
            else-if
                delete-file local_path status st
                if-true st equal GG_OKAY
                    commit-transaction @db
                    @File deleted. Go back to <a href="<<print-path "/start">>">start page</a>
                else-if
                    rollback-transaction @db
                    @File could not be deleted, error <<print-out st>>
                end-if
            end-if
         else-if
            @Unrecognized action <<print-out action web-encode>>
         end-if
    end-query
 end-handler