def post(self):
        '''This handles POST requests.

        Saves the changes made by the user on the frontend back to the current
        checkplot-list.json file.

        '''

        # if self.readonly is set, then don't accept any changes
        # return immediately with a 400
        if self.readonly:

            msg = "checkplotserver is in readonly mode. no updates allowed."
            resultdict = {'status':'error',
                          'message':msg,
                          'readonly':self.readonly,
                          'result':None}

            self.write(resultdict)
            raise tornado.web.Finish()


        objectid = self.get_argument('objectid', None)
        changes = self.get_argument('changes',None)

        # if either of the above is invalid, return nothing
        if not objectid or not changes:

            msg = ("could not parse changes to the checkplot filelist "
                   "from the frontend")
            LOGGER.error(msg)
            resultdict = {'status':'error',
                          'message':msg,
                          'readonly':self.readonly,
                          'result':None}

            self.write(resultdict)
            raise tornado.web.Finish()


        # otherwise, update the checkplot list JSON
        objectid = xhtml_escape(objectid)
        changes = json.loads(changes)

        # update the dictionary
        if 'reviewed' not in self.currentproject:
            self.currentproject['reviewed'] = {}

        self.currentproject['reviewed'][objectid] = changes

        # update the JSON file
        with open(self.cplistfile,'w') as outfd:
            json.dump(self.currentproject, outfd)

        # return status
        msg = ("wrote all changes to the checkplot filelist "
               "from the frontend for object: %s" % objectid)
        LOGGER.info(msg)
        resultdict = {'status':'success',
                      'message':msg,
                      'readonly':self.readonly,
                      'result':{'objectid':objectid,
                                'changes':changes}}

        self.write(resultdict)
        self.finish()
This handles POST requests.

        Saves the changes made by the user on the frontend back to the current
        checkplot-list.json file.