code: protected CmsUUID switchToTempProject() throws CmsException {
  
          // store the current project id in member variable
          m_currentProjectId = getSettings().getProject();
          CmsUUID tempProjectId = OpenCms.getWorkplaceManager().getTempFileProjectId();
          getCms().getRequestContext().setCurrentProject(getCms().readProject(tempProjectId));
          return tempProjectId;
      }
docs: Helper method to change the current project to the temporary file project.<p>
  
  The id of the old project is stored in a member variable to switch back.<p>
  
  @return the id of the tempfileproject
  @throws CmsException if getting the tempfileproject id fails