When you select HTML-based property page handler in the MetaBase configuration, proppage.dll unit will display user-defined HTML document instead of 3 hard-coded data file description tabs. Following list of methods and properties are available through window.external object:
HTML application should obtain file name using following methods: window.external.Server property (active data window in DM2003 object model), window.external.FileName property (Server=null when invoked by file managers), or document.location.search (for dynamically created HTML, when metadata stored on the server). When user change metadata (fields in the HTML), the page should call window.external.EnableApply method to notify property page that "Apply" button must be enabled. When user clicks "OK" or "Apply" buttons on the property page, Server_OnApply event fired. If property page is shown by DM2003, the HTML document should use window.external.Server.ExpSettings property to obtain experiment facility configuration. Methods ReadFile and WriteFile may be used to obtain access to the file system (files with metadata).
Warning: at present this feature was not completely implemented since it was discovered that instantiation of ActiveX components from property pages handler results in the crash of file manager application (this trouble doesn't affect DM2003.EXE). Another problem related to the well-known ENTER key bug in WebBrowser control.