How You Can Create Non-interactive Applications
Because ghost frames and 4GL procedures do not require the window manager to be running, you can write OpenROAD applications that run entirely without user interaction. To execute these applications without running the window manager, use the
-nowindows flag (see
Command Line Method to Run an Application from an Image) when invoking the RunImage utility.
When you run an OpenROAD application without the window manager, information that would ordinarily display as a pop-up frame on the executing window is redirected to the Trace window and the w4gl.log file.
This redirection of information includes the following items:
• Informational pop-up messages provided by OpenROAD such as those containing error messages
• 4GL statements that do not require user response such as the message statement and the InfoPopup method
• 4GL statements that require user response such as the prompt statement and the ReplyPopup method
Note: Because statements that require user response block the application until answered, you should not include such statements in frames or procedures that are to be run non-interactively. Moreover, because end users may not notice informational statements directed to the error log file or Trace window, you also may want to avoid informational statements that require user response.
Other coding restrictions for running applications without the window manager include attempting to call, open, or go to frames that contain forms. These actions result in error messages.
For more information about running applications and the RunImage utility, see
Managing and Deploying Applications.