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Navigating Past a Blank Screen that Requires Input
Technical Note 10003
Last Reviewed 11-Sep-2008
Applies To
Verastream Host Integrator version 6.5 or earlier
Summary
Technical Note 10003
Last Reviewed 11-Sep-2008
Applies To
Verastream Host Integrator version 6.5 or earlier
Summary
When navigating a host application using Verastream Host Integrator Design Tool, if you encounter a blank screen that requires input to proceed, We highly recommend that you do NOT define the blank screen as an entity; rather, use the TransmitToLocation, WriteVarToTerminal (or similar commands such as TransmitToTerminal or WriteVarToLocation), depending on your specific needs. This technical note explains how to use the TransmitToLocation and WriteVarToTerminal commands to navigate though blank screens.
Note: This information applies to version 6.5 and earlier. Beginning in version 6.6, modeling of a blank entity is acceptable due to keyboard lock synchronization improvements. If you are upgrading to version 6.6 from an earlier version, see the Keyboard Lock Compatibility setting in Technical Note 40023.
Navigating Through Blank Screens
If the host application you are working with requires you to enter input into a blank screen, it is best to avoid defining the blank screen as an entity. Normal clearing of the host screen, under certain timing conditions, may result in identification of the blank entity (or attributes on a blank entity), causing sporadic entity exceptions.
In this situation, we recommend that (if your host permits it) you use operations to navigate through the blank screen; thus, avoiding the need to define the screen as an entity. To navigate through the blank screen, use the TransmitToLocation, WriteVarToTerminal, or similar commands.
Using TransmitToLocation
If you need to transmit a specific string to the blank screen, use the TransmitToLocation operation to enter the required string.
In the example presented in Figure 1, the first three commands apply to the screen that precedes the blank screen; the last two commands apply to the blank screen. TransmitToLocation is used to transmit the string 'acct', followed by a carriage return (TransmitTerminalKey rcIBMEnterKey).
Figure 1: TransmitToLocation
If you are creating a 3270 model that uses a "TransmitTerminalKey rcIBMClearKey" command to get the blank screen, before the transmitting command, ensure the keyboard is enabled ("WaitForKeyboardEnabled 0"). This will avoid timeouts due to loss of synchronization.
Using WriteVarToTerminal
If you need to transmit a variable to the blank screen, based on user input in the front end application, use the WriteVarToTerminal operation combined with a defined variable.
In the example presented in Figure 2, the input is the value of the AcctNumber variable (the account number entered in the front end application). The first four commands apply to the screen that precedes the blank screen; the last two commands apply to the blank screen. In this instance, WriteVarToTerminal is used to transmit the content of the AcctNumber variable (which is currently 'AR24558', as seen in Figure 3), followed by a carriage return (TransmitTerminalKey rcVtReturnKey).
Figure 2: WriteVarToTerminal
The variable, AcctNumber, used in this example is defined in Verastream Design Tool under Model > Variables. This variable is set by the font-end code at runtime and contains the account number entered by the end user. When the final procedure is run, the operation will use the current value of this variable.
Figure 3: Variable
