Progress
Open Client
Developer’s Guide
Remote 4GL Methods
ProxyGen maps each 4GL procedure (internal or external) and user-defined function that you expose on the AppServer to a Remote 4GL method. When invoked, each Remote 4GL method executes the procedure (or user-defined function) on the AppServer, passes any parameter values, and makes any return values available to the Open Client.
NOTE: If the 4GL procedure has a super procedure, the proxy also contains Remote 4GL methods for the super procedure as long as the remote procedure declares the super procedure prototypes. For more information, see the information on programming for Open Client applications in Building Distributed Applications Using the Progress AppServer .The following sections provide information about:
Identifying the Generated Methods
ProxyGen generates method names using automatic conversions and conventions. For more information, see Generating and Managing Proxies." In addition, you can customize the method names in ProxyGen. Thus, each method name might not exactly match the name of the corresponding 4GL procedure or function. Use the generated Java source files for Java clients and the Type Library for ActiveX clients as a reference for method names in your proxy.
Passing Parameters
ProxyGen maps 4GL data types to equivalent data types in the Open Client for 4GL INPUT, OUTPUT, and INPUT-OUTPUT parameters.
For more information on data type mapping for your type of Open Client, see for:
- Java Open Clients — "Programming Java Clients"
- ActiveX Open Clients — "Programming ActiveX Controller Clients"
Handling Return Values
For any remote 4GL procedure, the corresponding proxy method always returns
void
. After calling this method, the client can access the current value of the 4GL RETURN-VALUE function by calling the following common methods for each type of Open Client:These methods return the current value of RETURN-VALUE as set by the RETURN statement most recently executed on this connection. AppObjects, SubAppObjects, and ProcObjects all support this method.
NOTE: The RETURN-VALUE function is set in the 4GL using the RETURN string or the RETURN ERRORstring
statement. For more information on these statements, see the Progress Language Reference , and for how they function in an AppServer application, see Building Distributed Applications Using the Progress AppServer .For any remote user-defined function, ProxyGen defines the corresponding method to return a value that is compatible with the 4GL data type returned by the user-defined function.
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