Matthew R. Wilson
5f2d7355e4
New ShowScreenOpts() function, which takes a new ScreenOpts struct, to control various aspects of the ShowScreen behavior. This should now be used in favor of the deprecated ShowScreen() and ShowScreenNoResponse() functions, and allows for the additional of future options without needing to continue making new functions or breaking the public API.
2.1 KiB
Go 3270 Server Library
This library allows you to write Go servers for tn3270 clients by building 3270 data streams from fields and processing the client's response to receive the attention keys and field values entered by users.
The library is incomplete, likely buggy, and under heavy development: the interface is UNSTABLE until this notice is removed from this readme and version 1.0 is released.
Everything I know about 3270 data streams I learned from Tommy Sprinkle's tutorial. The tn3270 telnet negotiation is gleaned from RFC 1576: TN3270 Current Practices, RFC 1041: Telnet 3270 Regime Option, and RFC 854: Telnet Protocol Specification. The IANA maintains a useful reference of telnet option numbers.
Usage
See the example folders for a quick demonstration of using the library. example1 uses the lower-level function ShowScreen(), and example2 uses a higher-level function HandleScreen(). example3 demonstrates updating the client's 3270 display while waiting for a response by using an update thread and a waiting response thread.
Here's a video introducing the library as well.
Future Enhancements
I would like to add:
Extended field attribute support (e.g. color).Done- Utility functions for easily laying out forms.
Known Problems
- The telnet negotiation does not check for any errors or for any responses from the client. We just assume it goes well and we're actually talking to a tn3270 client.
License
This library is licensed under the MIT license; see the file LICENSE for details.