BackNext
2.3 AICC Communication Methods - HACP |
For web compatibility, two main communication models for results/settings were introduced: HACP (HTTP AICC Communication Protocol "Appendix A") and API (Application Programming Interface "Appendix B")
- HACP: HTTP AICC Communication Protocol - Described in Appendix A of the specification
- "Files" are packaged as a web page form result and are "posted" to the server
- The course can report results or can request information from the server
- Server responds with a "plain/text" message in the form of an AICC "file"
- Limitations to this implementation:
- AICC was initially designed for client server computing. The web paradigm is for dumb browsers and intelligent servers as apposed to the client server paradigm which is for intelligent client and intelligent server.
- This architecture is a problem for the web since browsers earlier than IE 5.5 cannot interpret this response, it can only display it as text. Browsers later than Microsoft IE 5.5 and Netscape 6.2 no longer have this limitation, but there are other security issues that affect the communication.
- To make Appendix A work with older browsers, either the browser needs to do all its communication through a Java applet, or there needs to be a relay device that converts the server response into a form that the browser can interpret (JavaScript).