App development on the Prime

[CheshireChris]

More interesting discoveries today. I've worked out how to use the INPUT command to display a complex input form with multiple fields of different data types (numbers, choice fields, and checkboxes). This is straightforward in principle, but in practice you end up with an immensely long command with multiply-nested lists as parameters, and it's really easy to get confused as to what's what. If you get something wrong you either get a cryptic "Syntax Error" if the code is wrong, or the input form simply doesn't appear if the code is syntactically correct but logically wrong, for example if the number of help prompts that doesn't match the number of input fields. I'll probably find it easier next time. An interactive visual input form builder such as the one in Microsoft Visual Studio for Windows would be an extremely useful tool. Something I might consider for the future! This took most of my evening to get working, but I'm pleased that I persevered.

Another useful thing I discovered: I was wondering why the text I entered on my app's "Info" page (displayed by pressing SHIFT+APP) kept vanishing. I eventually realised that you have to use the "ANote" command to store it permanently. This writes it to a file called "appname.hpappnote" in the app directory and once there it no longer vanishes .

Finally, my Prime was frequently hanging up and requiring a reboot if I either shutdown my laptop with the Prime connected to the USB port, or simply disconnected the USB cable with the HP Connectivity Kit program running. I've now discovered that the "safe" way to disconnect is to close the HCK app on the PC and then disconnect the USB cable before shutting down the laptop. The Prime is happy with that.

Another useful few hours of exploration! Hope I'm not boring people with these ramblings...