Strings passing between Caproto and pyepics GUI

[vstadnytskyi]

Code:
server_string_pv.py has 3 pvs. Str_in is a write PV that can be changed by clients. The str_out PV is all caps of the str_in. The N_chr PV shows how many characters in the string.
server_string_pv_gui.py pyepics gui

str_in = pvproperty(value='', dtype = str, max_length = 1000)
str_out = pvproperty(value='', dtype = str, read_only = True)
N_chr = pvproperty(value=3, read_only = True)

Problems:
caproto server truncates all input PV written into str_in if the input string exceeds the max_length. The str_out which is read-only doesn't suffer the same. I guess because if originates from the server itself.

pyepics problems:
The PVTextCtrl field accepts the value in the field after dirty_timeout, return key or if focus is moved away. If I selected the GUI window the last known field will be selected. Now, if I move away without making any changes the server will get PV associated with that field.