for our dashboard I want to add an additional textarea that allows for further
configuration of the Dashboard. We have Moodle 3.3.
In order to achieve that I added something like:
settings->add( new admin_setting_configtextarea( ...
in the settings.php which of course works fine. Now I want validate what frontend users
fill in in my new settings field. The user is required to fill in a
JSON String. So I want to check wether the JSON -String is well formed and
make ,if possible, checks, if the entries are plausible.
How can I achieve this ? do I need admin_external_setup instead of admin_setting_configtextarea ?
I want to give the frontend user suitable (error-)messages.
What is basically here the way ? how/ where to validate ? When does JS comes into play?
Any Info, How tos etc would be nice.