module_validate_error: Execute and validate `teal_data_module`

Description

This is a low level module to handle teal_data_module execution and validation. teal_transform_module() inherits from teal_data_module() so it is handled by this module too. srv_teal() accepts various data objects and eventually they are all transformed to reactive teal.data::teal_data() which is a standard data class in whole teal framework.

Usage

ui_validate_error(id)
srv_validate_error(id, data, validate_shiny_silent_error)
ui_check_class_teal_data(id)
srv_check_class_teal_data(id, data)
ui_check_module_datanames(id)
srv_check_module_datanames(id, data, modules)

Value

reactive

teal_data

Arguments

id: (character(1)) shiny module instance id.
data: (teal_data, teal_data_module, or reactive returning teal_data) The data which application will depend on.
validate_shiny_silent_error: (logical) If TRUE, then shiny.silent.error is validated and
modules: (teal_modules or teal_module) For datanames validation purpose

data validation

Executed teal_data_module() is validated and output is validated for consistency. Output data is invalid if:

teal_data_module() is invalid if server doesn't return reactive. Immediately crashes an app!
reactive throws a shiny.error - happens when module creating teal.data::teal_data() fails.
reactive returns qenv.error - happens when teal.data::teal_data() evaluates a failing code.
reactive object doesn't return teal.data::teal_data().
teal.data::teal_data() object lacks any datanames specified in the modules argument.

teal (observers in srv_teal) always waits to render an app until reactive teal_data is returned. If error 2-4 occurs, relevant error message is displayed to the app user. Once the issue is resolved, the app will continue to run. teal guarantees that errors in data don't crash the app (except error 1).