utility for server/ui to check value of a global default setting or user-defined setting

Usage

global_or_param(vname)

Arguments

vname: a global default or user param - do a global find in files of source code for this function to see how / where it is used.

Value

value of the param, or NULL if not found

Details

This and golem::get_golem_options() are very similar tools, useful in server and ui. See help for get_global_defaults_or_user_options()

global_or_param() is used a lot in server and also ui (while sometimes golem::get_golem_options() had been used instead but now is not, for the same purpose). It is used generally in ui to set default values for params that are set in the global_defaults_ files and often can be modified in the advanced tab. To provide alternative values as params passed to ejamapp() you would have to understand the options by seeing what they are defaulted to in the files and how they are used as parameters in ui or server. See ejamapp()

This is much like golem::get_golem_options() but global_or_param() is more flexible/robust since it will, if vname is not already defined as found by golem::get_golem_options()

then as second best, see if it was defined in global_defaults_package and just not yet stored as golem options because the shiny app has not yet launched. That lets any function or vignette find the values defined in global_defaults_package.R even if a shiny app has not yet launched.

Then as a last resort, check if the param called vname is defined in the search path such as in the calling or global envt already somehow, and return that value if it exists. But if it is not in golem options and not found in search path, this returns NULL