Modifying a teal Application With R Options
NEST CoreDev
Source:vignettes/teal-options.Rmd
teal-options.RmdMotivation
Some R packages use options to modify their
runtime behavior. They usually specify sensible default values for
internal function arguments or determine responses to users actions. For
example, testthat uses an option
testthat.progress.max_fails to define a default number of
failed expectations before the testing functions terminate execution.
While some of these adjustable values can be exposed as function
parameters, some are confined to an option. This vignette details the
options available in the package teal and it’s supporting
packages teal.logger, teal.widgets, and
teal.slice.
Setting an option
At any time during an interactive session, you can change an option using:
options(option_to_set = "value")A way to change options for only the execution of a specific block of
code is with the withr package like so:
withr::with_options(list(digits = 3), print(pi))## [1] 3.14After the line above is run the option, digits, will go
back to its value before the line was run.
The function getOption allows to inspect the value of an
option:
getOption("option_to_set")## [1] "value"Once set, the value of an option persists during a session, but it
returns to the default value in a new session. Make sure to change the
options after all the teal-related packages are loaded
because some of them initialize the options themselves and will
overwrite your custom values.
Options used in a teal application
teal.bs_theme (bslib::bs_theme
object)
This option controls the bootstrap theme and version used in
teal apps. Achieve better UX with the customized UI of an
app. Please see the vignette on
Bootstrap themes to read more about the functionality.
Default: NULL
teal.load_nest_code (character)
The value of this option is appended to the top of the code rendered
when using the Show R Code modal button.
Default:
"# Add any code to install/load your NEST environment here".
teal.threshold_slider_vs_checkboxgroup
(numeric)
This is the threshold that determines if a variable is treated as a
factor in the filter panel. If the number of unique values of a variable
is less than this threshold the variable will be treated as a factor
instead of its original class. As an example, imagine
teal.threshold_slider_vs_checkboxgroup equals to 2. Then a
numeric variable c(1, 1, 1), which has only one unique
value, is treated as a factor in the filter panel (and in the filter
panel only!). The filter panel creates a checkbox widget to filter
values from this variable, as it would for a factor variable, instead of
the usual numeric range selector.
Default: 5.
teal.basic_table_args (basic_table_args
object)
This specifies the list of arguments passed to every call to
rtables::basic_table made in a teal
application. This can be used to format rtables without
making any changes to the application code. See the documentation of
teal.widgets::basic_table_args for more information.
Default: teal.widgets::basic_table_args().
teal.ggplot2_args (ggplot2_args
object)
This option allows modifying labels and themes of all
ggplot2 plots in a teal application. See the
documentation of teal.widgets::ggplot2_args for more
information.
Default: teal.widgets::ggplot2_args().
teal.plot_dpi (integer value 24 or larger)
This option controls the dots per inch of the graphs rendered and
downloaded when using the module plot_with_settings from
the teal.widgets package.
Default: 72
teal.log_layout (character)
This defines the layout of a log message used in a teal
application. teal uses this layout to format the emitted
log messages. Read the documentation of
teal.logger::register_logger for more information.
Default:
"[{level}] {format(time, \"%Y-%m-%d %H:%M:%OS4\")} pid:{pid} token:[{token}] {ans} {msg}".
Note that this layout is formatted by the glue
package.
teal.log_level (character)
This is the logging level threshold used in a teal
application. A teal application will not emit logs below
this level. Read the documentation of
teal.logger::register_logger for more information. Possible
values: "TRACE", "INFO",
"WARNING", "ERROR". See the documentation of
logger::TRACE for all possible values of logging threshold
and more information on what it does.
Default: "INFO".
Note that there are two levels considered less severe than
"INFO": "DEBUG" and "TRACE". In
order to see the log messages for these two levels as well, change the
log level from the default to "TRACE", the least severe log
level.