Code Utilities
The MDI apps framework has a series of utility functions that are always available to any app, unless overwritten by a declaration in your app code, which is always sourced last when an app is loaded.
MDI utility functions are too numerous to document individually, but if you find that base R lacks some obvious function, consider perusing the scripts identified below to see if it exists there.
The utility folder scripts are organized by overall purpose with descriptive names, such as strings.R and stats.R, and each script contains typically multiple support functions. Read the comments and code for usage information.
Global utilities
The following framework folder:
has a series of R scripts that are sourced whenever an app is loaded. Importantly, they are sourced outside the scope of a specific user session, so do not have access to session variables, such as input or session, unless they are passed as arguments to the function.
Thus, these scripts are where you will find generic utilities such as commify() - to format numbers with commas - fitTrendline() - a wrapper around various curve-fitting functions - etc.
Session utilities
The following framework folder:
has a series of R scripts that are also sourced whenever an app is loaded, however, these are sourced within the scope of a specific user session and have access to all session variables without passing them as arguments.
Please note that many scripts in the session utilities folder are used internally by the framework to construct appStep pages and similar, and are less likely to have simple utility functions - see the global utilities, above. However, advanced developers may find it necessary to call these functions when writing complex pages.
Module utilities
In addition to global and session utilities provided by and for the framework overall, many modules have their own utilities scripts, named <moduleName>_utilities.R by default. Please check a module’s folder for details.
Many module-level utilities are described in these documentation pages for modules that are part of the MDI framework.
Developer code monitoring tools
A final set of utilities help developers monitor code for development and debugging purposes. Many are found here:
That script is only sourced in developer mode and its functions must not be used in production apps.
External utility libraries
If you have a utilities library you particularly like, remember that you can always require an R data package for your tool suite or app. You are not required to use the MDI’s utility functions.