553 introduce internal log_shiny_input_changes function

DESCRIPTION

@@ -23,6 +23,7 @@ Imports:
     logger (>= 0.2.0),
     methods,
     shiny (>= 1.6.0),
+    utils,
     withr (>= 2.1.0)
 Suggests:
     knitr (>= 1.42),

NAMESPACE

@@ -1,5 +1,6 @@
 # Generated by roxygen2: do not edit by hand
 
+export(log_shiny_input_changes)
 export(log_system_info)
 export(register_handlers)
 export(register_logger)

NEWS.md

@@ -1,5 +1,8 @@
 # teal.logger 0.2.0.9003
 
+* New function `log_shiny_input_changes` based on `logger` implementation, but curated to `teal` needs. 
+It allows to track all shiny inputs changes in teal modules on `TRACE` level with appended namespace name.
+
 # teal.logger 0.2.0
 
 * New function `register_handlers` to register global handlers for logging messages, warnings and errors.

R/log_shiny_input_changes.R

@@ -0,0 +1,71 @@
+#' Auto logging input changes in Shiny app
+#'
+#' This is to be called in the \code{server} section of the Shiny app.
+#'
+#' Function having very similar behavior as [logger::log_shiny_input_changes()] but adjusted for `teal` needs.
+#'
+#' @param input passed from Shiny \code{server}
+#' @param excluded_inputs character vector of input names to exclude from logging
+#' @param excluded_patterns character of length one including a grep pattern of names to be excluded from logging
+#' @param namespace the name of the namespace
+#' @examples
+#' \dontrun{
+#' library(shiny)
+#'
+#' ui <- bootstrapPage(
+#'   numericInput("mean1", "mean1", 0),
+#'   numericInput("mean2", "mean2", 0),
+#'   numericInput("sd", "sd", 1),
+#'   textInput("title", "title", "title"),
+#'   textInput("foo", "This is not used at all, still gets logged", "foo"),
+#'   passwordInput("password", "Password not to be logged", "secret"),
+#'   plotOutput("plot")
+#' )
+#'
+#' server <- function(input, output) {
+#'   log_shiny_input_changes(input, excluded_inputs = "password", exclude_patterns = "mean")
+#'
+#'   output$plot <- renderPlot({
+#'     hist(rnorm(1e3, input$mean, input$sd), main = input$title)
+#'   })
+#' }
+#'
+#' shinyApp(ui = ui, server = server)
+#' }
+#' @export
+log_shiny_input_changes <- function(
+    input,
+    namespace = NA_character_,
+    excluded_inputs = character(),
+    excluded_patterns = "_width$") {
+  session <- shiny::getDefaultReactiveDomain()
+  if (!(shiny::isRunning() || inherits(session, "MockShinySession"))) {
+    stop("No Shiny app running, it makes no sense to call this function outside of a Shiny app")
+  }
+  ns <- ifelse(!is.null(session), session$ns(character(0)), "")
+
+  # utils::assignInMyNamespace and utils::assignInNamespace are needed
+  # so that observer is executed only once, not twice.
+  input_values <- shiny::isolate(shiny::reactiveValuesToList(input))
+  utils::assignInMyNamespace("shiny_input_values", input_values)
+
+  shiny::observe({
+    old_input_values <- shiny_input_values
+    new_input_values <- shiny::reactiveValuesToList(input)
+    names <- unique(c(names(old_input_values), names(new_input_values)))
+    names <- setdiff(names, excluded_inputs)
+    if (length(excluded_patterns)) {
+      names <- grep(excluded_patterns, names, invert = TRUE, value = TRUE)
+    }
+    for (name in names) {
+      old <- old_input_values[name]
+      new <- new_input_values[name]
+      if (!identical(old, new)) {
+        message <- trimws("{ns} Shiny input change detected in {name}: {old} -> {new}")
+        logger::log_trace(message, namespace = namespace)
+      }
+    }
+    utils::assignInNamespace("shiny_input_values", new_input_values, ns = "teal.logger")
+  })
+}
+shiny_input_values <- NULL

_pkgdown.yml

@@ -28,3 +28,4 @@ reference:
       - register_logger
       - register_handlers
       - suppress_logs
+      - log_shiny_input_changes