onclick and onevent now support callback functions; fixes #92

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: shinyjs
 Title: Easily Improve the User Experience of Your Shiny Apps in Seconds
-Version: 0.7.9005
+Version: 0.7.9006
 Authors@R: person("Dean", "Attali", email = "[email protected]",
     role = c("aut", "cre"))
 Description: Perform common useful JavaScript operations in Shiny apps that will

NEWS.md

@@ -1,7 +1,8 @@
 # shinyjs 0.7.xxxx
 
+- `onclick` and `onevent` now support callback functions, and the JavaScript Event object is passed to the callback (#92)
 - added `runcodeUI()` and `runcodeServer()` functions that you can add to your app in order to run arbitrary R code interactively
-- added `showLog()` function which lets you redirect all JavaScript logging statements to the R console, to make it easier and quicker to debug apps without having to open the JS console
+- added `showLog()` function which lets you redirect all JavaScript logging statements to the R console, to make it easier and quicker to debug apps without having to open the JS console (#88)
 - added `alert()` as an alias for `info()`
 
 # shinyjs 0.7

R/onevent.R

@@ -9,7 +9,10 @@
 #' @param event The event that needs to be triggered to run the code. See below
 #' for a list of possible event types.
 #' @param id The id of the element/Shiny tag
-#' @param expr The R expression to run after the event is triggered
+#' @param expr The R expression or function to run after the event is triggered.
+#' If a function with an argument is provided, it will be called with the
+#' JavaScript Event details as its argument. Using a function can be useful
+#' when you want to know for example what key was pressed on a "keypress" event.
 #' @param add If \code{TRUE}, then add \code{expr} to be executed after any
 #' other code that was previously set using \code{onevent} or \code{onclick}; otherwise
 #' \code{expr} will overwrite any previous expressions. Note that this parameter
@@ -33,11 +36,13 @@
 #'     ui = fluidPage(
 #'       useShinyjs(),  # Set up shinyjs
 #'       p(id = "date", "Click me to see the date"),
+#'       p(id = "coords", "Click me to see the mouse coordinates"),
 #'       p(id = "disappear", "Move your mouse here to make the text below disappear"),
 #'       p(id = "text", "Hello")
 #'     ),
 #'     server = function(input, output) {
 #'       onclick("date", alert(date()))
+#'       onclick("coords", function(event) { alert(event) })
 #'       onevent("mouseenter", "disappear", hide("text"))
 #'       onevent("mouseleave", "disappear", show("text"))
 #'     }
@@ -94,7 +99,22 @@ oneventHelper <- function(event, id, expr, add) {
   # every time the given event occurs
   expr <- deparse(expr)
   shiny::observeEvent(session$input[[shinyInputId]], {
-    eval(parse(text = expr), envir = parentFrame)
+    ret <- eval(parse(text = expr), envir = parentFrame)
+
+    # If a callback function was provided, call it with the event as argument
+    if (is.function(ret)) {
+      if (length(formals(ret)) == 0) {
+        ret()
+      } else {
+        event <- session$input[[shinyInputId]]
+        event[['shinyjsRandom']] <- NULL
+        ret(event)
+      }
+    }
+    # If an expression was provided, evaluate it
+    else {
+      ret
+    }
   })
 
   invisible(NULL)

inst/srcjs/shinyjs-default-funcs.js

@@ -1,4 +1,4 @@
-// shinyjs 0.7.9005 by Dean Attali
+// shinyjs 0.7.9006 by Dean Attali
 // Perform common JavaScript operations in Shiny apps using plain R code
 
 shinyjs = function() {
@@ -432,19 +432,32 @@ shinyjs = function() {
     var attrName = "data-shinyjs-" + params.event;
 
     // if this is the first event handler of this event type we attach to this
-    // element, initialize the data attribute and add the  event handler
+    // element, initialize the data attribute and add the event handler
     var first = !(el[0].hasAttribute(attrName));
     if (first) {
       el.attr(attrName, JSON.stringify(Object()));
 
-      el[params.event](function() {
+      el[params.event](function(event) {
+        // Store a subset of the event properties (many are non-serializeable)
+        var props = ['altKey', 'button', 'buttons', 'clientX', 'clienty',
+          'ctrlKey', 'pageX', 'pageY', 'screenX', 'screenY', 'shiftKey',
+          'which', 'charCode', 'key', 'keyCode'];
+        var eventSimple = {};
+        $.each(props, function(idx, prop) {
+          if (prop in event) {
+            eventSimple[[prop]] = event[[prop]];
+          }
+        });
+        eventSimple.shinyjsRandom = Math.random();
+
         var oldValues = JSON.parse(el.attr(attrName));
         var newValues = Object();
         $.each(oldValues, function(key, value) {
           var newValue = value + 1;
           newValues[key] = newValue;
-          Shiny.onInputChange(key, newValue);
+          Shiny.onInputChange(key, eventSimple);
         });
+
         el.attr(attrName, JSON.stringify(newValues));
       });
     }