Crosstalk works with DT::datatable

Doesn't work with filter_checkbox.

NAMESPACE

@@ -3,4 +3,5 @@
 export(renderSummarywidget)
 export(summarywidget)
 export(summarywidgetOutput)
+import(crosstalk)
 import(htmlwidgets)

R/summarywidget.R

@@ -45,6 +45,7 @@ summarywidget <- function(data,
         stop("Unexpected two-sided formula: ", deparse(selection))
       selection = eval(selection[[2]], data, environment(selection))
     }
+
     if (!is.logical(selection))
       stop("Selection must contain TRUE/FALSE values.")
     data = data[selection,]

inst/htmlwidgets/summarywidget.js

@@ -1,20 +1,19 @@
 HTMLWidgets.widget({
-
   name: 'summarywidget',
-
   type: 'output',
 
   factory: function(el, width, height) {
 
-    filterKeys = function(obj, keys) {
+    var filterKeys = function(obj, keys) {
       var result = {};
       keys.forEach(function(k) { result[k]=obj[k];});
+      return result;
     };
 
     return {
       renderValue: function(x) {
 
-        // Make a data object with keys
+        // Make a data object with keys so we can easily update the selection
         var data = {};
         var i;
         if (x.settings.crosstalk_key === null) {
@@ -27,30 +26,32 @@ HTMLWidgets.widget({
           }
         }
 
-        update = function(d) {
+        // Update the display to show the values in d
+        var update = function(d) {
           // Get a simple vector. Don't use Object.values(), RStudio doesn't seem to support it.
           var values = [];
           for (var key in d) {
             if (d.hasOwnProperty(key)) { values.push(d[key]);}
           }
 
-        var value = 0;
-        switch (x.settings.statistic) {
-          case 'count':
-            value = values.length;
-            break;
-          case 'sum':
-            value = values.reduce(function(acc, val) {return acc + val;}, 0);
-            break;
-          case 'mean':
-            value = values.reduce(function(acc, val) {return acc + val;}, 0) / values.length;
-            break;
-        }
+          var value = 0;
+          switch (x.settings.statistic) {
+            case 'count':
+              value = values.length;
+              break;
+            case 'sum':
+              value = values.reduce(function(acc, val) {return acc + val;}, 0);
+              break;
+            case 'mean':
+              value = values.reduce(function(acc, val) {return acc + val;}, 0) / values.length;
+              break;
+          }
 
-        if (x.settings.digits !== null) value = value.toFixed(x.settings.digits);
-        el.innerText = value;
+          if (x.settings.digits !== null) value = value.toFixed(x.settings.digits);
+          el.innerText = value;
        };
 
+       // Set up to receive crosstalk events
        var ct_sel = new crosstalk.SelectionHandle();
        ct_sel.setGroup(x.settings.crosstalk_group);
        ct_sel.on("change", function(e) {

vignettes/Minimal example.Rmd

@@ -0,0 +1,23 @@
+---
+title: "Minimal Example"
+author: "Kent S Johnson"
+date: "`r Sys.Date()`"
+output: rmarkdown::html_vignette
+vignette: >
+  %\VignetteIndexEntry{Minimal Example}
+  %\VignetteEngine{knitr::rmarkdown}
+  %\VignetteEncoding{UTF-8}
+---
+
+This is a minimal example of using a `summarywidget` _without_ `crosstalk`. This is mostly useful as a test of the `htmlwidget` character of `summarywidget`.
+
+```{r}
+library(summarywidget)
+```
+
+The `mtcars` dataset has `r summarywidget(mtcars)` rows (32).
+
+The mean mpg of four-cylinder cars is 
+`r summarywidget(mtcars, 'mean', selection=~cyl==4, column='mpg', digits=2)` mpg (26.66).
+
+`r summarywidget(mtcars, 'sum', column='am')` cars in the dataset have manual transmissions (13).

vignettes/Using summarywidget.Rmd

@@ -2,7 +2,8 @@
 title: "Using summarywidget"
 author: "Kent S Johnson"
 date: "`r Sys.Date()`"
-output: rmarkdown::html_vignette
+output: 
+  rmarkdown::html_vignette
 vignette: >
   %\VignetteIndexEntry{Using summarywidget}
   %\VignetteEngine{knitr::rmarkdown}
@@ -16,8 +17,6 @@ library(summarywidget)
 
 shared_mtcars = SharedData$new(mtcars[,c("mpg", "cyl", "hp", "am")])
 
-summarywidget(shared_mtcars)
-
 bscols(widths = c(3,NA),
   list(
     filter_checkbox("cyl", "Cylinders", shared_mtcars, ~cyl, inline = TRUE),
@@ -27,4 +26,7 @@ bscols(widths = c(3,NA),
 )
 ```
 
+### Summary
 
+You have selected `r summarywidget(shared_mtcars)` cars with an average mpg of
+`r summarywidget(shared_mtcars, 'mean', column='mpg', digits=1)`.