change position:relative for htmlwidget div container so tooltip work

inst/examples/test_multiple_shiny.R

@@ -0,0 +1,44 @@
+# silly test to check multiple radviz on a page
+#   and make sure tooltips work as expected
+
+library(shiny)
+library(radviz)
+
+ui <- fluidPage(
+ fluidRow(
+   column(
+     width = 6,
+     radvizOutput("radviz1")
+   ),
+   column(
+     width = 6,
+     radvizOutput("radviz2")
+   )
+ ) 
+)
+
+server <- function(input,output,session){
+  output$radviz1 <- renderRadviz({
+    radviz(iris, diameter=400, margin=100, 
+           use_repulsion=TRUE, draw_links=TRUE, 
+           width=400, height=500
+    ) %>% 
+      add_dimensions(c('Sepal.Length', 'Sepal.Width', 
+                       'Petal.Length', 'Petal.Width')) %>% 
+      add_color("Species") %>% 
+      add_tooltip("function(d){ return 'Petal width: ' + d['Petal.Length']; }")
+  })
+
+  output$radviz2 <- renderRadviz({
+    radviz(iris, diameter=400, margin=100, 
+           use_repulsion=TRUE, draw_links=TRUE, 
+           width=400, height=500
+    ) %>% 
+      add_dimensions(c('Sepal.Length', 'Sepal.Width', 
+                       'Petal.Length', 'Petal.Width')) %>% 
+      add_color("Species") %>% 
+      add_tooltip("function(d){ return 'Petal width: ' + d['Petal.Length']; }")
+  })
+}
+
+shinyApp(ui,server)

inst/htmlwidgets/radviz.js

@@ -10,6 +10,17 @@ HTMLWidgets.widget({
     return {
 
       renderValue: function(x) {
+
+        /* fix multiple tooltip problem
+            for standalone we will need to explicitly
+            assign position : relative for our
+            htmlwidget container div
+            since radviz tooltip needs absolute positioning
+            
+          I tested in tagList, rmarkdown, and shiny
+        */
+        el.style.position = "relative";
+
 
         var data = HTMLWidgets.dataframeToD3(x.data);