fix for d3 v3.0

Author: benfred

package.json

@@ -1,6 +1,6 @@
 {
   "name": "venn.js",
-  "version": "0.2.11",
+  "version": "0.2.12",
   "author": "Ben Frederickson <ben@benfrederickson.com> (http:/www.benfrederickson.com)",
   "url": "https://github.com/benfred/venn.js/issues",
   "devDependencies": {

src/diagram.js

@@ -147,7 +147,13 @@ export function VennDiagram() {
 
         if (wrap) {
             if (hasPrevious) {
-                updateText.on("end", wrapText(circles, label));
+                // d3 4.0 uses 'on' for events on transitions,
+                // but d3 3.0 used 'each' instead. switch appropiately
+                if ('on' in updateText) {
+                    updateText.on("end", wrapText(circles, label));
+                } else {
+                    updateText.each("end", wrapText(circles, label));
+                }
             } else {
                 updateText.each(wrapText(circles, label));
             }

venn.js

@@ -1340,7 +1340,13 @@
 
             if (wrap) {
                 if (hasPrevious) {
-                    updateText.on("end", wrapText(circles, label));
+                    // d3 4.0 uses 'on' for events on transitions,
+                    // but d3 3.0 used 'each' instead. switch appropiately
+                    if ('on' in updateText) {
+                        updateText.on("end", wrapText(circles, label));
+                    } else {
+                        updateText.each("end", wrapText(circles, label));
+                    }
                 } else {
                     updateText.each(wrapText(circles, label));
                 }