Fix handling of circular references

blink1073 · blink1073 · commit a89ec047ded2 · 2015-02-15T09:23:14.000-06:00
diff --git a/lib/matplotlib/backends/backend_webagg_core.py b/lib/matplotlib/backends/backend_webagg_core.py
@@ -271,6 +271,8 @@ def get_renderer(self, cleared=None):
 
     def handle_event(self, event):
         e_type = event['type']
+        guiEvent = event.get('guiEvent', None)
+
         if e_type == 'ack':
             # Network latency tends to decrease if traffic is flowing
             # in both directions.  Therefore, the browser sends back
@@ -290,7 +292,6 @@ def handle_event(self, event):
             # Javascript button numbers and matplotlib button numbers are
             # off by 1
             button = event['button'] + 1
-            guiEvent = event['guiEvent']
 
             # The right mouse button pops up a context menu, which
             # doesn't work very well, so use the middle mouse button
diff --git a/lib/matplotlib/backends/web_backend/mpl.js b/lib/matplotlib/backends/web_backend/mpl.js
@@ -454,6 +454,18 @@ mpl.findpos = function(e) {
     return {"x": x, "y": y};
 };
 
+/*
+ * return a copy of an object with only non-object keys
+ * we need this to avoid circular references
+ * http://stackoverflow.com/a/24161582/3208463
+ */
+function simpleKeys (original) {
+  return Object.keys(original).reduce(function (obj, key) {
+    obj[key] = typeof original[key] === 'object' ? '{ ... }' : original[key];
+    return obj;
+  }, {});
+}
+
 mpl.figure.prototype.mouse_event = function(event, name) {
     var canvas_pos = mpl.findpos(event)
 
@@ -468,7 +480,7 @@ mpl.figure.prototype.mouse_event = function(event, name) {
 
     this.send_message(name, {x: x, y: y, button: event.button,
                              step: event.step,
-                             guiEvent: event});
+                             guiEvent: simpleKeys(event)});
 
     /* This prevents the web browser from automatically changing to
      * the text insertion cursor when the button is pressed.  We want
@@ -509,7 +521,7 @@ mpl.figure.prototype.key_event = function(event, name) {
     this._key_event_extra(event, name);
 
     this.send_message(name, {key: value,
-                             guiEvent: event});
+                             guiEvent: simpleKeys(event)});
     return false;
 }
 
