Merge pull request #3639 from salier/select-event-plugin

Skip SelectEventPlugin extraction if no listeners

Author: Isaac Salier-Hellendag

src/browser/eventPlugins/SelectEventPlugin.js

@@ -46,6 +46,11 @@ var activeElementID = null;
 var lastSelection = null;
 var mouseDown = false;
 
+// Track whether a listener exists for this plugin. If none exist, we do
+// not extract events.
+var hasListener = false;
+var ON_SELECT_KEY = keyOf({onSelect: null});
+
 /**
  * Get an object which is a unique representation of the current selection.
  *
@@ -116,6 +121,8 @@ function constructSelectEvent(nativeEvent) {
 
     return syntheticEvent;
   }
+
+  return null;
 }
 
 /**
@@ -150,6 +157,10 @@ var SelectEventPlugin = {
       topLevelTargetID,
       nativeEvent) {
 
+    if (!hasListener) {
+      return null;
+    }
+
     switch (topLevelType) {
       // Track the input node that has focus.
       case topLevelTypes.topFocus:
@@ -187,6 +198,14 @@ var SelectEventPlugin = {
       case topLevelTypes.topKeyUp:
         return constructSelectEvent(nativeEvent);
     }
+
+    return null;
+  },
+
+  didPutListener: function(id, registrationName, listener) {
+    if (registrationName === ON_SELECT_KEY) {
+      hasListener = true;
+    }
   }
 };
 

src/browser/eventPlugins/__tests__/SelectEventPlugin-test.js

@@ -0,0 +1,101 @@
+/**
+ * Copyright 2013-2015, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @emails react-core
+ */
+
+'use strict';
+
+var mockModules = require('mock-modules');
+mockModules.mock('getActiveElement');
+
+var EventConstants;
+var React;
+var ReactMount;
+var ReactTestUtils;
+var SelectEventPlugin;
+
+var getActiveElement;
+
+var topLevelTypes;
+
+describe('SelectEventPlugin', function() {
+  function extract(node, topLevelEvent) {
+    return SelectEventPlugin.extractEvents(
+      topLevelEvent,
+      node,
+      ReactMount.getID(node),
+      {target: node}
+    );
+  }
+
+  beforeEach(function() {
+    mockModules.dumpCache();
+
+    EventConstants = require('EventConstants');
+    React = require('React');
+    ReactMount = require('ReactMount');
+    ReactTestUtils = require('ReactTestUtils');
+    SelectEventPlugin = require('SelectEventPlugin');
+
+    getActiveElement = require('getActiveElement');
+
+    topLevelTypes = EventConstants.topLevelTypes;
+  });
+
+  it('should skip extraction if no listeners are present', function() {
+    var WithoutSelect = React.createClass({
+      render: function() {
+        return <input type="text" />;
+      }
+    });
+
+    var rendered = ReactTestUtils.renderIntoDocument(<WithoutSelect />);
+    var node = React.findDOMNode(rendered);
+    getActiveElement.mockReturnValue(node);
+
+    var mousedown = extract(node, topLevelTypes.topMouseDown);
+    expect(mousedown).toBe(null);
+
+    var mouseup = extract(node, topLevelTypes.topMouseUp);
+    expect(mouseup).toBe(null);
+  });
+
+  it('should extract if an `onSelect` listener is present', function() {
+    var mocks = require('mocks');
+
+    var WithSelect = React.createClass({
+      render: function() {
+        return <input type="text" onSelect={this.props.onSelect} />;
+      }
+    });
+
+    var cb = mocks.getMockFunction();
+
+    var rendered = ReactTestUtils.renderIntoDocument(
+      <WithSelect onSelect={cb} />
+    );
+    var node = React.findDOMNode(rendered);
+
+    node.selectionStart = 0;
+    node.selectionEnd = 0;
+    getActiveElement.mockReturnValue(node);
+
+    var focus = extract(node, topLevelTypes.topFocus);
+    expect(focus).toBe(null);
+
+    var mousedown = extract(node, topLevelTypes.topMouseDown);
+    expect(mousedown).toBe(null);
+
+    var mouseup = extract(node, topLevelTypes.topMouseUp);
+    expect(mouseup).not.toBe(null);
+    expect(typeof mouseup).toBe('object');
+    expect(mouseup.type).toBe('select');
+    expect(mouseup.target).toBe(node);
+  });
+});