Refactored embedded image/video code and prevented them from being displayed on deleted posts

web/react/components/post_image.jsx

@@ -0,0 +1,62 @@
+// Copyright (c) 2015 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+export default class PostImageEmbed extends React.Component {
+    constructor(props) {
+        super(props);
+
+        this.state = {
+            loaded: false
+        };
+    }
+
+    componentWillMount() {
+        this.loadImg(this.props.link);
+    }
+
+    componentWillReceiveProps(nextProps) {
+        if (nextProps.link !== this.props.link) {
+            this.setState({
+                loaded: false
+            });
+        }
+    }
+
+    componentDidUpdate(prevProps) {
+        if (!this.state.loaded && prevProps.link !== this.props.link) {
+            this.loadImg(this.props.link);
+        }
+    }
+
+    loadImg(src) {
+        const img = new Image();
+        img.onload = () => {
+            this.setState({
+                loaded: true
+            });
+        };
+        img.src = src;
+    }
+
+    render() {
+        if (!this.state.loaded) {
+            return (
+                <img
+                    className='img-div placeholder'
+                    height='500px'
+                />
+            );
+        }
+
+        return (
+            <img
+                className='img-div'
+                src={this.props.link}
+            />
+        );
+    }
+}
+
+PostImageEmbed.propTypes = {
+    link: React.PropTypes.string.isRequired
+};