only render editor page controls/previews on change

src/components/PreviewPane/Preview.js

@@ -9,15 +9,18 @@ const style = {
   fontFamily: 'Roboto, "Helvetica Neue", HelveticaNeue, Helvetica, Arial, sans-serif',
 };
 
-export default function Preview({ collection, fields, widgetFor }) {
-  if (!collection || !fields) {
-    return null;
+export default class Preview extends React.Component {
+  render() {
+    const { collection, fields, widgetFor } = this.props;
+    if (!collection || !fields) {
+      return null;
+    }
+    return (
+      <div style={style}>
+        {fields.filter(isVisible).map(field => widgetFor(field.get('name')))}
+      </div>
+    );
   }
-  return (
-    <div style={style}>
-      {fields.filter(isVisible).map(field => widgetFor(field.get('name')))}
-    </div>
-  );
 }
 
 Preview.propTypes = {

src/components/PreviewPane/PreviewContent.js

@@ -0,0 +1,22 @@
+import React, { PropTypes } from 'react';
+import { ScrollSyncPane } from '../ScrollSync';
+
+// We need to create a lightweight component here so that we can
+// access the context within the Frame. This allows us to attach
+// the ScrollSyncPane to the body.
+class PreviewContent extends React.Component {
+  render() {
+    const { previewComponent, previewProps } = this.props;
+    return (
+      <ScrollSyncPane attachTo={this.context.document.scrollingElement}>
+        {React.createElement(previewComponent, previewProps)}
+      </ScrollSyncPane>
+    );
+  }
+}
+
+PreviewContent.contextTypes = {
+  document: PropTypes.any,
+};
+
+export default PreviewContent;

src/components/PreviewPane/PreviewPane.js

@@ -2,11 +2,12 @@ import React, { PropTypes } from 'react';
 import { List, Map } from 'immutable';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import Frame from 'react-frame-component';
-import { ScrollSyncPane } from '../ScrollSync';
 import registry from '../../lib/registry';
 import { resolveWidget } from '../Widgets';
 import { selectTemplateName, selectInferedField } from '../../reducers/collections';
 import { INFERABLE_FIELDS } from '../../constants/fieldInference';
+import PreviewContent from './PreviewContent.js';
+import PreviewHOC from '../Widgets/PreviewHOC';
 import Preview from './Preview';
 import styles from './PreviewPane.css';
 
@@ -16,15 +17,18 @@ export default class PreviewPane extends React.Component {
     const { fieldsMetaData, getAsset, entry } = props;
     const widget = resolveWidget(field.get('widget'));
 
-    return !widget.preview ? null : React.createElement(widget.preview, {
-      field,
-      key: field.get('name'),
-      value: value && Map.isMap(value) ? value.get(field.get('name')) : value,
-      metadata: fieldsMetaData && fieldsMetaData.get(field.get('name')),
-      getAsset,
-      entry,
-      fieldsMetaData,
-    });
+    return !widget.preview ? null : (
+      <PreviewHOC
+        previewComponent={widget.preview}
+        key={field.get('name')}
+        field={field}
+        getAsset={getAsset}
+        value={value && Map.isMap(value) ? value.get(field.get('name')) : value}
+        metadata={fieldsMetaData && fieldsMetaData.get(field.get('name'))}
+        entry={entry}
+        fieldsMetaData={fieldsMetaData}
+      />
+    );
   };
 
   inferedFields = {};
@@ -118,7 +122,9 @@ export default class PreviewPane extends React.Component {
       return null;
     }
 
-    const component = registry.getPreviewTemplate(selectTemplateName(collection, entry.get('slug'))) || Preview;
+    const previewComponent =
+      registry.getPreviewTemplate(selectTemplateName(collection, entry.get('slug'))) ||
+      Preview;
 
     this.inferFields();
 
@@ -135,18 +141,6 @@ export default class PreviewPane extends React.Component {
       return <Frame className={styles.frame} head={styleEls} />;
     }
 
-    // We need to create a lightweight component here so that we can
-    // access the context within the Frame. This allows us to attach
-    // the ScrollSyncPane to the body.
-    const PreviewContent = (props, { document: iFrameDocument }) => (
-      <ScrollSyncPane attachTo={iFrameDocument.scrollingElement}>
-        {React.createElement(component, previewProps)}
-      </ScrollSyncPane>);
-
-    PreviewContent.contextTypes = {
-      document: PropTypes.any,
-    };
-
     return (<Frame
       className={styles.frame}
       head={styleEls}
@@ -156,7 +150,7 @@ export default class PreviewPane extends React.Component {
   <head><base target="_blank"/></head>
   <body><div></div></body>
 </html>`}
-    ><PreviewContent /></Frame>);
+    ><PreviewContent {...{ previewComponent, previewProps }}/></Frame>);
   }
 }
 

src/components/Widgets/ControlHOC.js

@@ -22,6 +22,10 @@ class ControlHOC extends Component {
     getAsset: PropTypes.func.isRequired,
   };
 
+  shouldComponentUpdate(nextProps) {
+    return nextProps.value !== this.props.value;
+  }
+
   processInnerControlRef = (wrappedControl) => {
     if (!wrappedControl) return;
     this.wrappedControlValid = wrappedControl.isValid || truthy;

src/components/Widgets/MarkdownControl/VisualEditor/index.js

@@ -166,6 +166,7 @@ const RULES = [
       }
     },
   },
+  /*
   {
     // Special case for links, to grab their href.
     deserialize(el, next) {
@@ -180,6 +181,7 @@ const RULES = [
       }
     },
   },
+  */
 ]
 
 const serializer = new SlateHtml({ rules: RULES });

src/components/Widgets/PreviewHOC.js

@@ -0,0 +1,14 @@
+import React from 'react';
+
+class PreviewHOC extends React.Component {
+  shouldComponentUpdate(nextProps) {
+    return nextProps.value !== this.props.value;
+  }
+
+  render() {
+    const { previewComponent, ...props } = this.props;
+    return React.createElement(previewComponent, props);
+  }
+}
+
+export default PreviewHOC;