[added] Ability for modal to be appended to arbitrary elements (react…

…js#183)

* The ability to specify the parent via a selector

* Using object to denote dom element

* allow only function as parentSelector

* update README

* Fix parent selector type and default value

README.md

@@ -73,6 +73,26 @@ This doesn't affect styling as no styles are applied to this element by default.
 The default styles above are available on `Modal.defaultStyles`. Changes to this
 object will apply to all instances of the modal.
 
+### Appended to custom node
+You can choose an element for the modal to be appended to, rather than using
+body tag. To do this, provide a function to `parentSelector` prop that return
+the element to be used.
+
+```jsx
+
+function getParent() {
+  return document.querySelector('#root');
+}
+
+<Modal
+  ...
+  parentSelector={getParent}
+  ...
+>
+  <p>Modal Content.</p>
+</Modal>
+```
+
 ### Body class
 When the modal is opened a `ReactModal__Body--open` class is added to the `body` tag.
 You can use this to remove scrolling on the the body while the modal is open.

lib/components/Modal.js

@@ -10,6 +10,10 @@ var Assign = require('lodash.assign');
 var SafeHTMLElement = ExecutionEnvironment.canUseDOM ? window.HTMLElement : {};
 var AppElement = ExecutionEnvironment.canUseDOM ? document.body : {appendChild: function() {}};
 
+function getParentElement(parentSelector) {
+  return parentSelector();
+}
+
 var Modal = React.createClass({
 
   displayName: 'Modal',
@@ -37,6 +41,7 @@ var Modal = React.createClass({
     closeTimeoutMS: React.PropTypes.number,
     ariaHideApp: React.PropTypes.bool,
     shouldCloseOnOverlayClick: React.PropTypes.bool,
+    parentSelector: React.PropTypes.func,
     role: React.PropTypes.string,
     contentLabel: React.PropTypes.string.isRequired
   },
@@ -47,18 +52,29 @@ var Modal = React.createClass({
       portalClassName: 'ReactModalPortal',
       ariaHideApp: true,
       closeTimeoutMS: 0,
-      shouldCloseOnOverlayClick: true
+      shouldCloseOnOverlayClick: true,
+      parentSelector: () => document.body
     };
   },
 
   componentDidMount: function() {
     this.node = document.createElement('div');
     this.node.className = this.props.portalClassName;
-    document.body.appendChild(this.node);
+
+    var parent = getParentElement(this.props.parentSelector);
+    parent.appendChild(this.node);
     this.renderPortal(this.props);
   },
 
   componentWillReceiveProps: function(newProps) {
+    var currentParent = getParentElement(this.props.parentSelector);
+    var newParent = getParentElement(newProps.parentSelector);
+
+    if(newParent !== currentParent) {
+      currentParent.removeChild(this.node);
+      newParent.appendChild(this.node);
+    }
+
     this.renderPortal(newProps);
   },
 
@@ -68,7 +84,8 @@ var Modal = React.createClass({
     }
 
     ReactDOM.unmountComponentAtNode(this.node);
-    document.body.removeChild(this.node);
+    var parent = getParentElement(this.props.parentSelector);
+    parent.removeChild(this.node);
     elementClass(document.body).remove('ReactModal__Body--open');
   },