Add inline portal node support

README.md

@@ -115,21 +115,25 @@ How does it work under the hood?
 
 This creates a detached DOM node, with a little extra functionality attached to allow transmitting props later on.
 
-This node will contain your portal contents later, within a `<div>`, and will eventually be attached in the target location.
+This node will contain your portal contents later, and will eventually be attached in the target location.
 
-An optional options object parameter can be passed to configure the node. The only supported option is `attributes`: this can be used to set the HTML attributes (style, class, etc.) of the intermediary, like so:
+An optional options object parameter can be passed to configure the node.
 
-```javascript
-const portalNode = portals.createHtmlPortalNode({
-	attributes: { id: "div-1", style: "background-color: #aaf; width: 100px;" }
-});
-```
+- `options.containerElement` (default: `div`) can be set to `'span'` to ensure valid HTML (avoid React hydration warnings) when portaling into [phrasing content](https://developer.mozilla.org/en-US/docs/Web/HTML/Content_categories#phrasing_content).
+
+- `options.attributes` can be used to set the HTML attributes (style, class, etc.) of the intermediary, like so:
 
-The div's DOM node is also available at `.element`, so you can mutate that directly with the standard DOM APIs if preferred.
+    ```javascript
+    const portalNode = portals.createHtmlPortalNode({
+        attributes: { id: "div-1", style: "background-color: #aaf; width: 100px;" }
+    });
+    ```
+
+    The detached DOM node is also available at `.element`, so you can mutate that directly with the standard DOM APIs if preferred.
 
 ### `portals.createSvgPortalNode([options])`
 
-This creates a detached SVG DOM node. It works identically to the node from `createHtmlPortalNode`, except it will work with SVG elements. Content is placed within a `<g>` instead of a `<div>`.
+This creates a detached SVG DOM node. It works identically to the node from `createHtmlPortalNode`, except it will work with SVG elements. Content is placed within a `<g>` instead of a `<div>` by default, which can be customized by `options.containerElement`.
 
 An error will be thrown if you attempt to use a HTML node for SVG content, or a SVG node for HTML content.
 

src/index.tsx

@@ -5,12 +5,20 @@ import * as ReactDOM from 'react-dom';
 const ELEMENT_TYPE_HTML = 'html';
 const ELEMENT_TYPE_SVG  = 'svg';
 
-type ANY_ELEMENT_TYPE = typeof ELEMENT_TYPE_HTML | typeof ELEMENT_TYPE_SVG;
+type BaseOptions = {
+    attributes?: { [key: string]: string };
+};
+
+type HtmlOptions = BaseOptions & {
+    containerElement?: keyof HTMLElementTagNameMap;
+};
 
-type Options = {
-    attributes: { [key: string]: string };
+type SvgOptions = BaseOptions & {
+    containerElement?: keyof SVGElementTagNameMap;
 };
 
+type Options = HtmlOptions | SvgOptions;
+
 // ReactDOM can handle several different namespaces, but they're not exported publicly
 // https://github.com/facebook/react/blob/b87aabdfe1b7461e7331abb3601d9e6bb27544bc/packages/react-dom/src/shared/DOMNamespaces.js#L8-L10
 const SVG_NAMESPACE = 'http://www.w3.org/2000/svg';
@@ -43,23 +51,25 @@ export interface SvgPortalNode<C extends Component<any> = Component<any>> extend
 type AnyPortalNode<C extends Component<any> = Component<any>> = HtmlPortalNode<C> | SvgPortalNode<C>;
 
 
-const validateElementType = (domElement: Element, elementType: ANY_ELEMENT_TYPE) => {
+const validateElementType = (domElement: Element, elementType: typeof ELEMENT_TYPE_HTML | typeof ELEMENT_TYPE_SVG) => {
     const ownerDocument = (domElement.ownerDocument ?? document) as any;
     // Cast document to `any` because Typescript doesn't know about the legacy `Document.parentWindow` field, and also
     // doesn't believe `Window.HTMLElement`/`Window.SVGElement` can be used in instanceof tests.
     const ownerWindow = ownerDocument.defaultView ?? ownerDocument.parentWindow ?? window; // `parentWindow` for IE8 and earlier
-    if (elementType === ELEMENT_TYPE_HTML) {
-        return domElement instanceof ownerWindow.HTMLElement;
-    }
-    if (elementType === ELEMENT_TYPE_SVG) {
-        return domElement instanceof ownerWindow.SVGElement;
+
+    switch (elementType) {
+        case ELEMENT_TYPE_HTML:
+            return domElement instanceof ownerWindow.HTMLElement;
+        case ELEMENT_TYPE_SVG:
+            return domElement instanceof ownerWindow.SVGElement;
+        default:
+            throw new Error(`Unrecognized element type "${elementType}" for validateElementType.`);
     }
-    throw new Error(`Unrecognized element type "${elementType}" for validateElementType.`);
 };
 
 // This is the internal implementation: the public entry points set elementType to an appropriate value
 const createPortalNode = <C extends Component<any>>(
-    elementType: ANY_ELEMENT_TYPE,
+    elementType: typeof ELEMENT_TYPE_HTML | typeof ELEMENT_TYPE_SVG,
     options?: Options
 ): AnyPortalNode<C> => {
     let initialProps = {} as ComponentProps<C>;
@@ -68,15 +78,19 @@ const createPortalNode = <C extends Component<any>>(
     let lastPlaceholder: Node | undefined;
 
     let element;
-    if (elementType === ELEMENT_TYPE_HTML) {
-        element= document.createElement('div');
-    } else if (elementType === ELEMENT_TYPE_SVG){
-        element= document.createElementNS(SVG_NAMESPACE, 'g');
-    } else {
-        throw new Error(`Invalid element type "${elementType}" for createPortalNode: must be "html" or "svg".`);
+
+    switch (elementType) {
+        case ELEMENT_TYPE_HTML:
+            element = document.createElement(options?.containerElement ?? 'div');
+            break;
+        case ELEMENT_TYPE_SVG:
+            element = document.createElementNS(SVG_NAMESPACE, options?.containerElement ?? 'g');
+            break;
+        default:
+            throw new Error(`Invalid element type "${elementType}" for createPortalNode: must be "html" or "svg".`);
     }
 
-    if (options && typeof options === "object") {
+    if (options && typeof options === "object" && options.attributes) {
         for (const [key, value] of Object.entries(options.attributes)) {
             element.setAttribute(key, value);
         }
@@ -186,7 +200,7 @@ type OutPortalProps<C extends Component<any>> = {
 
 class OutPortal<C extends Component<any>> extends React.PureComponent<OutPortalProps<C>> {
 
-    private placeholderNode = React.createRef<HTMLDivElement>();
+    private placeholderNode = React.createRef<HTMLElement>();
     private currentPortalNode?: AnyPortalNode<C>;
 
     constructor(props: OutPortalProps<C>) {
@@ -236,15 +250,24 @@ class OutPortal<C extends Component<any>> extends React.PureComponent<OutPortalP
     render() {
         // Render a placeholder to the DOM, so we can get a reference into
         // our location in the DOM, and swap it out for the portaled node.
-        // A <div> placeholder works fine even for SVG.
-        return <div ref={this.placeholderNode} />;
+        const tagName = this.props.node.element.tagName;
+
+        // SVG tagName is lowercase and case sensitive, HTML is uppercase and case insensitive.
+        // React.createElement expects lowercase first letter to treat as non-component element.
+        // (Passing uppercase type won't break anything, but React warns otherwise:)
+        // https://github.com/facebook/react/blob/8039f1b2a05d00437cd29707761aeae098c80adc/CHANGELOG.md?plain=1#L1984
+        const type = this.props.node.elementType === ELEMENT_TYPE_HTML
+            ? tagName.toLowerCase()
+            : tagName;
+
+        return React.createElement(type, { ref: this.placeholderNode });
     }
 }
 
 const createHtmlPortalNode = createPortalNode.bind(null, ELEMENT_TYPE_HTML) as
-    <C extends Component<any> = Component<any>>(options?: Options) => HtmlPortalNode<C>;
+    <C extends Component<any> = Component<any>>(options?: HtmlOptions) => HtmlPortalNode<C>;
 const createSvgPortalNode  = createPortalNode.bind(null, ELEMENT_TYPE_SVG) as
-    <C extends Component<any> = Component<any>>(options?: Options) => SvgPortalNode<C>;
+    <C extends Component<any> = Component<any>>(options?: SvgOptions) => SvgPortalNode<C>;
 
 export {
     createHtmlPortalNode,

stories/html.stories.js

@@ -2,7 +2,7 @@ import React from 'react';
 
 import { storiesOf } from '@storybook/react';
 
-import { createHtmlPortalNode, createSvgPortalNode, InPortal, OutPortal } from '..';
+import { createHtmlPortalNode, InPortal, OutPortal } from '..';
 
 const Container = (props) =>
     <div style={{ "border": "1px solid #222", "padding": "10px" }}>
@@ -289,6 +289,64 @@ storiesOf('Portals', module)
             </div>
         });
     })
+    .add('portal container element as span in paragraph', () => {
+        const portalNode = createHtmlPortalNode({ containerElement: 'span' });
+
+        return <div>
+            <p>
+                Portal defined here:
+                <InPortal node={portalNode}>
+                    Hi!
+                </InPortal>
+            </p>
+
+            <p>
+                Portal renders here:
+                <OutPortal node={portalNode} />
+            </p>
+        </div>;
+    })
+    .add("portal container element as tr", () => {
+        const portalNode = createHtmlPortalNode({ containerElement: "tr" });
+
+        return React.createElement(() => {
+            const [useFirstTable, setUseFirstTable] = React.useState(true);
+
+            return (
+                <div>
+                <InPortal node={portalNode}>
+                    <td>Cell 1</td>
+                    <td>Cell 2</td>
+                    <td>Cell 3</td>
+                </InPortal>
+
+                <button onClick={() => setUseFirstTable(!useFirstTable)}>
+                    Move row to {useFirstTable ? "second" : "first"} table
+                </button>
+
+                <div style={{ display: "flex", gap: "20px", marginTop: "20px" }}>
+                    <table border="1">
+                    <thead>
+                        <tr>
+                        <th colSpan="3">First Table</th>
+                        </tr>
+                    </thead>
+                    <tbody>{useFirstTable && <OutPortal node={portalNode} />}</tbody>
+                    </table>
+
+                    <table border="1">
+                    <thead>
+                        <tr>
+                        <th colSpan="3">Second Table</th>
+                        </tr>
+                    </thead>
+                    <tbody>{!useFirstTable && <OutPortal node={portalNode} />}</tbody>
+                    </table>
+                </div>
+                </div>
+            );
+        });
+    })
     .add('Example from README', () => {
         const MyExpensiveComponent = () => 'expensive!';
 

tsconfig.json

@@ -8,7 +8,8 @@
         "strict": true,
         "rootDir": "./src",
         "declaration": true,
-        "declarationDir": "./dist"
+        "declarationDir": "./dist",
+        "noFallthroughCasesInSwitch": true
     },
     "include": [
         "./src/**/*.tsx"