bug #269 Allow SVG elements in LiveComponent (norkunas)

This PR was merged into the 2.x branch.

Discussion
----------

Allow SVG elements in LiveComponent

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| Tickets       | N/A
| License       | MIT

When the component contains svg elements then it throws error on rerender:
```
Uncaught (in promise) Error: Could not clone element
    at cloneHTMLElement (live_controller.js:977:15)
    at onBeforeElUpdated (live_controller.js:1331:46)
    at morphEl (live_controller.js:492:21)
    at morphChildren (live_controller.js:605:33)
    at morphEl (live_controller.js:507:15)
    at morphChildren (live_controller.js:605:33)
    at morphEl (live_controller.js:507:15)
    at morphChildren (live_controller.js:605:33)
    at morphEl (live_controller.js:507:15)
    at morphdom (live_controller.js:722:13)
```

Commits
-------

c25f021 Allow SVG elements in LiveComponent

Author: weaverryan

src/LiveComponent/assets/dist/live_controller.js

@@ -1080,6 +1080,9 @@ class default_1 extends Controller {
         return element.dataset.value || element.value;
     }
     _updateModelFromElement(element, value, shouldRender) {
+        if (!(element instanceof HTMLElement)) {
+            throw new Error('Could not update model for non HTMLElement');
+        }
         const model = element.dataset.model || element.getAttribute('name');
         if (!model) {
             const clonedElement = cloneHTMLElement(element);
@@ -1273,7 +1276,7 @@ class default_1 extends Controller {
     _getLoadingDirectives() {
         const loadingDirectives = [];
         this.element.querySelectorAll('[data-loading]').forEach((element => {
-            if (!(element instanceof HTMLElement)) {
+            if (!(element instanceof HTMLElement) && !(element instanceof SVGElement)) {
                 throw new Error('Invalid Element Type');
             }
             const directives = parseDirectives(element.dataset.loading || 'show');
@@ -1327,6 +1330,9 @@ class default_1 extends Controller {
         const newElement = htmlToElement(newHtml);
         morphdom(this.element, newElement, {
             onBeforeElUpdated: (fromEl, toEl) => {
+                if (!(fromEl instanceof HTMLElement) || !(toEl instanceof HTMLElement)) {
+                    return false;
+                }
                 if (fromEl.isEqualNode(toEl)) {
                     const normalizedFromEl = cloneHTMLElement(fromEl);
                     normalizeAttributesForComparison(normalizedFromEl);

src/LiveComponent/assets/src/live_controller.ts

@@ -8,7 +8,7 @@ import { normalizeAttributesForComparison } from './normalize_attributes_for_com
 import { cloneHTMLElement } from './clone_html_element';
 
 interface ElementLoadingDirectives {
-    element: HTMLElement,
+    element: HTMLElement|SVGElement,
     directives: Directive[]
 }
 
@@ -190,11 +190,15 @@ export default class extends Controller {
         this._makeRequest(null);
     }
 
-    _getValueFromElement(element: HTMLElement) {
+    _getValueFromElement(element: HTMLElement|SVGElement) {
         return element.dataset.value || (element as any).value;
     }
 
-    _updateModelFromElement(element: HTMLElement, value: string, shouldRender: boolean) {
+    _updateModelFromElement(element: Element, value: string, shouldRender: boolean) {
+        if (!(element instanceof HTMLElement)) {
+            throw new Error('Could not update model for non HTMLElement');
+        }
+
         const model = element.dataset.model || element.getAttribute('name');
 
         if (!model) {
@@ -419,7 +423,7 @@ export default class extends Controller {
     /**
      * @private
      */
-    _handleLoadingDirective(element: HTMLElement, isLoading: boolean, directive: Directive) {
+    _handleLoadingDirective(element: HTMLElement|SVGElement, isLoading: boolean, directive: Directive) {
         const finalAction = parseLoadingAction(directive.action, isLoading);
 
         let loadingDirective: (() => void);
@@ -490,7 +494,7 @@ export default class extends Controller {
         const loadingDirectives: ElementLoadingDirectives[] = [];
 
         this.element.querySelectorAll('[data-loading]').forEach((element => {
-            if (!(element instanceof HTMLElement)) {
+            if (!(element instanceof HTMLElement) && !(element instanceof SVGElement)) {
                 throw new Error('Invalid Element Type');
             }
 
@@ -506,19 +510,19 @@ export default class extends Controller {
         return loadingDirectives;
     }
 
-    _showElement(element: HTMLElement) {
+    _showElement(element: HTMLElement|SVGElement) {
         element.style.display = 'inline-block';
     }
 
-    _hideElement(element: HTMLElement) {
+    _hideElement(element: HTMLElement|SVGElement) {
         element.style.display = 'none';
     }
 
-    _addClass(element: HTMLElement, classes: string[]) {
+    _addClass(element: HTMLElement|SVGElement, classes: string[]) {
         element.classList.add(...combineSpacedArray(classes));
     }
 
-    _removeClass(element: HTMLElement, classes: string[]) {
+    _removeClass(element: HTMLElement|SVGElement, classes: string[]) {
         element.classList.remove(...combineSpacedArray(classes));
 
         // remove empty class="" to avoid morphdom "diff" problem
@@ -564,6 +568,10 @@ export default class extends Controller {
         const newElement = htmlToElement(newHtml);
         morphdom(this.element, newElement, {
             onBeforeElUpdated: (fromEl, toEl) => {
+                if (!(fromEl instanceof HTMLElement) || !(toEl instanceof HTMLElement)) {
+                    return false;
+                }
+
                 // https://github.com/patrick-steele-idem/morphdom#can-i-make-morphdom-blaze-through-the-dom-tree-even-faster-yes
                 if (fromEl.isEqualNode(toEl)) {
                     // the nodes are equal, but the "value" on some might differ

src/LiveComponent/assets/test/clone_html_element.test.ts

@@ -0,0 +1,23 @@
+import { cloneHTMLElement } from '../src/clone_html_element';
+
+const createElement = function(html: string): HTMLElement {
+    const template = document.createElement('template');
+    html = html.trim();
+    template.innerHTML = html;
+
+    const child = template.content.firstChild;
+    if (!child || !(child instanceof HTMLElement)) {
+        throw new Error('Child not found');
+    }
+
+    return child;
+}
+
+describe('cloneHTMLElement', () => {
+    it('allows to clone HTMLElement', () => {
+        const element = createElement('<div class="foo"></div>');
+        const clone = cloneHTMLElement(element);
+
+        expect(clone.outerHTML).toEqual('<div class="foo"></div>');
+    });
+});