Plugins: Allow retrieving form values from dialogs

packages/app-desktop/services/plugins/UserWebview.tsx

@@ -1,5 +1,5 @@
 import * as React from 'react';
-import { useRef, useEffect, useState } from 'react';
+import { useRef, useEffect, useState, useImperativeHandle, forwardRef } from 'react';
 import useViewIsReady from './hooks/useViewIsReady';
 import useThemeCss from './hooks/useThemeCss';
 const styled = require('styled-components').default;
@@ -32,7 +32,29 @@ const StyledFrame = styled.iframe`
 	border-bottom: ${(props: Props) => props.borderBottom ? `1px solid ${props.theme.dividerColor}` : 'none'};
 `;
 
-export default function UserWebview(props: Props) {
+function serializeForm(form: any) {
+	const output: any = {};
+	const formData = new FormData(form);
+	for (const key of formData.keys()) {
+		output[key] = formData.get(key);
+	}
+	return output;
+}
+
+function serializeForms(document: any) {
+	const forms = document.getElementsByTagName('form');
+	const output: any = {};
+	let untitledIndex = 0;
+
+	for (const form of forms) {
+		const name = `${form.getAttribute('name')}` || (`form${untitledIndex++}`);
+		output[name] = serializeForm(form);
+	}
+
+	return output;
+}
+
+function UserWebview(props: Props, ref: any) {
 	const minWidth = props.minWidth ? props.minWidth : 200;
 	const minHeight = props.minHeight ? props.minHeight : 20;
 
@@ -41,6 +63,18 @@ export default function UserWebview(props: Props) {
 	const cssFilePath = useThemeCss({ pluginId: props.pluginId, themeId: props.themeId });
 	const [contentSize, setContentSize] = useState<Size>({ width: minWidth, height: minHeight });
 
+	useImperativeHandle(ref, () => {
+		return {
+			formData: function() {
+				if (viewRef.current) {
+					return serializeForms(viewRef.current.contentWindow.document);
+				} else {
+					return null;
+				}
+			},
+		};
+	});
+
 	function frameWindow() {
 		if (!viewRef.current) return null;
 		return viewRef.current.contentWindow;
@@ -143,3 +177,5 @@ export default function UserWebview(props: Props) {
 		borderBottom={props.borderBottom}
 	></StyledFrame>;
 }
+
+export default forwardRef(UserWebview);

packages/app-desktop/services/plugins/UserWebviewDialog.tsx

@@ -1,7 +1,8 @@
-import { ButtonSpec } from '@joplin/lib/services/plugins/api/types';
+import { ButtonSpec, DialogResult } from '@joplin/lib/services/plugins/api/types';
 import PluginService from '@joplin/lib/services/plugins/PluginService';
 import WebviewController from '@joplin/lib/services/plugins/WebviewController';
 import * as React from 'react';
+import { useRef } from 'react';
 import UserWebview, { Props as UserWebviewProps } from './UserWebview';
 import UserWebviewDialogButtonBar from './UserWebviewDialogButtonBar';
 const styled = require('styled-components').default;
@@ -49,6 +50,8 @@ function defaultButtons(): ButtonSpec[] {
 }
 
 export default function UserWebviewDialog(props: Props) {
+	const webviewRef = useRef(null);
+
 	function viewController(): WebviewController {
 		return PluginService.instance().pluginById(props.pluginId).viewController(props.viewId) as WebviewController;
 	}
@@ -57,7 +60,10 @@ export default function UserWebviewDialog(props: Props) {
 		return {
 			...b,
 			onClick: () => {
-				viewController().closeWithResponse(b.id);
+				const response: DialogResult = { id: b.id };
+				const formData = webviewRef.current.formData();
+				if (formData && Object.keys(formData).length) response.formData = formData;
+				viewController().closeWithResponse(response);
 			},
 		};
 	});
@@ -67,6 +73,7 @@ export default function UserWebviewDialog(props: Props) {
 			<Dialog>
 				<UserWebViewWrapper>
 					<UserWebview
+						ref={webviewRef}
 						html={props.html}
 						scripts={props.scripts}
 						onMessage={props.onMessage}