const React = require('react');
const Component = React.Component;
const { Platform, View, Text } = require('react-native');
const { WebView } = require('react-native-webview');
const { themeStyle } = require('lib/components/global-style.js');
const Setting = require('lib/models/Setting.js');
const { reg } = require('lib/registry.js');
const { shim } = require('lib/shim');
const { assetsToHeaders } = require('lib/joplin-renderer');
const shared = require('lib/components/shared/note-screen-shared.js');
const markupLanguageUtils = require('lib/markupLanguageUtils');
import Async from 'react-async';
class NoteBodyViewer extends Component {
constructor() {
super();
this.state = {
resources: {},
webViewLoaded: false,
bodyHtml: '',
};
this.forceUpdate_ = false;
this.isMounted_ = false;
this.markupToHtml_ = markupLanguageUtils.newMarkupToHtml();
this.reloadNote = this.reloadNote.bind(this);
this.watchFn = this.watchFn.bind(this);
}
componentDidMount() {
this.isMounted_ = true;
}
componentWillUnmount() {
this.markupToHtml_ = null;
this.isMounted_ = false;
}
async reloadNote() {
this.forceUpdate_ = false;
const note = this.props.note;
const theme = themeStyle(this.props.theme);
const bodyToRender = note ? note.body : '';
const mdOptions = {
onResourceLoaded: () => {
if (this.resourceLoadedTimeoutId_) {
clearTimeout(this.resourceLoadedTimeoutId_);
this.resourceLoadedTimeoutId_ = null;
}
this.resourceLoadedTimeoutId_ = setTimeout(() => {
this.resourceLoadedTimeoutId_ = null;
this.forceUpdate();
}, 100);
},
highlightedKeywords: this.props.highlightedKeywords,
resources: this.props.noteResources, // await shared.attachedResources(bodyToRender),
codeTheme: theme.codeThemeCss,
postMessageSyntax: 'window.ReactNativeWebView.postMessage',
};
const result = await this.markupToHtml_.render(
note.markup_language,
bodyToRender,
{
bodyPaddingTop: '.8em', // Extra top padding on the rendered MD so it doesn't touch the border
bodyPaddingBottom: this.props.paddingBottom, // Extra bottom padding to make it possible to scroll past the action button (so that it doesn't overlap the text)
...this.props.webViewStyle,
},
mdOptions
);
let html = result.html;
const resourceDownloadMode = Setting.value('sync.resourceDownloadMode');
const injectedJs = [];
injectedJs.push(shim.injectedJs('webviewLib'));
injectedJs.push('webviewLib.initialize({ postMessage: msg => { return window.ReactNativeWebView.postMessage(msg); } });');
injectedJs.push(`
const readyStateCheckInterval = setInterval(function() {
if (document.readyState === "complete") {
clearInterval(readyStateCheckInterval);
if ("${resourceDownloadMode}" === "manual") webviewLib.setupResourceManualDownload();
const hash = "${this.props.noteHash}";
// Gives it a bit of time before scrolling to the anchor
// so that images are loaded.
if (hash) {
setTimeout(() => {
const e = document.getElementById(hash);
if (!e) {
console.warn('Cannot find hash', hash);
return;
}
e.scrollIntoView();
}, 500);
}
}
}, 10);
`);
html =
`
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
${assetsToHeaders(result.pluginAssets, { asHtml: true })}
</head>
<body>
${html}
</body>
</html>
`;
// On iOS scalesPageToFit work like this:
//
// Find the widest image, resize it *and everything else* by x% so that
// the image fits within the viewport. The problem is that it means if there's
// a large image, everything is going to be scaled to a very small size, making
// the text unreadable.
//
// On Android:
//
// Find the widest elements and scale them (and them only) to fit within the viewport
// It means it's going to scale large images, but the text will remain at the normal
// size.
//
// That means we can use scalesPageToFix on Android but not on iOS.
// The weird thing is that on iOS, scalesPageToFix=false along with a CSS
// rule "img { max-width: 100% }", works like scalesPageToFix=true on Android.
// So we use scalesPageToFix=false on iOS along with that CSS rule.
// `baseUrl` is where the images will be loaded from. So images must use a path relative to resourceDir.
return {
source: {
html: html,
baseUrl: `file://${Setting.value('resourceDir')}/`,
},
injectedJs: injectedJs,
};
}
onLoadEnd() {
setTimeout(() => {
if (this.props.onLoadEnd) this.props.onLoadEnd();
}, 100);
if (this.state.webViewLoaded) return;
// Need to display after a delay to avoid a white flash before
// the content is displayed.
setTimeout(() => {
if (!this.isMounted_) return;
this.setState({ webViewLoaded: true });
}, 100);
}
shouldComponentUpdate(nextProps, nextState) {
const safeGetNoteProp = (props, propName) => {
if (!props) return null;
if (!props.note) return null;
return props.note[propName];
};
// To address https://github.com/laurent22/joplin/issues/433
// If a checkbox in a note is ticked, the body changes, which normally would trigger a re-render
// of this component, which has the unfortunate side effect of making the view scroll back to the top.
// This re-rendering however is uncessary since the component is already visually updated via JS.
// So here, if the note has not changed, we prevent the component from updating.
// This fixes the above issue. A drawback of this is if the note is updated via sync, this change
// will not be displayed immediately.
const currentNoteId = safeGetNoteProp(this.props, 'id');
const nextNoteId = safeGetNoteProp(nextProps, 'id');
if (currentNoteId !== nextNoteId || nextState.webViewLoaded !== this.state.webViewLoaded) return true;
// If the length of the body has changed, then it's something other than a checkbox that has changed,
// for example a resource that has been attached to the note while in View mode. In that case, update.
return (`${safeGetNoteProp(this.props, 'body')}`).length !== (`${safeGetNoteProp(nextProps, 'body')}`).length;
}
rebuildMd() {
this.forceUpdate_ = true;
this.forceUpdate();
}
watchFn() {
// react-async will not fetch the data again after the first render
// so we use this watchFn function to force it to reload in certain
// cases. It is used in particular when re-rendering the note when
// a resource has been downloaded in auto mode.
return this.forceUpdate_;
}
render() {
// Note: useWebKit={false} is needed to go around this bug:
// https://github.com/react-native-community/react-native-webview/issues/376
// However, if we add the <meta> tag as described there, it is no longer necessary and WebKit can be used!
// https://github.com/react-native-community/react-native-webview/issues/312#issuecomment-501991406
//
// However, on iOS, due to the bug below, we cannot use WebKit:
// https://github.com/react-native-community/react-native-webview/issues/312#issuecomment-503754654
const webViewStyle = { backgroundColor: this.props.webViewStyle.backgroundColor };
// On iOS, the onLoadEnd() event is never fired so always
// display the webview (don't do the little trick
// to avoid the white flash).
if (Platform.OS !== 'ios') {
webViewStyle.opacity = this.state.webViewLoaded ? 1 : 0.01;
}
return (
<View style={this.props.style}>
<Async promiseFn={this.reloadNote} watchFn={this.watchFn}>
{({ data, error, isPending }) => {
if (error) {
console.error(error);
return <Text>{error.message}</Text>;
}
if (isPending) return null;
return (
<WebView
useWebKit={Platform.OS !== 'ios'}
style={webViewStyle}
source={data.source}
injectedJavaScript={data.injectedJs.join('\n')}
originWhitelist={['file://*', './*', 'http://*', 'https://*']}
mixedContentMode="always"
allowFileAccess={true}
onLoadEnd={() => this.onLoadEnd()}
onError={() => reg.logger().error('WebView error')}
onMessage={event => {
// Since RN 58 (or 59) messages are now escaped twice???
let msg = unescape(unescape(event.nativeEvent.data));
console.info('Got IPC message: ', msg);
if (msg.indexOf('checkboxclick:') === 0) {
const newBody = shared.toggleCheckbox(msg, this.props.note.body);
if (this.props.onCheckboxChange) this.props.onCheckboxChange(newBody);
} else if (msg.indexOf('markForDownload:') === 0) {
msg = msg.split(':');
const resourceId = msg[1];
if (this.props.onMarkForDownload) this.props.onMarkForDownload({ resourceId: resourceId });
} else {
this.props.onJoplinLinkClick(msg);
}
}}
/>
);
}}
</Async>
</View>
);
}
}
module.exports = { NoteBodyViewer };