react-native/Examples/UIExplorer/js/WebViewExample.js
Luke Miles da9a712a9e Add a injectJavaScript method to the WebView component
Summary:
Currently, < WebView > allows you to pass JS to execute within the view. This works great, but there currently is not a way to execute JS after the page is loaded. We needed this for our app.

We noticed that the WebView had messaging support added (see #9762) . Initially, this seemed like more than enough functionality for our use case - just write a function that's injected on initial load that accepts a message with JS, and `eval()` it. However, this broke once we realized that Content Security Policy can block the use of eval on pages. The native methods iOS provide to inject JS allow you to inject JS without CSP interfering. So, we just wrapped the native methods on iOS (and later Android) and it worked for our use case. The method injectJavaScript was born.

Now, after I wrote this code, I realized that #8798 exists and hadn't been merged because of a lack of tests. I commend what was done in #8798 as it sorely solves a problem (injecting JS after the initial load) and has more features than what I'
Closes https://github.com/facebook/react-native/pull/11358

Differential Revision: D4390425

fbshipit-source-id: 02813127f8cf60fd84229cb26eeea7f8922d03b3
2017-01-06 20:29:02 -08:00

480 lines
11 KiB
JavaScript

/**
* Copyright (c) 2013-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* The examples provided by Facebook are for non-commercial testing and
* evaluation purposes only.
*
* Facebook reserves all rights not expressly granted.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL
* FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* @flow
*/
'use strict';
var React = require('react');
var ReactNative = require('react-native');
var {
StyleSheet,
Text,
TextInput,
TouchableWithoutFeedback,
TouchableOpacity,
View,
WebView
} = ReactNative;
var HEADER = '#3b5998';
var BGWASH = 'rgba(255,255,255,0.8)';
var DISABLED_WASH = 'rgba(255,255,255,0.25)';
var TEXT_INPUT_REF = 'urlInput';
var WEBVIEW_REF = 'webview';
var DEFAULT_URL = 'https://m.facebook.com';
class WebViewExample extends React.Component {
state = {
url: DEFAULT_URL,
status: 'No Page Loaded',
backButtonEnabled: false,
forwardButtonEnabled: false,
loading: true,
scalesPageToFit: true,
};
inputText = '';
handleTextInputChange = (event) => {
var url = event.nativeEvent.text;
if (!/^[a-zA-Z-_]+:/.test(url)) {
url = 'http://' + url;
}
this.inputText = url;
};
render() {
this.inputText = this.state.url;
return (
<View style={[styles.container]}>
<View style={[styles.addressBarRow]}>
<TouchableOpacity
onPress={this.goBack}
style={this.state.backButtonEnabled ? styles.navButton : styles.disabledButton}>
<Text>
{'<'}
</Text>
</TouchableOpacity>
<TouchableOpacity
onPress={this.goForward}
style={this.state.forwardButtonEnabled ? styles.navButton : styles.disabledButton}>
<Text>
{'>'}
</Text>
</TouchableOpacity>
<TextInput
ref={TEXT_INPUT_REF}
autoCapitalize="none"
defaultValue={this.state.url}
onSubmitEditing={this.onSubmitEditing}
onChange={this.handleTextInputChange}
clearButtonMode="while-editing"
style={styles.addressBarTextInput}
/>
<TouchableOpacity onPress={this.pressGoButton}>
<View style={styles.goButton}>
<Text>
Go!
</Text>
</View>
</TouchableOpacity>
</View>
<WebView
ref={WEBVIEW_REF}
automaticallyAdjustContentInsets={false}
style={styles.webView}
source={{uri: this.state.url}}
javaScriptEnabled={true}
domStorageEnabled={true}
decelerationRate="normal"
onNavigationStateChange={this.onNavigationStateChange}
onShouldStartLoadWithRequest={this.onShouldStartLoadWithRequest}
startInLoadingState={true}
scalesPageToFit={this.state.scalesPageToFit}
/>
<View style={styles.statusBar}>
<Text style={styles.statusBarText}>{this.state.status}</Text>
</View>
</View>
);
}
goBack = () => {
this.refs[WEBVIEW_REF].goBack();
};
goForward = () => {
this.refs[WEBVIEW_REF].goForward();
};
reload = () => {
this.refs[WEBVIEW_REF].reload();
};
onShouldStartLoadWithRequest = (event) => {
// Implement any custom loading logic here, don't forget to return!
return true;
};
onNavigationStateChange = (navState) => {
this.setState({
backButtonEnabled: navState.canGoBack,
forwardButtonEnabled: navState.canGoForward,
url: navState.url,
status: navState.title,
loading: navState.loading,
scalesPageToFit: true
});
};
onSubmitEditing = (event) => {
this.pressGoButton();
};
pressGoButton = () => {
var url = this.inputText.toLowerCase();
if (url === this.state.url) {
this.reload();
} else {
this.setState({
url: url,
});
}
// dismiss keyboard
this.refs[TEXT_INPUT_REF].blur();
};
}
class Button extends React.Component {
_handlePress = () => {
if (this.props.enabled !== false && this.props.onPress) {
this.props.onPress();
}
};
render() {
return (
<TouchableWithoutFeedback onPress={this._handlePress}>
<View style={styles.button}>
<Text>{this.props.text}</Text>
</View>
</TouchableWithoutFeedback>
);
}
}
class ScaledWebView extends React.Component {
state = {
scalingEnabled: true,
};
render() {
return (
<View>
<WebView
style={{
backgroundColor: BGWASH,
height: 200,
}}
source={{uri: 'https://facebook.github.io/react/'}}
scalesPageToFit={this.state.scalingEnabled}
/>
<View style={styles.buttons}>
{ this.state.scalingEnabled ?
<Button
text="Scaling:ON"
enabled={true}
onPress={() => this.setState({scalingEnabled: false})}
/> :
<Button
text="Scaling:OFF"
enabled={true}
onPress={() => this.setState({scalingEnabled: true})}
/> }
</View>
</View>
);
}
}
class MessagingTest extends React.Component {
webview = null
state = {
messagesReceivedFromWebView: 0,
message: '',
}
onMessage = e => this.setState({
messagesReceivedFromWebView: this.state.messagesReceivedFromWebView + 1,
message: e.nativeEvent.data,
})
postMessage = () => {
if (this.webview) {
this.webview.postMessage('"Hello" from React Native!');
}
}
render(): ReactElement<any> {
const {messagesReceivedFromWebView, message} = this.state;
return (
<View style={[styles.container, { height: 200 }]}>
<View style={styles.container}>
<Text>Messages received from web view: {messagesReceivedFromWebView}</Text>
<Text>{message || '(No message)'}</Text>
<View style={styles.buttons}>
<Button text="Send Message to Web View" enabled onPress={this.postMessage} />
</View>
</View>
<View style={styles.container}>
<WebView
ref={webview => { this.webview = webview; }}
style={{
backgroundColor: BGWASH,
height: 100,
}}
source={require('./messagingtest.html')}
onMessage={this.onMessage}
/>
</View>
</View>
);
}
}
class InjectJS extends React.Component {
webview = null;
injectJS = () => {
const script = 'document.write("Injected JS ")'; // eslint-disable-line quotes
if (this.webview) {
this.webview.injectJavaScript(script);
}
}
render() {
return (
<View>
<WebView
ref={webview => { this.webview = webview; }}
style={{
backgroundColor: BGWASH,
height: 300,
}}
source={{uri: 'https://www.facebook.com'}}
scalesPageToFit={true}
/>
<View style={styles.buttons}>
<Button text="Inject JS" enabled onPress={this.injectJS} />
</View>
</View>
);
}
}
var styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: HEADER,
},
addressBarRow: {
flexDirection: 'row',
padding: 8,
},
webView: {
backgroundColor: BGWASH,
height: 350,
},
addressBarTextInput: {
backgroundColor: BGWASH,
borderColor: 'transparent',
borderRadius: 3,
borderWidth: 1,
height: 24,
paddingLeft: 10,
paddingTop: 3,
paddingBottom: 3,
flex: 1,
fontSize: 14,
},
navButton: {
width: 20,
padding: 3,
marginRight: 3,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: BGWASH,
borderColor: 'transparent',
borderRadius: 3,
},
disabledButton: {
width: 20,
padding: 3,
marginRight: 3,
alignItems: 'center',
justifyContent: 'center',
backgroundColor: DISABLED_WASH,
borderColor: 'transparent',
borderRadius: 3,
},
goButton: {
height: 24,
padding: 3,
marginLeft: 8,
alignItems: 'center',
backgroundColor: BGWASH,
borderColor: 'transparent',
borderRadius: 3,
alignSelf: 'stretch',
},
statusBar: {
flexDirection: 'row',
alignItems: 'center',
paddingLeft: 5,
height: 22,
},
statusBarText: {
color: 'white',
fontSize: 13,
},
spinner: {
width: 20,
marginRight: 6,
},
buttons: {
flexDirection: 'row',
height: 30,
backgroundColor: 'black',
alignItems: 'center',
justifyContent: 'space-between',
},
button: {
flex: 0.5,
width: 0,
margin: 5,
borderColor: 'gray',
borderWidth: 1,
backgroundColor: 'gray',
},
});
const HTML = `
<!DOCTYPE html>\n
<html>
<head>
<title>Hello Static World</title>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<meta name="viewport" content="width=320, user-scalable=no">
<style type="text/css">
body {
margin: 0;
padding: 0;
font: 62.5% arial, sans-serif;
background: #ccc;
}
h1 {
padding: 45px;
margin: 0;
text-align: center;
color: #33f;
}
</style>
</head>
<body>
<h1>Hello Static World</h1>
</body>
</html>
`;
exports.displayName = (undefined: ?string);
exports.title = '<WebView>';
exports.description = 'Base component to display web content';
exports.examples = [
{
title: 'Simple Browser',
render(): React.Element<any> { return <WebViewExample />; }
},
{
title: 'Scale Page to Fit',
render(): React.Element<any> { return <ScaledWebView/>; }
},
{
title: 'Bundled HTML',
render(): React.Element<any> {
return (
<WebView
style={{
backgroundColor: BGWASH,
height: 100,
}}
source={require('./helloworld.html')}
scalesPageToFit={true}
/>
);
}
},
{
title: 'Static HTML',
render(): React.Element<any> {
return (
<WebView
style={{
backgroundColor: BGWASH,
height: 100,
}}
source={{html: HTML}}
scalesPageToFit={true}
/>
);
}
},
{
title: 'POST Test',
render(): React.Element<any> {
return (
<WebView
style={{
backgroundColor: BGWASH,
height: 100,
}}
source={{
uri: 'http://www.posttestserver.com/post.php',
method: 'POST',
body: 'foo=bar&bar=foo'
}}
scalesPageToFit={false}
/>
);
}
},
{
title: 'Mesaging Test',
render(): ReactElement<any> { return <MessagingTest />; }
},
{
title: 'Inject JavaScript',
render(): React.Element<any> { return <InjectJS />; }
},
];