I'm having trouble getting the Webview on ReactNative to execute the injected JavaScript on a physical Android device. I've scoured the web as far as I could over the past 2 days and still haven't found a solution. Results for testing are as follows:
My Webview is defined as follows:
<WebView
style={styles.webView}
source={{
html: html,
baseUrl: 'web/'
}}
injectedJavaScript={'render(' + JSON.stringify(this.state.data) + ');'}
javaScriptEnabledAndroid={true}
scrollEnabled={false}
bounces={false}
renderLoading={() => <LoadingIndicator />}
/>
I've tried specifying javaScriptEnabled
as well, to no avail. I also tried smaller scripts to just colour elements on the page or post a message back to the app using window.postMessage
, but nothing happens. I need to inject the data to the HTML, which will render graphs for me based on the supplied data. My last resort is to manually construct the HTML with the data appended as part of the markup being supplied to the Webview, but I'd really like to keep it simple and just get it to work the way it should.
I'm using the latest version of ReactNative (0.41) and the phones are running Android 6+.
I just discovered that the Android WebView appears to inject any JS as a single line, even if it includes line breaks. That means that missing semicolons can definitely cause issues, or, in my case, comments delimited by //
. Using /*
and */
for comments got my injected JavaScript working again.
Well, after leaving this question open for some time and finding a (not so elegant) solution to the problem, I decided I'd share what I ended up doing:
const html = '<html>...<script>...[INJECTEDSCRIPT]</script></html>';
componentDidMount()
event of the React component's lifecycle and set a state variable for it using this.setState({ data: retrievedData });
injectedJavaScript
property to work the way I want it to (as stated in the question), I resorted to replacing the [INJECTEDSCRIPT]
value in the HTML constant with the serialized data.Not the most elegant solution, I know, but it's the only one I could get working reliably across a multitude of devices and emulator configurations. Sample, edited for brevity, as below:
const html = `
<!DOCTYPE html>
<html>
<head>...</head>
<body>...</body>
<script>
var render = function (data) {
...
};
[INJECTEDSCRIPT]
</script>
</html>`;
export class GraphComponent extends Component {
constructor(props) {
super(props);
this.state = {};
}
componentDidMount = () => {
SERVICE.getData().done((data) => {
this.setState({ data: data });
});
}
render = () => {
if (!this.state.data)
return <LoadingIndicator />;
let serializedData = JSON.stringify(this.state.data);
return
<WebView
style={styles.webView}
source={{
html: html.replace('[INJECTEDSCRIPT]', 'render(' + serializedData + ');'),
baseUrl: 'web/'
}}
scrollEnabled={false}
bounces={false}
renderLoading={() => <LoadingIndicator />}
/>;
}
}
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