Get value from input field in webview to react native-CodePudding

I want to get the user's input from a inputfield in webview and then use it in react native to change the value of "answer".

Within webview I created an inputfield with the id="data_1". I get the input data through "oninput" and save it in "answer". But I fail to "answer" into react native by using window.ReactNativeWebView.postMessage(answer);

Any ideas?

This is my code:

import { Button, StyleSheet, Text, View, TouchableOpacity } from "react-native";
import { WebView } from "react-native-webview";


class MySweetComponent extends Component {

  render() {
 const run = `
      document.body.style.backgroundColor = 'blue';
      true;`

    let answer = "I want to change after user Input"

 setTimeout(() => {
   this.webref.injectJavaScript(run); 
 }, 1000);

  return (
    <View style={{ width: 350, height: 200 }}>
      <WebView
        scalesPageToFit={false}
        ref={(r) => (this.webref = r)}
        androidHardwareAccelerationDisabled={true} // To prevent crash when opening screen
        onMessage={(event) => {
          event.nativeEvent.data;
        }}
        source={{
          html: `

 <html>

      </pre>
    <input type="text" placeholder="Enter text" id="data_1" oninput="getValue()">
    <script>
    
    function getValue() {
    let answer = document.getElementById("data_1").value;
}
     window.ReactNativeWebView.postMessage(answer);
      true;
    </script>
    </body>
  </html>
  `,
        }}
      />
      <Text>{answer}</Text>
    </View>
  );
      }
}


export default MySweetComponent;

CodePudding user response：

I think you have an html error with the pre tag

</pre>

just remove that and put your whole <script/> before the html to be able to call it then.

And might you just want the value once the user ends writing. I would use onblur instead of oninput to avoid sending message for each key pressed, but both ways should work

CodePudding user response：

ok, I think we many things, lets do it step by step

import { useState } from 'react';
import { Button, StyleSheet, Text, View, TouchableOpacity } from "react-native";
import { WebView } from "react-native-webview";

const html = `
  <html>
  <head></head>
  <body>   
   <input id="myId" placeholder="Enter text" oninput="getValue()">
   <script>
    window.id = setInterval(() => {
      if (window.ReactNativeWebView) {
        document.body.style.backgroundColor = 'green'; 
        clearInterval(window.id);
      }
    }, 1000);
     function getValue() {
       let answer = document.getElementById("myId").value;
       window.ReactNativeWebView.postMessage(answer);              
     };
   </script>  
  </body>
  </html>
`;

const MySweetComponent = () => {
  const [answer, setAnswer] = useState("I want to change after user Input");
  return (
    <View style={{ width: 350, height: 200 }}>
      <WebView        
        onMessage={(event) => {
          console.log("EVENT-DATA:", event);
          setAnswer(event.nativeEvent.data);
        }}
        source={{html}} 
      />
      <Text>{answer}</Text>
    </View>
  );    
};


export default MySweetComponent;