Phonegap Cordova 2.2插件开发，无法在Java和JavaScript之间进行通信

Question

I have been trying to get this to work for past few hours now. I have cordova 2.2.

I created a new package called com.tester.newvideouri .

I have a class called newVideoUri in this package with the following content

package com.tester.newvideouri;

import org.apache.cordova.api.CallbackContext;
import org.apache.cordova.api.CordovaPlugin;
import org.json.JSONArray;
import org.json.JSONException;

/**
 * This class echoes a string called from JavaScript.
 */
public class newVideoUri extends CordovaPlugin {
    @Override
    public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
        if (action.equals("echo")) {
            String message = args.getString(0); 
            this.echo(message, callbackContext);
            return true;
        }
        return false;
    }

    private void echo(String message, CallbackContext callbackContext) {
        System.out.println("success here and display it");
        if (message != null && message.length() > 0) { 
            callbackContext.success(message);
        } else {
            callbackContext.error("Expected one non-empty string argument.");
        }
    }
}

In my config.xml I added following line:

    <plugin name="Echo" value="com.tester.newvideouri.newVideoUri" />

in my javascript file I have following:

    function onLoad() {
        document.addEventListener("deviceready", onDeviceReady, false);
    }
    window.onDeviceReady = function() {         
        window.echo = function(str, callback) {
            alert('Started');
            cordova.exec(callback, function(err) {
                callback('Nothing to echo.');
            }, "Echo", "echo", [ str ]);
            alert('The END');
        };          
        window.echo("echome", function(echoValue) {
            alert(echoValue == "echome"); // should alert true.
        });
    }

Nothing happens when I run the code. Can anyone please tell me what am I doing wrong?

Answer 1

write your "echome" code into a function like this:

function echome(){
    window.echo("echome", function(echoValue){
    alert(echoValue == "echome");
    });
}

and call this function in html code like this:

<a href="javascript:echome();">Click here</a>

try to run it. It was working for me. :)

Answer 2

Code is correct per this example: http://docs.phonegap.com/en/2.6.0/guide_plugin-development_android_index.md.html#Developing%20a%20Plugin%20on%20Android

Likely your issue is that cordova is failing to "hook" up. You did added cordova.android.js to your web page right?

If so make sure the device ready is actually being called:

window.onDeviceReady = function() {
  alert('ready to work'); 
   // if you do not see this alert nothing in cordova will work as 
   // it means communication was not started

}

Answer 3

You need to enter this in your javascript file:

cordova.define("cordova/plugin/sampleplugin", function(require, exports, module) {
  var exec = require('cordova/exec');
  var SamplePlugin = function() {};

  SamplePlugin.prototype.authenticate = function(loginId,plainTextPassword,successCallback,failureCallback) {
        return exec(successCallback, failureCallback, 'SamplePlugin', 'authenticate', [loginId,plainTextPassword]);

  }
        var sampleplugin = new SamplePlugin();
        module.exports = sampleplugin;
});

Here SamplePlugin is the name of my plugin.

Also in your html file, write this code:

var sampleplugin = cordova.require("cordova/plugin/sampleplugin");
           function  callrestfulweb()
{
               var loginId= document.getElementById("loginId").value;
               var plainTextPassword = document.getElementById("plainTextPassword").value;
               sampleplugin.authenticate(loginId,plainTextPassword,function(){alert("login successful");},function(){alert("Invalid username or password ");})
       }

I hope you can understand through this example.

Answer 4

you need to enter this in your javascript file:

cordova.define("cordova/plugin/sampleplugin", function(require, exports, module) {
  var exec = require('cordova/exec');
  var SamplePlugin = function() {};

  SamplePlugin.prototype.authenticate = function(loginId,plainTextPassword,successCallback,failureCallback) {
        return exec(successCallback, failureCallback, 'SamplePlugin', 'authenticate', [loginId,plainTextPassword]);

  }
        var sampleplugin = new SamplePlugin();
        module.exports = sampleplugin;
});

Here SamplePlugin is the name of my

Also in your html file,write this code

var sampleplugin = cordova.require("cordova/plugin/sampleplugin");
           function  callrestfulweb()
{
               var loginId= document.getElementById("loginId").value;
               var plainTextPassword = document.getElementById("plainTextPassword").value;
               sampleplugin.authenticate(loginId,plainTextPassword,function(){alert("login successful");},function(){alert("Invalid username or password ");})
       }

I hope you can understand through this example.