Adding a Custom Plug-in to the Android Hybrid Web Container

<plugin name="DirectoryListPlugin" value="com.sybase.hwc.DirectoryListPlugin" /> 

The plug-in used in this example does not include images, but they are allowed in plug-ins. Images for plug-ins are usually stored in res\drawable.

This example PhoneGap plug-in lists all files on the SDCard of the device.

/**
 * Example of Android PhoneGap Plugin
 */
package com.sybase.hwc;

import java.io.File;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

import org.apache.cordova.api.Plugin;
import org.apache.cordova.api.PluginResult;
import org.apache.cordova.api.PluginResult.Status;
	
/**
 * PhoneGap plugin which can be involved in following manner from javascript
 * <p>
 * result example - {"filename":"/sdcard","isdir":true,"children":[{"filename":"a.txt","isdir":false},{..}]}
 * </p>
 * <pre>
 * {@code
 * successCallback = function(result){
 *     //result is a json
 *  
 * }
 * failureCallback = function(error){
 *     //error is error message
 * }
 *	
 * window.plugins.DirectoryListing.list("/sdcard",
 *			                            successCallback
 *			                            failureCallback);
 *		                               
 * }
 * </pre>
 * @author Rohit Ghatol
 * 
 */
public class DirectoryListPlugin extends Plugin {

	/** List Action */
	public static final String ACTION="list";
	
	/*
	 * (non-Javadoc)
	 * 
	 * @see com.phonegap.api.Plugin#execute(java.lang.String,
	 * org.json.JSONArray, java.lang.String)
	 */
	@Override
	public PluginResult execute(String action, JSONArray data, String callbackId) {
		Log.d("DirectoryListPlugin", "Plugin Called");
		PluginResult result = null;
		if (ACTION.equals(action)) {
			try {

				String fileName = data.getString(0);
				JSONObject fileInfo = getDirectoryListing(new File(fileName));
				Log
						.d("DirectoryListPlugin", "Returning "
								+ fileInfo.toString());
				result = new PluginResult(Status.OK, fileInfo);
			} catch (JSONException jsonEx) {
				Log.d("DirectoryListPlugin", "Got JSON Exception "
						+ jsonEx.getMessage());
				result = new PluginResult(Status.JSON_EXCEPTION);
			}
		} else {
			result = new PluginResult(Status.INVALID_ACTION);
			Log.d("DirectoryListPlugin", "Invalid action : "+action+" passed");
		}
		return result;
	}

	/**
	 * Gets the Directory listing for file, in JSON format
	 * @param file The file for which we want to do directory listing
	 * @return JSONObject representation of directory list. e.g {"filename":"/sdcard","isdir":true,"children":[{"filename":"a.txt","isdir":false},{..}]}
	 * @throws JSONException
	 */
	private JSONObject getDirectoryListing(File file)
			throws JSONException {
		JSONObject fileInfo = new JSONObject();
		fileInfo.put("filename", file.getName());
		fileInfo.put("isdir", file.isDirectory());

		if (file.isDirectory()) {
			JSONArray children = new JSONArray();
			fileInfo.put("children", children);
			if (null != file.listFiles()) {
				for (File child : file.listFiles()) {
					children.put(getDirectoryListing(child));
				}
			}
		}

		return fileInfo;
	}
}

These are all the changes needed for the Hybrid Web Container; you can now build it and install it on the device. What the plug-in actually does is implemented in the Java file in the execute function.