10. Create a class file for edit_product.xml and name it as EditProductActivity.java and fill it with following code. In the following code
-> First product id (pid) is read from the intent which is sent from listview.
-> A request is made to get_product_details.php and after getting product details in json format, I parsed the json and displayed in EditText.
-> After displaying product data in the form if user clicks on Save Changes Button, another HTTP request is made to update_product.php to store updated product data.
-> If the user selected Delete Product Button, HTTP request is made to delete_product.php and product is deleted from mysql database, and listview is refreshed with new product list.
-> After displaying product data in the form if user clicks on Save Changes Button, another HTTP request is made to update_product.php to store updated product data.
-> If the user selected Delete Product Button, HTTP request is made to delete_product.php and product is deleted from mysql database, and listview is refreshed with new product list.
package com.example.androidhive;import java.util.ArrayList;import java.util.List;import org.apache.http.NameValuePair;import org.apache.http.message.BasicNameValuePair;import org.json.JSONArray;import org.json.JSONException;import org.json.JSONObject;import android.app.Activity;import android.app.ProgressDialog;import android.content.Intent;import android.os.AsyncTask;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.EditText;public class EditProductActivity extends Activity { EditText txtName; EditText txtPrice; EditText txtDesc; EditText txtCreatedAt; Button btnSave; Button btnDelete; String pid; // Progress Dialog private ProgressDialog pDialog; // JSON parser class JSONParser jsonParser = new JSONParser(); // single product url private static final String url_product_detials = "https://api.androidhive.info/android_connect/get_product_details.php"; // url to update product private static final String url_update_product = "https://api.androidhive.info/android_connect/update_product.php"; // url to delete product private static final String url_delete_product = "https://api.androidhive.info/android_connect/delete_product.php"; // JSON Node names private static final String TAG_SUCCESS = "success"; private static final String TAG_PRODUCT = "product"; private static final String TAG_PID = "pid"; private static final String TAG_NAME = "name"; private static final String TAG_PRICE = "price"; private static final String TAG_DESCRIPTION = "description"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.edit_product); // save button btnSave = (Button) findViewById(R.id.btnSave); btnDelete = (Button) findViewById(R.id.btnDelete); // getting product details from intent Intent i = getIntent(); // getting product id (pid) from intent pid = i.getStringExtra(TAG_PID); // Getting complete product details in background thread new GetProductDetails().execute(); // save button click event btnSave.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { // starting background task to update product new SaveProductDetails().execute(); } }); // Delete button click event btnDelete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { // deleting product in background thread new DeleteProduct().execute(); } }); } /** * Background Async Task to Get complete product details * */ class GetProductDetails extends AsyncTask<String, String, String> { /** * Before starting background thread Show Progress Dialog * */ @Override protected void onPreExecute() { super.onPreExecute(); pDialog = new ProgressDialog(EditProductActivity.this); pDialog.setMessage("Loading product details. Please wait..."); pDialog.setIndeterminate(false); pDialog.setCancelable(true); pDialog.show(); } /** * Getting product details in background thread * */ protected String doInBackground(String... params) { // updating UI from Background Thread runOnUiThread(new Runnable() { public void run() { // Check for success tag int success; try { // Building Parameters List<NameValuePair> params = new ArrayList<NameValuePair>(); params.add(new BasicNameValuePair("pid", pid)); // getting product details by making HTTP request // Note that product details url will use GET request JSONObject json = jsonParser.makeHttpRequest( url_product_detials, "GET", params); // check your log for json response Log.d("Single Product Details", json.toString()); // json success tag success = json.getInt(TAG_SUCCESS); if (success == 1) { // successfully received product details JSONArray productObj = json .getJSONArray(TAG_PRODUCT); // JSON Array // get first product object from JSON Array JSONObject product = productObj.getJSONObject(0); // product with this pid found // Edit Text txtName = (EditText) findViewById(R.id.inputName); txtPrice = (EditText) findViewById(R.id.inputPrice); txtDesc = (EditText) findViewById(R.id.inputDesc); // display product data in EditText txtName.setText(product.getString(TAG_NAME)); txtPrice.setText(product.getString(TAG_PRICE)); txtDesc.setText(product.getString(TAG_DESCRIPTION)); }else{ // product with pid not found } } catch (JSONException e) { e.printStackTrace(); } } }); return null; } /** * After completing background task Dismiss the progress dialog * **/ protected void onPostExecute(String file_url) { // dismiss the dialog once got all details pDialog.dismiss(); } } /** * Background Async Task to Save product Details * */ class SaveProductDetails extends AsyncTask<String, String, String> { /** * Before starting background thread Show Progress Dialog * */ @Override protected void onPreExecute() { super.onPreExecute(); pDialog = new ProgressDialog(EditProductActivity.this); pDialog.setMessage("Saving product ..."); pDialog.setIndeterminate(false); pDialog.setCancelable(true); pDialog.show(); } /** * Saving product * */ protected String doInBackground(String... args) { // getting updated data from EditTexts String name = txtName.getText().toString(); String price = txtPrice.getText().toString(); String description = txtDesc.getText().toString(); // Building Parameters List<NameValuePair> params = new ArrayList<NameValuePair>(); params.add(new BasicNameValuePair(TAG_PID, pid)); params.add(new BasicNameValuePair(TAG_NAME, name)); params.add(new BasicNameValuePair(TAG_PRICE, price)); params.add(new BasicNameValuePair(TAG_DESCRIPTION, description)); // sending modified data through http request // Notice that update product url accepts POST method JSONObject json = jsonParser.makeHttpRequest(url_update_product, "POST", params); // check json success tag try { int success = json.getInt(TAG_SUCCESS); if (success == 1) { // successfully updated Intent i = getIntent(); // send result code 100 to notify about product update setResult(100, i); finish(); } else { // failed to update product } } catch (JSONException e) { e.printStackTrace(); } return null; } /** * After completing background task Dismiss the progress dialog * **/ protected void onPostExecute(String file_url) { // dismiss the dialog once product uupdated pDialog.dismiss(); } } /***************************************************************** * Background Async Task to Delete Product * */ class DeleteProduct extends AsyncTask<String, String, String> { /** * Before starting background thread Show Progress Dialog * */ @Override protected void onPreExecute() { super.onPreExecute(); pDialog = new ProgressDialog(EditProductActivity.this); pDialog.setMessage("Deleting Product..."); pDialog.setIndeterminate(false); pDialog.setCancelable(true); pDialog.show(); } /** * Deleting product * */ protected String doInBackground(String... args) { // Check for success tag int success; try { // Building Parameters List<NameValuePair> params = new ArrayList<NameValuePair>(); params.add(new BasicNameValuePair("pid", pid)); // getting product details by making HTTP request JSONObject json = jsonParser.makeHttpRequest( url_delete_product, "POST", params); // check your log for json response Log.d("Delete Product", json.toString()); // json success tag success = json.getInt(TAG_SUCCESS); if (success == 1) { // product successfully deleted // notify previous activity by sending code 100 Intent i = getIntent(); // send result code 100 to notify about product deletion setResult(100, i); finish(); } } catch (JSONException e) { e.printStackTrace(); } return null; } /** * After completing background task Dismiss the progress dialog * **/ protected void onPostExecute(String file_url) { // dismiss the dialog once product deleted pDialog.dismiss(); } }} |
JSON Parser Class
I used a JSON Parser class to get JSON from URL. This class supports two http request methods GET and POST to get json from url.
package com.example.androidhive;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.UnsupportedEncodingException;import java.util.List;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.utils.URLEncodedUtils;import org.apache.http.impl.client.DefaultHttpClient;import org.json.JSONException;import org.json.JSONObject;import android.util.Log;public class JSONParser { static InputStream is = null; static JSONObject jObj = null; static String json = ""; // constructor public JSONParser() { } // function get json from url // by making HTTP POST or GET mehtod public JSONObject makeHttpRequest(String url, String method, List<NameValuePair> params) { // Making HTTP request try { // check for request method if(method == "POST"){ // request method is POST // defaultHttpClient DefaultHttpClient httpClient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(url); httpPost.setEntity(new UrlEncodedFormEntity(params)); HttpResponse httpResponse = httpClient.execute(httpPost); HttpEntity httpEntity = httpResponse.getEntity(); is = httpEntity.getContent(); }else if(method == "GET"){ // request method is GET DefaultHttpClient httpClient = new DefaultHttpClient(); String paramString = URLEncodedUtils.format(params, "utf-8"); url += "?" + paramString; HttpGet httpGet = new HttpGet(url); HttpResponse httpResponse = httpClient.execute(httpGet); HttpEntity httpEntity = httpResponse.getEntity(); is = httpEntity.getContent(); } } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } try { BufferedReader reader = new BufferedReader(new InputStreamReader( is, "iso-8859-1"), 8); StringBuilder sb = new StringBuilder(); String line = null; while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } is.close(); json = sb.toString(); } catch (Exception e) { Log.e("Buffer Error", "Error converting result " + e.toString()); } // try parse the string to a JSON object try { jObj = new JSONObject(json); } catch (JSONException e) { Log.e("JSON Parser", "Error parsing data " + e.toString()); } // return JSON String return jObj; }} |
Run your project and test the application. You might get lot of errors. Always use Log Cat to debug your application, and if you couldn’t solve your errors please do comment here.
