how to use spinners with xml file?

[Karen Wilson]

I have an app that displays contents of an xml file that is stored on a server. The xml file contains a list of events and these events have categories. I want to be able to select which category I want then only display the events for that category. So I created a new xml with a spinner but I have no idea what I need to change in the code so for example if I select the film category only the film events are displayed. I know i will also need to change the events xml file.

here is some of the xml file:

<packages>
<category>
<name>City of Churches Exhibition</name>
<date>March 20, 2014 - 19:00</date>
<distance>0</distance>
</category>
<category>
<name>Limerick Film Commission</name>
<date>January 1, 2014 - 12:17</date>
<distance>0</distance>
</category>
</packages>

and here is main java class that displays the xml file from the server:

public class TravelPackagesActivity extends Activity {
/** Called when the activity is first created. */
static String LIST_URL = "http://server/packages.xml"; //xampp on mmserver
ArrayList<HashMap<String, String>> packageList;
Handler mHandler;
PackageDownloadTask mTask;
ProgressDialog mProgress;
public Object onRetainNonConfigurationInstance() {
Log.v("XML", "Saving data");
return packageList;
}
private void startBackgroundTask(){
mProgress = ProgressDialog.show(this, "Loading category packages", "Please wait...", true);
mProgress.setCancelable(true);
mProgress.setOnCancelListener(new OnCancelListener() {
public void onCancel(DialogInterface arg0) {
TravelPackagesActivity.this.finish();
}
});
mProgress.show();
mTask = new PackageDownloadTask();
mTask.execute();
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//loadTourPackages();
//displayTourPackages();
mHandler = new Handler() {
public void handleMessage(Message msg){
mProgress.dismiss();
if (msg.what == 1) {
new AlertDialog.Builder(TravelPackagesActivity.this)
.setTitle("Error")
.setPositiveButton(android.R.string.ok, null)
.setMessage("Failed to download packages")
.show();
} else {
displayTourPackages();
}
}
};
packageList = (ArrayList<HashMap<String,String>>) getLastNonConfigurationInstance();
if (packageList == null) {
startBackgroundTask();
} else {
displayTourPackages();
}
}
private void displayTourPackages() {
String from[] = { "name", "date", "distance" };
int to[] = { R.id.PackageTitle, R.id.PackageDate,
R.id.PackageDistance };
SimpleAdapter a = new SimpleAdapter(this, packageList,
R.layout.package_list_item, from, to);
ListView l = (ListView) findViewById(R.id.PackageListView);
l.setAdapter(a);
}
public class PackageDownloadTask extends AsyncTask<Void, Void, Void> {
boolean bFailed = false;
private void loadTourPackages() {
try {
HttpParams params = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(params, 10000);
HttpConnectionParams.setSoTimeout(params, 10000);
DefaultHttpClient client = new DefaultHttpClient(params);
HttpGet get = new HttpGet(LIST_URL);
HttpResponse res = client.execute(get);
int code = res.getStatusLine().getStatusCode();
if (code != 200) {
throw new Exception("Invalid status code: " + code);
}
Log.v("XML", "Successfully fetched XML file");
InputStream is = res.getEntity().getContent();
packageList = new ArrayList<HashMap<String, String>>();
XmlPullParserFactory parserCreator = XmlPullParserFactory
.newInstance();
XmlPullParser parser = parserCreator.newPullParser();
parser.setInput(is, null);
int event;
String name = null;
String distance = null;
String date= null;
String tag = null;
while ((event = parser.next()) != XmlPullParser.END_DOCUMENT) {
if (isCancelled()) {
Log.v("XML", "Cancelling XML processing");
break;
}
if (event == XmlPullParser.START_TAG) {
tag = parser.getName();
if ("category".equals(tag)) {
name = date= distance = ""; // Clear values
}
} else if (event == XmlPullParser.TEXT) {
if ("distance".equals(tag)) {
distance = parser.getText();
} else if ("name".equals(tag)) {
name = parser.getText();
} else if ("date".equals(tag)) {
date= parser.getText();
}
} else if (event == XmlPullParser.END_TAG) {
if ("category".equals(parser.getName())) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("name", name);
map.put("date", date);
map.put("distance", distance);
packageList.add(map);
Log.v("XML", "Loaded package: " + name);
Thread.sleep(1000);
}
tag = null; // Reset tag name
}
}
} catch (Exception e) {
Log.v("XML", "Error fetching packages.xml", e);
bFailed = true;
}
}
@Override
protected Void doInBackground(Void... params) {
Log.v("XML", "Loading data from AsyncTask");
loadTourPackages();
if(!isCancelled()) {
mHandler.sendEmptyMessage(bFailed ? 1 : 0);
}
return null;
}
}
protected void OnDestroy() {
if (mTask != null)
mTask.cancel(false);
super.onDestroy();
}
}

[Ulf Dittmer]

After the download and XML parsing, a "loadTourPackages" method is called - I think that should be "displayTourPackages", so that the display gets updated, no? You may need to invalidate the layout so that the UI gets updated.

[Irina Goble]

You could use SQLite with a SimpleCursorAdapter or write your own Adapter that will filter by chosen category or, maybe, ask the server for events of that particular category only. Is the question about how to filter events?

You are already using an AsyncTask, there is no need for a Handler. AsyncTask.onPostExecute() can do whatever the Handler must do.