Question

What I’m trying to do:

1. user fills out a form data, clicks submit.
2. user presented with a loading screen. (HTML element).
3. Application makes asynchronous call, PhoneGap plugin, which saves this data in db. That’s where the problem is, because the call is synchronous instead.
4. When html app receives a callback, I hide loading screen.

Because of synchronous call that’s what I got:

1. user fills out a form, submits
2. HTML app freezes, data is being saved to a database.
3. loading screen appears
4. callback is called, a few milliseconds after.

Here’s some demo (trimmed) code:

Java:

public class SomePlugin extends Plugin
...
public PluginResult execute(String action, JSONArray data, String callbackId) 
{
    PluginResult result = null;
    //
    // save data in the background...
    //
    Log.d("TAG", "Some Message...");

    result = new PluginResult(Status.OK, "");
    // or 
    // result = new PluginResult(Status.ERROR);

    return result;
}
...
public boolean isSynch(String action) {
     return false; // always do async...
}

JavaScript:

$('#loading-screen').show();

var successCallback = function() {
    console.log('Success Callback');
    $('#loading-screen').hide();
};
var failureCallback = function() {
    console.log('Failed Callback');
    $('#loading-screen').hide();
};

PhoneGap.exec(successCallback, failureCallback, 'PluginName', 'actionName', data);

From PhoneGap source:

* Execute a PhoneGap command.  It is up to the native side whether this action is synch or async.
* The native side can return:
*      Synchronous: PluginResult object as a JSON string
*      Asynchrounous: Empty string ""
* If async, the native side will PhoneGap.callbackSuccess or PhoneGap.callbackError,
* depending upon the result of the action.

So I thought maybe this line is incorrect in that case:

new PluginResult(Status.OK, "");

Note: If wrap (JavaScript) PhoneGap.exec call in setTimeout (with a delay of 1 sec for example), loading screen will work “properly” (it’s still frozen but user have an instant feedback), but that’s obviously not a solution.

I think I just not seeing something obvious here, just one parameter or something somewhere.

Thanks.

Answer 1

I think its perfect for an AsyncTask
just process you dbStorage in doInBackground and handle finishing in onPostExcecute().
You are free to update status in onProgressUpdate