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Local datastore write methods do not return (e.g..: pin(), pinAll(), unpin(), unpinAll())

I'm building an android app using the Android Parse SDK, which gets all data from Parse at initialisation and stores it locally. Later, it will only update those entities (ParseObjects) which need so. I'm not getting any return from some Pin() operations, and similarly no callback when I use PinInBackground() and variants. Same happens with Unpin().
My code is something like the following. I have a list of ControlDate, a ParseObject which contains updated_at and updated_locally_at for each Parse data table. I use it to decide if I should query a given table (reducing number of queries). I iterate over this list when I perform a data update, in an IntentService, like this:
protected void onHandleIntent(Intent intent) {
for(ControlDate d : mUpdateQueue) { // mUpdateQueue is the list of ControlDate
if(d.entityNeedsUpdate()) { // returns true if updated_at > updated_locally_at
updateEntity(d);
}
}
private boolean updateEntity(ControlDate d) {
String tableName = d.getTableName();
Date lastLocalUpdate = d.getLastLocalUpdate();
ParseQuery<ParseObject> qParse = ParseQuery.getQuery(tableName);
qParse.whereGreaterThan("updated_at", lastLocalUpdate);
try {
// update the entities
List<ParseObject> entities = qParse.find();
ParseObject.pinAll(entities); // SOMETIMES GETS STUCK (no return)
// update the associated ControlDate
d.setLastLocalUpdate(new Date()); // updated_locally_at = now
d.pin(); // SOMETIMES GETS STUCK (no return)
}
catch(ParseException e) {
// error
}
}
}
Those operations SOMETIMES do not return. I'm trying to find a pattern but still no luck, apparently it started happening when I added pointer arrays to some of the entities. Thus, I think it may be due to the recursive nature of pin(). However it is strange that it sometimes also gets stuck with ParseObjects which do not reference any others - as it is the case with d.pin().
Things I've tried:
changing the for loop to a ListIterator (as I am changing the list of ControlDates, but I don't think this is necessary);
using the threaded variants (eg.: PinInBackground()) - no callback;
pinning each entity individually (in a loop, doing pin()) - a lot slower, still got stuck;
debugging - the thread just blocks here: http://i.imgur.com/oBDjpCw.png?1
I'm going crazy with this, help would be much appreciated!
PS.: I found this https://github.com/BoltsFramework/Bolts-Android/issues/48
Its an open issue on the bolts library, which is used in the Android SDK and may be causing this (maybe?). Anyway I cannot see how I could overcome my problem even though the cause for the pin() not returning could be an "unobserved exception" leading to a deadlock.

Android and Azure Mobile Services: Using invokeAPI to return recordset

I am trying something very simple. I have a custom API called "missingvehiclesfrominventoryjob" and it simply returns a record set from an standard SQL Query.
I can do this in my WinForms and Windows Phone app easily but I cannot figure out how to do this on the Android App.
Here is my code: (which DOES NOT COMPILE in Android Studio):
msClient.invokeApi("missingvehiclesfrominventoryjob", kd, new
ApiOperationCallback<List<InventoryProspects>>(){
#Override
public void onCompleted(List<InventoryProspects> missingVehicles, Exception e,
ServiceFilterResponse serviceFilterResponse){
for (InventoryProspects item : missingVehicles){
mAdapter.add(item);
}
}
});
The problem is the List in the parameters of the Callback. I am not sure how to indicate that the invoiceAPI call will return multiple rows from the database and I cannot find anywhere in the docs to explain how. Nor can I find an example ANYWHERE on the internet.
I am sure I am not the only on trying to do this.
Thanks in advance
Chuck Giddens

What i did to overcome this problem, is to call a different overload of invokeApi that returns a JsonElement, and then deserialise it into my objects like so:
mClient.invokeApi("MyCustomApi",null, "GET", null, new ApiJsonOperationCallback() {
#Override
public void onCompleted(JsonElement jsonElement, Exception e, ServiceFilterResponse serviceFilterResponse) {
GsonBuilder gsonb = new GsonBuilder();
Gson gson = gsonb.create();
JsonArray array = jsonElement.getAsJsonArray();
List<MyObject> myObjects = new ArrayList<MyObject>()>
for(int i = 0; i < array.size(); i++)
{
myObjects.add(gson.fromJson(array.get(i).getAsJsonObject().toString(), MyObject.class));
}
}
});

I haven't had a chance to test it yet (will try when I have time and edit answer as needed) but my thinking is that the Android SDK won't allow you to do what you're trying to do. The invokeApi methods expect a strongly typed class to be set as the response type (or you can use the raw JSON methods). In this case, you're trying to say you want a list of items back, but I don't think that will work. I think you'll instead need to create a new class (i.e. missingvehiclesfrominventoryjobResponse) which contains a property that is of type List< InventoryProspects>. Note that you'll need to change your method call to actually match one of the available options for invokeApi which I don't believe it's doing right now. You can read more about the different formats of the method here: http://blogs.msdn.com/b/carlosfigueira/archive/2013/06/19/custom-api-in-azure-mobile-services-client-sdks.aspx
Alternatively, you can use the table methods against a table endpoint where the read expects a collection of results back.

Have you tried to remote debug your API call from the app.[http://blogs.msdn.com/b/azuremobile/archive/2014/03/14/debugging-net-backend-in-visual-studio.aspx]. Your app will timed out in doing that but you can see line by line execution of your controller action if it returns the correct result set. If there is no problem with it then the problem should be in parsing result set.
What is the exception you are getting in callback? And have you tried using other method parameters such as passing with different HTTP methods? Use this as a reference as well. http://azure.microsoft.com/en-us/documentation/articles/mobile-services-android-get-started/
Please paste your exception or either controller action, and the object structure of the data transfer object of the result set.

kSOAP2 double ID exception

I am attempting to use kSOAP 2 in my android application, and when I try to perform a particular webservice request, I end up getting thrown a "double ID" exception. I was able to find where this gets thrown in the kSOAP source code, it is in the SoapSerializationEnvelope class method public Object read() Here is an excerpt from that code showing the exception being thrown:
if (id != null) {
Object hlp = idMap.get(id);
if (hlp instanceof FwdRef) {
FwdRef f = (FwdRef) hlp;
do {
if (f.obj instanceof KvmSerializable)
((KvmSerializable) f.obj).setProperty(f.index, obj);
else
((Vector) f.obj).setElementAt(obj, f.index);
f = f.next;
} while (f != null);
} else if (hlp != null)
throw new RuntimeException("double ID");
idMap.put(id, obj);
}
I'm not at all sure what this exception is about, or how I can fix it. Anyone know what the deal with this exception is?
Thanks
Edit:
It should be noted that I am also using a SOAP webservice connection method in the iOS version of this application, and the same exact request does not have any problems.
New information:
Upon closer inspection, the problem seems to be resulting from the xml response I am getting containing a <diffgr:before> element, which has tables with the same ID as above. I think this is the cause of the problem, the other requests I have performed up to this point do not have that element in them, and do not have the exception. So to add to the question: can I stop the webservice from sending this block in its response, or get kSOAP to ignore it?

I was able to resolve this by removing the diffgr:before element the webservice was sending. I did that thanks to this post

well, I had the same problem too, but I had no diffgr:before in the xml response (And I can't change the webservice at all). Anyway, the problem was due to some empty values in the response. Using XOM
I managed to remove all empty elements and the it worked like charm. This is done by converting the response to string, loading it into nu.xom.Document element, remove the empty elements from the document and revert it back to InputStream for parsing with ksoap2

Android - try/catch question

i have a try/catch in a function that returns a value. if all goes well the return statement in the try block works fine. but what am i supposed to do if theres an exception? what do i return in the catch and finally blocks? the return statement has to be there or the code doesnt compile.
edit: in 1 function i connect to a URL, read a file, and return a string. in another function i open an image from the internet and return a bitmap. so in both of these cases, what am i supposed to have in the return statement at the catch and finally blocks?

One of the following:
Return a special value that indicates an error to the calling code.
Return a default value (depending on your context, there may not be a good one).
Don't catch the exception, instead add a throws to the header.
Catch the exception, do the cleanup, and rethrow the exception.
In general, there's no escaping the fact that the function can error out. The calling code must either be notified of that, or the function must effectively swallow an error and pretend nothing bad happened; that involves returning something. The specifics depend on your context...

The value you return should be able to represent an error, for example, null should mean the function didn't work. So, in the catch block, the function would return null, for example. In the finally block, you should free any resource you used (for example, close any files you opened, etc).
You put those things in the finally block because it's guaranteed that it will be ran sometime, even if the code in your catch block throws an unhandled exception or anything. And it will also run if the function worked just as wanted.

Use return null; this statement outside your try/catch block. If the things work, your try block will execute and will return , if it fails because of exception, it will be caught and you will see error.

Android - Testing a simple Activity method

i'm writing you today because i have a real and concrete question about how testing an activity method. Let me explain the situation.
I have an activity (A) which use a method save(param) from a service (S). This method throws a specific exception if the parameter is invalid.
Unit tests are written for this part, and now, i would like to test the Activity part :
In my Activty, i use the following code to call the save() method
public void OnSaveClicked()
{
try{
if ( S.save(my_object) > 0 ) // Object Saved
{
ShowToast(this, "Your object has been saved successfully !");
}
else { // Error occured with the database
ShowToast(this, "An error occured with the database");
}
catch (MyException ex)
{
ShowToast(this, "The object you are trying to save is not valid... Please check information you entered");
}
}
The test that i'm trying to write has to check if the save() method raised the exception or not. To do that, i simulate a click on the UI Button, but, i don't really know what do i have to check. I read that's not possible to write an assert on a toast message. I'm currently thinking about using a dialog but i am not sure that the way i'm thinking is the right one. Is it normal to test that or not ?
Would you give me your feedback about that, and discuss about the right way to test activity ?
Thanks,
t00f

You might want to look at Robolectric. They have support for assertions like this http://groups.google.com/group/robolectric/browse_thread/thread/87952e620ce1bb37?pli=1
Thanks,
Ian