How to print error message of why image failed to load? - gwt

Can we get any error information from an image load failure? I have the following:
Image image = new Image(imagePath);
image.addErrorHandler(new ErrorHandler() {
Override
public void onError(ErrorEvent event) {
// what can we print here from 'event'?
}
});
I have an image that fails to load once in awhile, and I just tried letting the event.toString() method print itself, but I just get something like:
println("Error!: " + event);
// "Error: An event type"
so I'm not sure why the image fails to load,
Thank you

Currently you can't know what caused the error, but you can know what type of error caused it and it gives fairly a good idea on what might have gone wrong
event.getAssociatedType();
OR
event.getType();

Related

Why 'link' variable gets changed to null even after i assign it a value

private fun shareOperation(file: File) {
val uri = Uri.fromFile(file)
val storage = FirebaseStorage.getInstance()
val pdfRef = storage.reference.child("pdf/${uri.lastPathSegment}")
pdfRef.putFile(uri).addOnFailureListener { e ->
Log.e(TAG, "Couldn't share " + e.message)
}.addOnCompleteListener{
it.addOnCompleteListener {
pdfRef.downloadUrl.addOnSuccessListener { e ->
run {
link = e.toString()
Log.i(TAG,link!!) // Here i get the link to file in firebase storage
}
}
}
}
// Here link gets null
}
i was expecting somehow i can get the link to the file and can use it for sharing intent
You are performing an asynchronous call to upload the file, that is correct since any UI blocking action must be performed in background. The variable link will be null until the run code is executed in the background thread.
You need to code inside the run block whatever you want to happen when the link is available.
BTW looks weird what you are doing with the nested addOnCompleteListener, there should be an easier way to code that. You should probably spend time learning how to code with listeners and background threads.

my unity program stucks when getting files from http server

There are two buttons in my program,
I get the file with bin extension from the address given with the get button. The operation was successful. When I press the test button, it says "test" on the console.
That is all.
However, when I press the get button, I cannot press the test button until the get request is completed. This is my problem.
What I want is that the get request continues in the background and I can click on other buttons.
What would you recommend me to do?
Get Button function :
public void get()
{
StartCoroutine(Get());
}
private IEnumerator Get()
{
string Url = "http://my/local/server/file.bin";
Debug.Log(Url);
using (UnityWebRequest unityWebRequest = UnityWebRequest.Get(Url))
{
yield return unityWebRequest.SendWebRequest();
if (unityWebRequest.isNetworkError || unityWebRequest.isHttpError)
{
Debug.Log("error");
}
else
{
byte[] results = unityWebRequest.downloadHandler.data;
Debug.Log("Received: " + unityWebRequest.downloadHandler.text);
Debug.Log("Size: " + results.Length ); }
}
}
and simple test button :
public void print()
{
Debug.Log("test");
}
As I said, both work separately. What I want is that the Test button is not blocked while doing the getting file from HTTP server.
(btw file size is 100mb)
Just glancing through the documentation, it looks like the lockup may be happening when you call:
byte[] results = unityWebRequest.downloadHandler.data;
The getter on data for the default downloadHandler appears to run a protected method to actually download the content. That download runs on the main thread by default, and is likely what's locking up your UI.
You could confirm this by adding log statements:
Debug.Log("Before get data");
byte[] results = unityWebRequest.downloadHandler.data;
Debug.Log("After get data");
and checking if there's a substantial delay between the two log statements in which the UI is frozen.
If that's the case, it looks like you should be able to attach a custom downloadHandler to run on a background thread and not block the UI thread.
DownloadHandler.GetData
DownloadHandler
To avoid using a custom downloadHandler, you could insert the following
while (!unityWebRequest.downloadHandler.isDone)
yield return null;
byte[] results = unityWebRequest.downloadHandler.data;
The problem may be the Debug.Log you are trying to do. You can delete this line below and try it.
Debug.Log ("Received:" + unityWebRequest.downloadHandler.text);

SignalR Core - Error: Websocket closed with status code: 1006

I use SignalR in an Angular app. When I destroy component in Angular I also want to stop connection to the hub. I use the command:
this.hubConnection.stop();
But I get an error in Chrome console:
Websocket closed with status code: 1006
In Edge: ERROR Error: Uncaught (in promise): Error: Invocation canceled due to connection being closed. Error: Invocation canceled due to connection being closed.
It actually works and connection has been stopped, but I would like to know why I get the error.
This is how I start the hub:
this.hubConnection = new HubConnectionBuilder()
.withUrl("/matchHub")
.build();
this.hubConnection.on("MatchUpdate", (match: Match) => {
// some magic
})
this.hubConnection
.start()
.then(() => {
this.hubConnection.invoke("SendUpdates");
});
EDIT
I finally find the issue. Its caused by change streams from Mongo. If I remove the code from SendUpdates() method then OnDisconnected is triggered.
public class MatchHub : Hub
{
private readonly IMatchManager matchManager;
public MatchHub(IMatchManager matchManager)
{
this.matchManager = matchManager;
}
public async Task SendUpdates() {
using (var changeStream = matchManager.GetChangeStream()) {
while (changeStream.MoveNext()) {
var changeStreamDocument = changeStream.Current.FullDocument;
if (changeStreamDocument == null) {
changeStreamDocument = BsonSerializer.Deserialize<Match>(changeStream.Current.DocumentKey);
}
await Clients.Caller.SendAsync("MatchUpdate", changeStreamDocument);
}
}
}
public override async Task OnDisconnectedAsync(Exception exception)
{
await base.OnDisconnectedAsync(exception);
}
}
Method GetChangeStream from the manager.
ChangeStreamOptions options = new ChangeStreamOptions() { FullDocument = ChangeStreamFullDocumentOption.UpdateLookup };
var watch = mongoDb.Matches.Watch(options).ToEnumerable().GetEnumerator();
return watch;
But I don't know how to fix it.
This can be for many reasons but i think it is most likely this one:
I think this is because of how the server is handling the connected / disconnected events. I can't say for sure but the connection closing needs to handled correctly on the server also with code. Try overriding the built in On Connected /Disconnected methods on the server and see. My assumption only is that you're closing it but the server isn't closing properly and therefore not relaying the proper closed response.
found as a comment at : getting the reason why websockets closed with close code 1006
Where you don't need to change the connection/disconection because evrything works fine. But as an answer this one is the most likely.
It throws error because the callback doesn't get clear properly.
And it is caused by the return data from websocket.
normally it should return like
However, for some reason it might return something like
the very last response breaking into 2 pieces
And that causes the issue.
I don't think there is a way to bypass this without changing the source code.
I reported this on github repo as well at here
It turns out that I can just utilize invocation response to notify client to stop the hub. So it doesn't trigger racing issue.

Random "404 Not Found" error on PasrseObject SaveAsynch (on Unity/Win)

I started using Parse on Unity for a windows desktop game.
I save very simple objects in a very simple way.
Unfortunately, 10% of the time, i randomly get a 404 error on the SaveAsynch method :-(
This happen on different kind of ParseObject.
I also isolated the run context to avoid any external interference.
I checked the object id when this error happen and everything looks ok.
The strange thing is that 90% of the time, i save these objects without an error (during the same application run).
Did someone already got this problem ?
Just in case, here is my code (but there is nothing special i think):
{
encodedContent = Convert.ToBase64String(ZipHelper.CompressString(jsonDocument));
mLoadedParseObject[key]["encodedContent "] = encodedContent ;
mLoadedParseObject[key].SaveAsync().ContinueWith(OnTaskEnd);
}
....
void OnTaskEnd(Task task)
{
if (task.IsFaulted || task.IsCanceled)
OnTaskError(task); // print error ....
else
mState = States.SUCEEDED;
}
private void DoTest()
{
StartCoroutine(DoTestAsync());
}
private IEnumerator DoTestAsync()
{
yield return 1;
Terminal.Log("Starting 404 Test");
var obj = new ParseObject("Test1");
obj["encodedContent"] = "Hello World";
Terminal.Log("Saving");
obj.SaveAsync().ContinueWith(OnTaskEnd);
}
private void OnTaskEnd(Task task)
{
if (task.IsFaulted || task.IsCanceled)
Terminal.LogError(task.Exception.Message);
else
Terminal.LogSuccess("Thank You !");
}
Was not able to replicate. I got a Thank You. Could you try updating your Parse SDK.
EDIT
404 could be due to a bad username / password match. The exception messages are not the best.

Invalid attempt to call FieldCount when reader is closed

The error above occurs when I try to do a dataReader.Read on the data recieved from the database. I know there are two rows in there so it isnt because no data actually exists.
Could it be the CommandBehavior.CloseConnection, causing the problem? I was told you had to do this right after a ExecuteReader? Is this correct?
try
{
_connection.Open();
using (_connection)
{
SqlCommand command = new SqlCommand("SELECT * FROM Structure", _connection);
SqlDataReader dataReader = command.ExecuteReader(CommandBehavior.CloseConnection);
if (dataReader == null) return null;
var newData = new List<Structure>();
while (dataReader.Read())
{
var entity = new Structure
{
Id = (int)dataReader["StructureID"],
Path = (string)dataReader["Path"],
PathLevel = (string)dataReader["PathLevel"],
Description = (string)dataReader["Description"]
};
newData.Add(entity);
}
dataReader.Close();
return newData;
}
}
catch (SqlException ex)
{
AddError(new ErrorModel("An SqlException error has occured whilst trying to return descendants", ErrorHelper.ErrorTypes.Critical, ex));
return null;
}
catch (Exception ex)
{
AddError(new ErrorModel("An error has occured whilst trying to return descendants", ErrorHelper.ErrorTypes.Critical, ex));
return null;
}
finally
{
_connection.Close();
}
}
Thanks in advance for any help.
Clare
When you use the Using in C#, after the last } from the using, the Connection automatically close, thats why you get the fieldcount to be closed when u try to read him, as that is impossible, because u want those datas, read then before close the using, or u can open and close manually the connection, by not using the (using)
Your code, as displayed is fine. I've taken it into a test project, and it works. It's not immediately clear why you get this message with the code shown above. Here are some debugging tips/suggestions. I hope they're valuable for you.
Create a breakpoint on the while (dataReader.Read()). Before it enters its codeblock, enter this in your Immediate or Watch Window: dataReader.HasRows. That should evaluate to true.
While stopped on that Read(), open your Locals window to inspect all the properties of dataReader. Ensure that the FieldCount is what you expect from your SELECT statement.
When stepping into this Read() iteration, does a student object get created at all? What's the value of dataReader["StructureID"] and all others in the Immediate Window?
It's not the CommandBehavior.CloseConnection causing the problem. That simply tells the connection to also close itself when you close the datareader.
When I got that error, it happened to be a command timeout problem (I was reading some large binary data). As a first attempt, I increased the command timeout (not the connection timeout!) and the problem was solved.
Note: while attempting to find out the problem, I tried to listen to the (Sql)connection's StateChanged event, but it turned out that the connection never fall in a "broken" state.
Same problem here. Tested all the above solutions
increase command timeout
close the connection after read
Here's the code
1 objCmd.Connection.Open()
2 objCmd.CommandTimeout = 3000
3 Dim objReader As OleDbDataReader = objCmd.ExecuteReader()
4 repeater.DataSource = objReader
5 CType(repeater, Control).DataBind()
6 objReader.Close()
7 objCmd.Connection.Dispose()
Moreover, at line 4 objReader has Closed = False
I got this exception while using the VS.NET debugger and trying to examine some IQueryable results. Bad decision because the IQueryable resulted in a large table scan. Stopping and restarting the debugger and NOT trying to preview this particular IQueryable was the workaround.