I have silver light application.in the client side i have list of Guid using that Guid i can retrieve all data of customer when i am selecting 26 clients it works fine but when i tried to accessed data more then 26 clients it gives me error like
Load Opration failed for query GetAtclientsERCWithAllInformation the remote server not found
my client side look like
var query = formscontext.GetATClientsERCWithAllInformationQuery(guid);
try
{
LoadOperation<ATClient> _loadReturnTypeOperation = formscontext.Load(query);
_loadReturnTypeOperation.Completed += (s, e) =>
{
some code goes here
}
my server side look like
[Query(HasSideEffects=true)]
public IQueryable<ATClient> GetATClientsERCWithAllInformation(List<Guid> clientsGuids)
{
return this.ObjectContext.ATClients.Include("ClientEfileInfo").Include("ATClientImages").Include("ATPreparer").Include("ATPreparer.ATFirm").Include("ATClientReturns")
.Include("ATClientReturns.ATForms").Include("ATClientReturns.ATForms.FormsMaster").Where(p => clientsGuids.Contains(p.ClientGUID));
}
It seems that EF can't handle the query you requested. The error that silverlight is reporting is useless, you should look into the http response (remember that from an http perspective you're just doing a POST).
Override the
protected override void OnError(DomainServiceErrorInfo errorInfo)
on your domainservice class in order to get the real error. Another quick way to get the error is to setup an http proxy and inspect the response (you can use fiddler + wcf binary inspector from msdn)
Related
Have hard time to get push notifications from server when using MSSQL scalling.
Message flow is one way from server to subscribers (are distributed by groups)
Push messages are not received on UI with the following host configuration:
GlobalHost.DependencyResolver.UseSqlServer(new SqlScaleoutConfiguration(ConfigurationManager.ConnectionStrings["SignalR"].ConnectionString));
Messages are created in SignalRDb and records are present in tables. However they do not reach UI. With SQL scaling disabled all messages propagates to UI successfully.
Here is my Notification code:
public void OnNext(ResultModel value)
{
Clients.Group(group).notify(value);
}
OnNext method always executes witho or without Scalling also group and value are correct. No exceptions thrown on UI or beckend. Below is UI part:
var hubProxy = $.connection.visitsHub;
hubProxy.client.notify = function (updatedResult) {
console.log(updatedResult.Id);
});
};
Any help is appreciated.
tl;dr What is the best way to pass binary data (up to 1MBish) from a WPF application to a WebAPI service method?
I'm currently trying to pass binary data from a WPF application to a WebAPI web service, with variable results. Small files (< 100k) generally work fine, but any larger and the odds of success reduce.
A standard OpenFileDialog, and then File.ReadAllBytes pass the byte[] parameter into the client method in WPF. This always succeeds, and I then post the data to WebAPI via a PostAsync call and a ByteArrayContent parameter.
Is this the correct way to do this? I started off with a PostJSONAsync call, and passed the byte[] into that, but thought the ByteArrayContent seemed more appropriate, but neither work reliably.
Client Method in WPF
public static async Task<bool> UploadFirmwareMCU(int productTestId, byte[] mcuFirmware)
{
string url = string.Format("productTest/{0}/mcuFirmware", productTestId);
ByteArrayContent bytesContent = new ByteArrayContent(mcuFirmware);
HttpResponseMessage response = await GetClient().PostAsync(url, bytesContent);
....
}
WebAPI Method
[HttpPost]
[Route("api/productTest/{productTestId}/mcuFirmware")]
public async Task<bool> UploadMcuFirmware(int productTestId)
{
bool result = false;
try
{
Byte[] mcuFirmwareBytes = await Request.Content.ReadAsByteArrayAsync();
....
}
Web Config Settings
AFAIK these limits in web.config should be sufficient to allow 1MB files through to the service?
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="1073741824" />
</requestFiltering>
</security>
<httpRuntime targetFramework="4.5" maxRequestLength="2097152"/>
I receive errors in WebAPI when calling ReadAsByteArrayAsync(). These vary, possibly due to the app pool in IIS Express having crashed / getting into a bad state, but they include the following (None of which have lead to any promising leads via google):
Specified argument was out of the range of valid values. Parameter name: offset
at System.Web.HttpInputStream.Seek(Int64 offset, SeekOrigin origin)\r\n
at System.Web.HttpInputStream.set_Position(Int64 value)\r\n at System.Web.Http.WebHost.SeekableBufferedRequestStream.SwapToSeekableStream()\r\n at System.Web.Http.WebHost.Seek
OR
Message = "An error occurred while communicating with the remote host. The error code is 0x800703E5."
InnerException = {"Overlapped I/O operation is in progress. (Exception from HRESULT: 0x800703E5)"}
at System.Web.Hosting.IIS7WorkerRequest.RaiseCommunicationError(Int32 result, Boolean throwOnDisconnect)\r\n
at System.Web.Hosting.IIS7WorkerRequest.ReadEntityCoreSync(Byte[] buffer, Int32 offset, Int32 size)\r\n
at System.Web.Hosting.IIS7WorkerRequ...
Initially I thought this was most likely down to IIS Express limitations (running on Windows 7 on my dev pc) but we've had the same issues on a staging server running Server 2012.
Any advice on how I might get this working would be great, or even just a basic example of uploading files to WebAPI from WPF would be great, as most of the code I've found out there relates to uploading files from multipart forms web pages.
Many thanks in advance for any help.
tl;dr It was a separate part of our code in the WebApi service that was causing it to go wrong, duh!
Ah, well, this is embarrassing.
It turns out our problem was down to a Request Logger class we'd registered in WebApiConfig.Register(HttpConfiguration config), and that I'd forgotten about.
It was reading the request content via async as StringContent, and then attempting to log it to the database in an ncarchar(max) field. This itself is probably OK, but I'm guessing all the weird problems started occurring when the LoggingHandler as well as the main WebApi controller, were both trying to access the Request content via async?
Removing the LoggingHandler fixed the problem immediately, and we're now able to upload files of up to 100MB without any problems. To fix it more permanently, I guess I rewrite of the LoggingHandler is required to set a limit on the maximum content size it tries to log / to ignore certain content types.
It's doubtful, but I hope this may be of use for someone one day!
public class LoggingHandler : DelegatingHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
LogRequest(request);
return base.SendAsync(request, cancellationToken).ContinueWith(task =>
{
var response = task.Result;
// ToDo: Decide if/when we need to log responses
// LogResponse(response);
return response;
}, cancellationToken);
}
private void LogRequest(HttpRequestMessage request)
{
(request.Content ?? new StringContent("")).ReadAsStringAsync().ContinueWith(x =>
{
try
{
var callerId = CallerId(request);
var callerName = CallerName(request);
// Log request
LogEntry logEntry = new LogEntry
{
TimeStamp = DateTime.Now,
HttpVerb = request.Method.ToString(),
Uri = request.RequestUri.ToString(),
CorrelationId = request.GetCorrelationId(),
CallerId = callerId,
CallerName = callerName,
Controller = ControllerName(request),
Header = request.Headers.ToString(),
Body = x.Result
};
...........
I'm developing a class library that contains generic methods for these scenarios:
Live support chat (1 on 1 private text chat, with many admins and guests)
Rooms with many users where you can send broadcast and private messages
These two features above are already implemented and now it's necessary for my application to save messages.
My question is, what is the best way to store chat conversations in a SQL database:
Everytime I click send, I insert the message in the database?
Create a List for each user and everytime I click send, the message is saved on the list of the user who sent the message. Then if a user disconnects, I'm going to iterate the list of messages and for each message insert all of them in the db.
Are there other solutions?
What I'm doing now is the following. I have this method which is located on my Hub class:
public void saveMessagetoDB(string userName, string message)
{
var ctx = new TestEntities1();
var msg = new tbl_Conversation {Msg = message};
ctx.tbl_Conversation.Add(msg);
ctx.SaveChanges();
}
I call this method saveMessagetoDB on my client side HTML file like this:
$('#btnSendMessage').click(function () {
var msg = $("#txtMessage").val();
if (msg.length > 0) {
var userName = $('#hUserName').val();
// <<<<<-- ***** Return to Server [ SaveMessagetoDB ] *****
objHub.server.saveMessagetoDB(userName, msg);
SignalR is great for a chat application and you wouldn't even need to store anything in SQL unless you want to create a transcript of the chat at a later time (which may not even be necessary).
I suggest getting the chat working with SignalR first (don't do anything with sql). Then once that is working you can put SQL logging as necessary in your signalR hub.
It most likely makes the most sense to write to sql on each message.
If you decide to store the chats in a database, then you will need to insert/update the messages as they happen.
If you are using the PersistentConnection then you can hook into the OnReceivedAsync event and insert / update data from that event:
protected override Task OnConnectedAsync(IRequest request, string connectionId)
{
_clients.Add(connectionId, string.Empty);
ChatData chatData = new ChatData("Server", "A new user has joined the room.");
return Connection.Broadcast(chatData);
}
Or in the SignalR class that inherits from Hub, you can persist to the Db right before you have notified any clients.
I'm trying to implement pagination using App Engine's RPC and GWT (it's an app engine connected project).
How can I pass both the query results and the web-safe cursor object to the GWT client from the RPC?
I've seen examples using a servlet but I want to know how to do it without a servelt.
I've considered caching the cursor on the server using memcache but I'm not sure if that's appropriate or what should be used as the key (session identifier I would assume, but I'm not sure how those are handled on App Engine).
Links to example projects would be fantastic, I've been unable to find any.
OK, so the best way to do this is to store the cursor as a string on the client.
To do this you have to create a wrapper class that is transportable so you can pass back it to the client via RequestFactory that can hold the results list and the cursor string. To do that you create a normal POJO and then a proxy for it.
here's what the code looks like for the POJO:
public class OrganizationResultsWrapper {
public List<Organization> list;
public String webSafeCursorString;
public List<Organization> getList() {
return list;
}
public void setList(List<Organization> list) {
this.list = list;
}
public String getWebSafeCursorString() {
return this.webSafeCursorString;
}
public void setWebSafeCursorString(String webSafeCursorString) {
this.webSafeCursorString = webSafeCursorString;
}
}
for the proxy:
#ProxyFor(OrganizationResultsWrapper.class)
public interface OrganizationResultsWrapperProxy extends ValueProxy{
List<OrganizationProxy> getList();
void setList(List<OrganizationProxy> list);
String getWebSafeCursorString();
void setWebSafeCursorString(String webSafeCursorString);
}
set up your service and requestFactory to use the POJO and proxy respectively
// service class method
#ServiceMethod
public OrganizationResultsWrapper getOrganizations(String webSafeCursorString) {
return dao.getOrganizations(webSafeCursorString);
}
// request factory method
Request<OrganizationResultsWrapperProxy> getOrganizations(String webSafeCursorString);
Then make sure and run the RPC wizard so that your validation process runs otherwise you'll get a request context error on the server.
Here's the implementation in my data access class:
public OrganizationResultsWrapper getOrganizations(String webSafeCursorString) {
List<Organization> list = new ArrayList<Organization>();
OrganizationResultsWrapper resultsWrapper = new OrganizationResultsWrapper();
Query<Organization> query = ofy().load().type(Organization.class).limit(50);
if (webSafeCursorString != null) {
query = query.startAt(Cursor.fromWebSafeString(webSafeCursorString));
}
QueryResultIterator<Organization> iterator = query.iterator();
while (iterator.hasNext()) {
list.add(iterator.next());
}
resultsWrapper.setList(list);
resultsWrapper.setWebSafeCursorString(iterator.getCursor().toWebSafeString());
return resultsWrapper;
}
a second option would be to save the webSafeCursorString in the memcache, as you already mentioned.
my idea looks like this:
the client sends always request like this "getMyObjects(Object... myParams, int maxResults, String clientPaginationString)". the clientPaginationString is uniquely created like shown below
server receives request and looks into the memcache if there is a webSafeCursorString for the key clientPaginationString
if the server finds nothing, he creates the query and save the webSafeCursorString into memcache with the clientPaginationString as the key. -> returns the results
if the server finds the webSafeCursorString he restarts the query with it and returns the results
the problems are how to clean the memcache and how to find a unique clientPaginationString:
a unique clientPaginationString should be the current UserId + the params of the current query + timestemp. this should work just fine!
i really can't think of a easy way how to clean the memcache, however i think we do not have to clean it at all.
we could store all the webSafeCursorStrings and timestemps+params+userid in a WebSafeCursor-Class that contains a map and store all this in the memcache... and clean this Class ones in a while (timestamp older then...).
one improvement i can think of is to save the webSafeCursorString in the memcache with a key that is created on the server (userSessionId + servicename + servicemethodname + params). however, important is that the client sends an information if he is interested in a new query (memcache is overriden) or wants the next pagination results (gets webSafeCursorString from memcache). a reload of the page should work. a second tap in the browser would be a problem i think...
what would you say?
I have a Visual Studio solution with a Silverlight project, and a web project which hosts the Silverlight app. The web project also contains an ASMX web service which is called by the Silverlight ap.
As described below, certain calls to the web service work fine, and yet others cause a CommunicationException to be thrown, wrapping a WebException - both with the message "The server returned the following error: 'not found'".
Firstly, here's my original method, which failed as described above (entity names changed for simplicity):
[WebMethod]
public Customer GetCustomer(int id)
{
CustomerDataContext dc = new CustomerDataContext();
return dc.Customers.SingleOrDefault(x => x.Id == id);
}
Secondly, to debug the problem I took Linq to SQL and the database out of the picture, and the below code worked fine:
[WebMethod]
public Customer GetCustomer(int id)
{
Customer c = new Customer() { ID=1, Name="Bob", History = new EntitySet<CustomerHistory>() };
return c;
}
Third, thinking about this, one difference between the two methods is that the first one would include values in the customer history. I extended the second method to include this, and it started failing again:
[WebMethod]
public Customer GetCustomer(int id)
{
Customer c = new Customer() { ID=1, Name="Bob", History = new EntitySet<CustomerHistory>() };
c.History.Add(new CustomerHistory() { Id=1, CustomerId=1, Text="bla" });
return c;
}
I'm stuck with regards to how to progress - my current thinking is that this could be a deserialization issue on the Silverlight side, when the object graph is deeper. This rationally doesn't make sense, but I can't think of anything else. I've confirmed that the transfer size and buffer size are big enough (2GB by default).
Any pointers would be appreciated.
Ahhhh the famous "Not Found" error, try to get details from that error using the tag in your web.config. That will create a log file providing details of the error.
The following link explains exaclty how to do it :
http://blogs.runatserver.com/lppinson/post/2010/04/15/Debugging-WCF-Web-Services.aspx