Im trying to connect a Flash client to BlazeDS. There has been some success with this from others using the vanilla BlazeDS setup. However I'm using the new Spring BlazeDS Integration from springsource and running aground.
The flash client actually seems to be working in that I can see the correct data in the body of the returned object, but for some reason unknown it fails casting as an IMessage. It fails in PollingChannel.as on this line with the subject line error
var messageList:Array = msg.body as Array;
for each (var message:IMessage in messageList) <--
On application load I register a whole bunch of classes like so
registerClassAlias( "flex.messaging.messages.RemotingMessage", RemotingMessage );
registerClassAlias("mx.messaging.messages.IMessage", IMessage);
etc..
my code is basically
var channelSet:mx.messaging.ChannelSet = new mx.messaging.ChannelSet();
var channel:mx.messaging.channels.AMFChannel = new AMFChannel("my-amf", "http://localhost:8400/SpringA/messagebroker/amf");
channelSet.addChannel(channel);
var consumer:mx.messaging.Consumer = new Consumer();
consumer.channelSet = channelSet;
consumer.destination = "simple-feed";
consumer.subscribe();
consumer.addEventListener(MessageEvent.MESSAGE, test);
private function test(event:IMessage)
{
trace("msg..");
// breakpoint never makes it here
}
I have a flex client which works 100% with same destination/channel.
The error in the title means that you, for some reason, got an object that is not implementing or extending the IMessage interface, therefore the loop can not cast it in this part:
for each (var message:IMessage in messageList){
Either you should somehow make sure that you don't add anything that is not extending or implementing IMessage, or check if the variable IS actually ext./imp. it. Also - if you want to do that, you will have to change the for each like this:
for each (var obj in messageList){
if (obj is IMessage){
var message:IMessage = obj as IMessage;
// DO STUFF HERE
}
}
Add this Object mapping:
registerClassAlias("flex.messaging.io.ObjectProxy", ObjectProxy);
If on your Java VO objects you have overridden the hashcode() method, this situation could happen.
Remove the hashcode() override (if you are able to).
See my blog for the backstory on how I discovered this. http://squaredi.blogspot.com/2013/12/remoting-landmine-without-stack-trace.html
I had the same error when trying to send an actionscript object to the backend. My problem was that my c# equivalent object was missing an public parameterless constructor.
Related
Below is a minimal example of the problem I am currently encountering:
using System.Net.WebSockets;
using AutoFixture;
using AutoFixture.AutoMoq;
using FluentAssertions;
using Xunit;
...
[Fact]
public void Test1()
{
var fixture = new Fixture().Customize(new AutoMoqCustomization() { ConfigureMembers = true });
var sut = fixture.Create<WebSocket>();
sut.Should().NotBeNull();
}
[Fact]
public void Test2()
{
var fixture = new Fixture().Customize(new AutoMoqCustomization() { ConfigureMembers = true });
var sut = new Mock<WebSocket>().Object;
fixture.Inject(sut);
sut.Should().NotBeNull();
}
...
When I run the first test, I get the following exception:
AutoFixture.ObjectCreationExceptionWithPath : AutoFixture was unable to create an instance from Moq.Mock`1[System.IO.Stream] because creation unexpectedly failed with exception. Please refer to the inner exception to investigate the root cause of the failure.
Inner exception messages:
System.BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)
The second test succeeds.
I would like to be able to create an instance of a class using AutoFixture which takes a WebSocket as a constructor parameter, without the need to inject a mock object first (ultimately, so that I can use an AutoMoqData attribute, and get rid of some boilerplate). Have I got any misusage or misunderstanding going on here, or would this be better placed as a GitHub issue? In the interim, is there anything I can do to work around this issue?
You observe this issue because of the AutoFixture's factory discovery strategy. When you try to create an object of an abstract type, AutoFixture still inspects the type to find a static factory method to activate the object. In your particular case, the WebSocket type contains such methods, so some of them is used. It looks like it doesn't work well with auto-generated input values, so fails with an exception.
You can customize AutoFixture, to always mock the WebSocket type:
fixture.Register((Mock<WebSocket> m) => m.Object);
Just tested with the latest versions of products (AutoFixture 4.5.0, Moq 4.10.0) and it works like a charm.
In my attempt to learn flex remoting I came across this
flexService.getRules.addEventListener(ResultEvent.RESULT, loadRules);
here flexService is a remote java object .. In above function call can any one help me that when ResultEvent.RESULT will occur. On studying about ResultEvent in AS document it states as
The event that indicates an RPC operation has successfully returned a result
So keeping that in mind my guess is ResultEvent will be fired when flexService.getRules method will successfully return a list of object,where flexService is object of remote class FlexService having getRules function which returns list of object, Can any one please tell how exactly it works..
Also can some one plz tell me how eventListener can be added to a list of object
PS: I am using Spring as backend
Here you set result to arraycollection
private function loadRules(event:ResultEvent):void
{
var list:ArrayCollection = new ArrayCollection();
list = event.result as ArrayCollection;
}
I'll be going on assumptions since you apparently aren't keen on showing more code or giving pertinent information.
I'm assuming that 'flexService' is a RemoteObject that has set all required properties (destination, endpoint, etc)
I'm assuming that 'getRules' is an available function on your java remote class which returns the information needed.
I'm assuming that everything is being sent over using AMF.
in that case, it's as simple as doing this:
var token:ASyncToken = flexService.getRules(arg1, arg2);
token.addResponder(new Responder(yourResultFunction, yourFaultFunction));
private function yourResultFunction(data:Object):void
{
// Do something with data here
}
private function yourFaultFunction(fault:Object):void
{
// do something if a fault happens
}
Of course, this is very basic and you should try to implement a better pattern (commands) around it.
So, there are a wealth of Flex articles online about how to handle a .NET WebMethod that returns a DataSet or DataTable. Here is an example:
Handling web service results that contain .NET DataSets or DataTables
So, I know how to use result.Tables.<tablename>.Rows and the like. But what I cannot seem to figure out or find online is how to go the other direction - a method to pass objects or tables back to the .NET Webservice from Flex, without stooping to passing XML as a string, or making huge web service methods that have one parameter for each property/column of the object being stored. Surely others, smarter than I, have tackled this issue.
I am using ASP.NET 2.0 Typed DataSets, and it would be really nice if I could just pass one object or array of objects from Flex to the web service, populate my Typed DataTable, and do an Update() through the corresponding typed TableAdapter. My dream would be a [WebMethod] something like one of these:
public void SaveObject(TypedDataTable objToSave) { ... }
public void SaveObject(TypedDataSet objToSave) { ... }
I've had the typed datatables saving to the database, I know how to do that part and even a few tricks, but we had XML being passed back-and-forth as a string - eww. I'm trying to get to a more object-based approach.
The best object based approach is AMF. I assume its probably a bit late in your your development cycle to change your integration layer, but otherwise I dont know of a way to get around marshalling your object(s) back into XML or separating them out into their primitive components.
For .NET implementations of AMF check out:
FlourineFX(FOSS)
WebORB for .NET
Its amazing how easy things become once AMF is used, for example using the Mate MVC framework and an AMF call passing a complex object to the server looks something like this:
<mate:RemoteObjectInvoker instance="yourWebservice" method="saveComplexObject" showBusyCursor="true" >
<mate:resultHandlers>
<mate:CallBack method="saveComplexObjectSuccess" arguments="{[resultObject]}" />
</mate:resultHandlers>
<mate:faultHandlers>
<mate:MethodInvoker generator="{DataManager}" method="presentFault" arguments="{fault}" />
</mate:faultHandlers>
</mate:RemoteObjectInvoker>
With result and fault handlers being optional.
The direction I ended up going was close to what I hoped was possible, but is "hack-ish" enough that I would consider SuperSaiyen's suggestion to use AMF/ORM a better solution for new/greenfield projects.
For sake of example/discussion, let's say I am working with a Person table in a database, and have a typed DataSet called PeopleDataSet that has PersonTableAdapter and PersonDataTable with it.
READ would look like this in .NET web service:
[WebMethod]
public PeopleDataSet.PersonDataTable GetAllPeople() {
var adapter = new PersonTableAdapter();
return adapter.GetData();
}
... which in Flex would give you a result Object that you can use like this:
// FLEX (AS3)
something.dataProvider = result.Tables.Person.Rows;
Check out the link I put in the question for more details on how Flex handles that.
CREATE/UPDATE - This is the part I had to figure out, and why I asked this question. The Flex first this time:
// FLEX (AS3)
var person:Object = {
PersonID: -1, // -1 for CREATE, actual ID for UPDATE
FirstName: "John",
LastName: "Smith",
BirthDate: "07/19/1983",
CreationDate: "1997-07-16T19:20+01:00" // need W3C DTF for Date WITH Time
};
_pplWebSvcInstance.SavePerson(person); // do the web method call
(For handling those W3C datetimes, see How to parse an ISO formatted date in Flex (AS3)?)
On the .NET web service side then, the trick was figuring out the correct Type on the web method's parameter. If you go with just Object, then step into a call with a debugger, you'll see .NET figures it is a XmlNode[]. Here is what I figured out to do:
[WebMethod]
public int SavePerson(PeopleDataSet p) {
// Now 'p' will be a PeopleDataSet with a Table called 'p' that has our data
// row(s) (just row, in this case) as string columns in random order.
// It WILL NOT WORK to use PeopleDataSet.PersonDataTable as the type for the
// parameter, that will always result in an empty table. That is why the
// LoadFlexDataTable utility method below is necessary.
var adapter = new PersonTableAdapter();
var tbl = new PeopleDataSet.PersonDataTable();
tbl.LoadFlexDataTable(p.Tables[0]); // see below
// the rest of this might be familiar territory for working with DataSets
PeopleDataSet.PersonRow row = tbl.FirstOrDefault();
if (row != null) {
if (row.PersonID > 0) { // doing UPDATE
row.AcceptChanges();
row.SetModified();
}
else { // doing CREATE
row.CreationDate = DateTime.UtcNow; // set defaults here
row.IsDeleted = false;
}
adapter.Update(row); // database call
return row.PersonID;
}
return -1;
}
Now, the kluge utility method you saw called above. I did it as extension method, that is optional:
// for getting the Un-Typed datatable Flex gives us into our Typed DataTable
public static void LoadFlexDataTable(this DataTable tbl, DataTable flexDataTable)
{
tbl.BeginLoadData();
tbl.Load(flexDataTable.CreateDataReader(), LoadOption.OverwriteChanges);
tbl.EndLoadData();
// Probably a bug, but all of the ampersand (&) in string columns will be
// unecessarily escaped (&) - kluge to fix it.
foreach (DataRow row in tbl.Rows)
{
row.SetAdded(); // default to "Added" state for each row
foreach (DataColumn col in tbl.Columns) // fix & to & on string columns
{
if (col.DataType == typeof(String) && !row.IsNull(col))
row[col] = (row[col] as string).Replace("&", "&");
}
}
}
I'm developing a Flex application and am having some trouble working with asynchronous calls. This is what I would like to be able do:
[Bindable] var fooTypes : ArrayCollection();
for each (var fooType : FooType in getFooTypes()) {
fooType.fooCount = getFooCountForType(fooType);
itemTypes.addItem(fooType);
}
The issue I'm running into is that both getFooTypes and getFooCountForType are asynchronous calls to a web service. I understand how to populate fooTypes by setting a Responder and using ResultEvent, but how can I call another service using the result? Are there any suggestions/patterns/frameworks for handling this?
If possible, I Strongly recommed re-working your remote services to return all the data you need in one swoop.
But, if you do not feel that is possible or practical for whatever reason, I would recommend doing some type of remote call chaining.
Add all the "remote calls" you want to make in array. Call the first one. In the result handler process the results and then pop the next one and call it.
I'm a bit unclear from your code sample when you are calling the remote call, but I assume it part of the getFooCountForType method. Conceptually I would do something like this. Define the array of calls to make:
public var callsToMake : Array = new Array();
cache the currently in process fooType:
public var fooType : FooType;
Do your loop and store the results:
for each (var fooType : FooType in getFooTypes()) {
callsToMake.push(fooType);
// based on your code sample I'm unclear if adding the fooTypes to itemTypes is best done here or in the result handler
itemTypes.addItem(fooType);
}
Then call the remote handler and save the foo you're processing:
fooType = callsToMake.pop();
getFooCountForType(fooTypeToProcess);
In the result handler do something like this:
// process results, possibly by setting
fooType.fooCount = results.someResult;
and call the remote method again:
fooType = callsToMake.pop();
getFooCountForType(fooTypeToProcess);
I've just found a strange error when deserializing from a ByteArray, where Vectors cannot contain types that extend Array: there is a TypeError when they are deserialized.
TypeError: Error #1034: Type Coercion failed: cannot convert []#4b8c42e1 to com.myapp.ArraySubclass.
at flash.utils::ByteArray/readObject()
at com.myapp::MyApplication()[/Users/aaaidan/MyApp/com/myapp/MyApplication.as:99]
Here's how:
public class Application extends Sprite {
public function Application() {
// register the custom class
registerClassAlias("MyArraySubclass", MyArraySubclass);
// write a vector containing an array subclass to a byte array
var vec:Vector.<MyArraySubclass> = new Vector.<MyArraySubclass>();
var arraySubclass:MyArraySubclass = new MyArraySubclass();
arraySubclass.customProperty = "foo";
vec.push(arraySubclass);
var ba:ByteArray = new ByteArray();
ba.writeObject(arraySubclass);
ba.position = 0;
// read it back
var arraySubclass2:MyArraySubclass = ba.readObject() as MyArraySubclass; // throws TypeError
}
}
public class MyArraySubclass extends Array {
public var customProperty:String = "default";
}
It's a pretty specific case, but it seems very odd to me. Anyone have any ideas what's causing it, or how it could be fixed?
well, it seems array serialization is hardcoded. you should definitely post a bug report.
actually the code you posted doesn't throw an error since ba.readObject() as MyArraySubclass is simply null. MyArraySubclass(ba.readObject()) however would.
what you could try to fix it, would be to implement IExternalizable, altough I'm not sure it'll work any better.
I guess the problem is that Array is a very very special class in ActionScript (in the sense that in some way it is nothing more than any other dynamic class, but in other ways it's not at all) which leads to a lot of Array-specific code in the VM. Also, a question is, why do you need to subclass Array?