I need to be able to create an event processing rule that when you add a new device, you take a string value from one fragment (e.g.: c8y_Hardware.imei) and use that string to populate another fragment (e.g: c8y_Mobile.imei). So the new device would then have the same value in both c8y_Hardware.imei and c8y_Mobile.imei.
We have attempted setting up the appropriate CEP rules, but they are not working (they do compile and save).
insert into UpdateManagedObject
select
m.id as id,
{
"c8y_Mobile.imei", getString(m,"c8y_Hardware.imei")
} as fragments
from
ManagedObjectCreated as m
where
getString(m,"c8y_Hardware.imei") != "";
Any guidance on where we are messing up our syntax would be greatly appreciated.
It should be: m.managedObject.id as id.
Usually you would also get an error on compile but it can be that the streams also have an id so that it technically works in CEP. You should be able to check if it triggers on the debug stream and see the id that has been set.
Same applies for all other Cumulocity streams. The streams itself e.g. ManagedObjectCreated or AlarmUpdated etc. are not the objects directly. They have always a property like in this case managedObject or for AlarmUpdated it is alarm. This property is the actual payload.
The helper methods like getString are written in a way that you can pass either the payload or the full stream object so there it does not matter.
Related
I am trying to log field writes with bytebuddy. After reading some earlier posts, I started using MemberSubstitution and got something going using the following code:
private static Method FIELD_INTERCEPTOR = // reflective reference to interceptFieldWrite
AsmVisitorWrapper VISITOR = MemberSubstitution.relaxed()
.field(ElementMatchers.any())
.onWrite()
.replaceWith(FIELD_INTERCEPTOR)
.on(ElementMatchers.isMethod());
..
public static void interceptFieldWrite(Object object,Object value) {
System.out.println("intercepted field write in object " + object + " , attempt to set value to " + value);
}
..
The part I am struggling with is how to pass a reference to the field for which the access is intercepted to interceptFieldWrite (as string or instance of Field). If possible I would of course like to avoid reflection completely. I don't actually want to completely substitute field access, but just want to add a method with some checks just before it takes place. Is there a feature in bytebuddy to do this, or do I have to use something more low-level than ASM to achieve this ?
Byte Buddy offers this but you will have to compose your own StackManipulations to do so. The mechanism in MemberSubstitution is called replaceWithChain. Here you specify Steps where each step can do what you intend:
invoke a method via MethodInvocation.
write a field via FieldAccessor.
You will have to load the arguments to the method call and the field access prior to using the above stack manipulations via the MethodVariableAccess where the targeted element's offsets are represented by offsets.
In your case, this would require to read the target instance via
MethodVaribaleAccess.of(parameters.get(0)).loadFrom(offsets.get(0));
MethodVaribaleAccess.of(parameters.get(1)).loadFrom(offsets.get(1));
and the to execute the method or field write in question. The targeted field will be passed as target, you can cast it to FieldDescription if you only ever intercept fields.
Make sure you only intercept non-static fields where the this instance will not be passed.
I'm trying to force CAN signals to given values using COM interface of CANalyzer. Since there is no COM method to send CAN messages, I'm implementing a workaround using CAPL:
void SendMySignal(int value) {
message MyMessage msg;
msg.MySignal = value;
output(msg);
}
This works fine, however since MyMessage and MySignal are referenced statically (by name) here, I'll have to implement N functions to be able to send N signals (or an N-way switch statement, etc). Is there a way to avoid the hassle and access signals inside a message by string? Something like this:
void SendSignal(int MessageID, char SignalName, int value)
I'm also open to alternative solutions in case I have missed something in the COM interface. If there is a solution which only works for CANoe, I can ask my boss for a license, but of course I'd prefer to do without.
there is such function, but it is restricted to be used only in test nodes
long setSignal(char signalName[], double aValue);
you can find details in:
CAPL Function Overview » Test Feature Set / Signal Access » SetSignal
Special Use Case: Signal is not known before Measurement Start
and take care about not to send for each signal a new message to avoid bus over-flooding. In my opinion it is a better style to set all signals for whole message and to send it on change only when it is not cyclic. Signal updates in cyclic messages mostly have to be sent in next cycle.
I am using signalr-objc currently and trying to make an app that interacts with another web app. The hub has been written so that it returns values and the javascript is able to get these and perform certain actions depending on the return.
I want to try and do the same with in objective-c but I am not sure how to write it. I use this line to join a group.
[myhub invoke:#"joinGroup" withArgs:joinParam];
and something like
int join = [myhub invoke:#"joinGroup" withArgs:joinParam];
does not seem right. So is there some way of doing this??
Since -invoke:withArgs: returns no value, you're not doing the right thing trying to assign a value to join.
If you need to determine if there was a server response, you'd be better off using the alternate -invoke:withArgs:continueWith:. The block you provide to the latter argument receives an object (a reply from the server); at the very least, you could check it inside that block to be sure it's not nil.
I have a problem with the sequence model seen in the diagram below, specifically where the System object is creating a new Number. In this case, there is no need for a return message since the function SaveInput(n), both in System and Number, is the end of the line for that portion of the program, but unless I include one, the modeller reshaped my diagram into the other one I've uploaded here, and I can't see how to arrange the messages so that my program will work the way I intend without including the return message (the one without a name) from Number to System, since the functions SaveInput() both return a void.
How should void-returning functions be handled in sequence diagrams so that they behave correctly? I have opened the message properties and explicitly defined it as returning a void, but that hasn't helped.
When A calls operation b in B, the "return" arrow from B to A indicates the end of the operation b has finished its execution. This doesn´t mean that as part of the return message you have to return a value, it only means that the execution is done and you can continue with the next messages. Visually, most tools also use these return messages to manage the life bar of the object.
I am writing an Eclipse plug-in that uses JDT AST's ASTParser to parse a method. I am looking within that method for the creation of a particular type of object.
When I find a ClassInstanceCreation, I call getType() on it to see what type is being instantiated. I want to be sure that the fully-resolved type being dealt with there is the one I think it is, so I tell the resultant Type object to resolveBinding(). I get null back even though there are no compilation errors and even though I called setResolveBindings(true) on my ASTParser. I gave my ASTParser (via setSource()) the ICompilationUnit that contains my method, so the parser has access to the entire workspace context.
final IMethod method = ...;
final ASTParser parser = ASTParser.newParser(AST.JLS3);
parser.setResolveBindings(true);
parser.setSource(method.getCompilationUnit());
parser.setSourceRange(method.getSourceRange().getOffset(), method.getSourceRange().getLength());
parser.setKind(ASTParser.K_CLASS_BODY_DECLARATIONS);
final TypeDeclaration astRoot = (TypeDeclaration) parser.createAST(null);
final ClassInstanceCreation classInstanceCreation = walkAstAndFindMyExpression(astRoot);
final Type instantiatedType = classInstanceCreation.getType();
System.out.println("BINDING: " + instantiatedType.resolveBinding());
Why does resolveBinding() return null? How can I get the binding information?
Tucked away at the bottom of the overview of ASTParser.setKind(), carefully hidden from people troubleshooting resolveBinding() and setResolveBindings(), is the statement
Binding information is only computed when kind is K_COMPILATION_UNIT.
(from the online Javadoc)
I don't understand offhand why this would be the case, but it does seem to point pretty clearly at what needs to be different!