I have a custom functionality for check_move:
crrm : {
move : {
"check_move" : function (m) {
var p = this._get_parent(m.o);
if(!p)
return false;
if(m.cr===-1)
return false;
return true;
}
}
},
This seems to work as intended.
I then try to bind to the "move_node" event to update my database:
.bind("move_node.jstree",function(event,data){
if(data.rslt.obj.attr("id")==""){
/* I omitted this snippet from this paste - it's really long and it basically does the same thing as below, just gets the node's id in a more complicated way*/
} else {
controller.moveNode(data.rslt.obj.attr("id"),data.inst._get_parent(this).attr("id"),data.rslt.obj.attr("rel"));
}
})
This results in an error. data.rslt.obj is undefined. I'm truly at loss at what to do, I've binded to multiple events before and this is how I've done it.
How can I get node attributes etc after the move_node event, if data.rslt.obj doesn't work?
Oh, the controller.moveNode() is one of my own functions, so don't just copy-paste if you're trying to learn jstree.
I found the answer to my own question pretty soon after asking about it (typical).
One must use data.rslt.o.attr("id") instead of -.obj.- An odd inconsistency if you ask me.
I would delete this post, but I think this could be a pretty common problem. If someone thinks otherwise, feel free to delete.
if(!p)
return false;
if(m.cr===-1)
return false;
return true;
next time try to do it like this:
return (p && m.cr !== -1);
Related
Hey I need some help here for How to use timeouts in flutter correctly. First of all to explain what the main goal is:
I want to recive data from my Firebase RealTime Database but need to secure this request api call with an time out of 15 sec. So after 15 sec my timeout should throw an exception that will return to the Users frontend the alert for reasons of time out.
So I used the simple way to call timeouts on future functions:
This functions should only check if on some firebase node an ID is existing or not:
Inside this class where I have declared this functions I also have an instance which called : timeoutControl this is a class which contains a duration and some reasons for the exceptions.
Future<bool> isUserCheckedIn(String oid, String maybeCheckedInUserIdentifier, String onGateId) async {
try {
databaseReference = _firebaseDatabase.ref("Boarding").child(oid).child(onGateId);
final snapshot = await databaseReference.get().timeout(Duration(seconds: timeoutControl.durationForTimeOutInSec), onTimeout: () => timeoutControl.onEppTimeoutForTask());
if(snapshot.hasChild(maybeCheckedInUserIdentifier)) {
return true;
}
else {
return false;
}
}
catch (exception) {
return false;
}
}
The TimeOutClass where the instance timeoutControl comes from:
class CustomTimeouts {
int durationForTimeOutInSec = 15; // The seconds for how long to try until we throw an timeout exception
CustomTimeouts();
// TODO: Implement the exception reasons here later ...
onEppTimeoutForUpload() {
throw Exception("Some reason ...");
}
onEppTimeoutForTask() {
throw Exception("Some reason ...");
}
onEppTimeoutForDownload() {
throw Exception("Some reason ...");
}
}
So as you can see for example I tried to use this implementation above. This works fine ... sometimes I need to fight with un explain able things -_-. Let me try to introduce what in somecases are the problem:
Inside the frontend class make this call:
bool isUserCheckedIn = await service.isUserCheckedIn(placeIdentifier, userId, gateId);
Map<String, dynamic> data = {"gateIdActive" : isUserCheckedIn};
/*
The response here is an Custom transaction handler which contains an error or an returned param
etc. so this isn't relevant for you ...
*/
_gateService.updateGate(placeIdentifier, gateId, data).then((response) {
if(response.hasError()) {
setState(() {
EppDialog.showErrorToast(response.getErrorMessage()); // Shows an error message
isSendButtonDiabled = false; /*Reset buttons state*/
});
}
else {
// Create an gate process here ...
createGateEntrys(); // <-- If the closures update was successful we also handle some
// other data inside the RTDB for other reasons here ...
}
});
IMPORTANT to know for you guys is that I am gonna use the returned "boolean" value from this function call to update some other data which will be pushed and uploaded into another RTDB other node location for other reasons. And if this was also successful the application is going on to update some entrys also inside the RTDB -->createGateEntrys()<-- This function is called as the last one and is also marked as an async function and called with its closures context and no await statement.
The Data inside my Firebase RTDB:
"GateCheckIns" / "4mrithabdaofgnL39238nH" (The place identifier) / "NFdxcfadaies45a" (The Gate Identifier)/ "nHz2mhagadzadzgadHjoeua334" : 1 (as top of the key some users id who is checked in)
So on real devices this works always without any problems... But the case of an real device or simulator could not be the reason why I'am faceing with this problem now. Sometimes inside the Simulator this Function returns always false no matter if the currentUsers Identifier is inside the this child nodes or not. Therefore I realized the timeout is always called immediately so right after 1-2 sec because the exception was always one of these I was calling from my CustomTimeouts class and the function which throws the exception inside the .timeout(duration, onTimeout: () => ...) call. I couldn't figure it out because as I said on real devices I was not faceing with this problem.
Hope I was able to explain the problem it's a little bit complicated I know but for me is important that someone could explain me for what should I pay attention to if I am useing timeouts in this style etc.
( This is my first question here on StackOverFlow :) )
I'm trying to generate random int and check if the integer is exists in Firebase database, and do this infinitly until the integer is not exist inside database.
Below my code:
while (true) {
_changeRandomInt()
firebaseFirestore.collection("myCollection").doc(_randomInt).get().then((DocumentSnapshot documentSnapshot) {
if (getFromFirebase(documentSnapshot) == null) {
break;
}
});
}
But I cannot even run this code. Error: A break statement can't be used outside of a loop or switch statement. Try removing the break statement. I have my break inside while loop, then why I'm getting this error? How to fix this?
A break statement can't be used outside of a loop or switch statement. Try removing the break statement.
This is self explanatory. You can't use break outside of a loop. Which in your case is inside a future.
Do something like this:
_changeRandomInt();
firebaseFirestore.collection("myCollection").doc(_randomInt).get()
.then((DocumentSnapshot documentSnapshot) {
while (getFromFirebase(documentSnapshot) != null){
//the body of this loop will only execute as long as the value isn't null
//will break out of the loop as soon as the value is null
}
}
The break you have used is inside then(), which means no loop is available immediately above `break. You can refactor your code in this manner to get it working.
while (true) {
_changeRandomInt()
final documentSnapshot = await firebaseFirestore.collection("myCollection").doc(_randomInt).get();
if (getFromFirebase(documentSnapshot) == null) {
break;
}
}
If getFromFirebase is also a future, then await that as well inside if block.
You want to do something like this:
void functionName() async {
try{
var ans;
while(getFromFirebae(ans)== null){
ans = await firebaseFirestore.collection("myCollection").doc(_randomInt).get();
}
} catch(e){
//error
}
}
However, this is not the correct way. A good practice is to create a loading widget, that would show an animation while the future is loading. An even better way - to load everything in the background without stalling the overall app.
Some people have been saying that you're using "break inside a Future", but that's not quite right. Your problem is that you're using break inside of a separate function body. This is equivalent to writing:
void f() {
break;
}
which doesn't make sense since break is not used directly within a local loop or switch statement. It doesn't matter that you're creating your function within a loop; break and continue statements perform local control flow (within a function), not across functions.
In general, instead of using Future.then, you should prefer using async/await which will have the compiler generate the callback function with appropriate code transformations for you:
while (true) {
_changeRandomInt()
var documentSnapshot =
await firebaseFirestore.collection("myCollection").doc(_randomInt).get();
if (getFromFirebase(documentSnapshot) == null) {
break;
}
}
Note that performing an asynchronous operation continuously in a loop isn't very efficient, so you probably should consider alternative approaches if possible, however.
I'm wrapping an API that emits events in Observables and currently my datasource code looks something like this, with db.getEventEmitter() returning an EventEmitter.
const Datasource = {
getSomeData() {
return Observable.fromEvent(db.getEventEmitter(), 'value');
}
};
However, to actually use this, I need to both memoize the function and have it return a ReplaySubject, otherwise each subsequent call to getSomeData() would reinitialize the entire sequence and recreate more event emitters or not have any data until the next update, which is undesirable, so my code looks a lot more like this for every function
const someDataCache = null;
const Datasource = {
getSomeData() {
if (someDataCache) { return someDataCache; }
const subject = new ReplaySubject(1);
Observable.fromEvent(db.getEventEmitter(), 'value').subscribe(subject);
someDataCache = subject;
return subject;
}
};
which ends up being quite a lot of boilerplate for just one single function, and becomes more of an issue when there are more parameters.
Is there a better/more elegant design pattern to accomplish this? Basically, I'd like that
Only one event emitter is created.
Callers who call the datasource later get the most recent result.
The event emitters are created when they're needed.
but right now I feel like this pattern is fighting the Observable pattern, resulting a bunch of boilerplate.
As a followup to this question, I ended up commonizing the logic to leverage Observables in this way. publishReplay as cartant mentioned does get me most of the way to what I needed. I've documented what I've learned in this post, with the following tl;dr code:
let first = true
Rx.Observable.create(
observer => {
const callback = data => {
first = false
observer.next(data)
}
const event = first ? 'value' : 'child_changed'
db.ref(path).on(event, callback, error => observer.error(error))
return {event, callback}
},
(handler, {event, callback}) => {
db.ref(path).off(event, callback)
},
)
.map(snapshot => snapshot.val())
.publishReplay(1)
.refCount()
I have two Actions with the same input/output/error types, and I'd like to compose them into a single Action that runs whichever of the two is enabled (with an arbitrary tie-breaker if they both are).
Here's my first, failing, attempt:
let addOrRemove: Action<MyInput, MyOutput, APIRequestError> = Action(enabledIf: add.isEnabled.or(remove.isEnabled)) { input in
if add.isEnabled.value {
return add.apply(input)
} else {
return remove.apply(input)
}
}
This fails because the inner add.apply(input) can't see that I checked add.isEnabled, so it wraps an additional ActionError<> layer around the error type. (This might be legit, as I'm not sure how thread-safe this approach would be, or might be a case of us knowing something the type system doesn't.) The corresponding type error is:
cannot convert return expression of type 'SignalProducer<MyOutput, ActionError<APIRequestError>>' to return type 'SignalProducer<MyOutput, APIRequestError>'
What should I do instead?
Github user #ikesyo provided the following answer on the ReactiveSwift issue I opened to ask the same question:
let producer: SignalProducer<MyOutput, ActionError<APIRequestError>>
if add.isEnabled.value {
producer = add.apply(input)
} else {
producer = remove.apply(input)
}
return producer.flatMapError { error in
switch error {
case .disabled: return .empty
case let .producerFailed(inner): return SignalProducer(error: inner)
}
}
If they show up here I'll happily change the accepted answer to theirs (credit where it belongs).
Warning: If I'm reading this answer correctly, it's not watertight. If add changes from enabled to disabled between the apply() and the start() of the wrapping Action, we'll get "success" (no values, but .completed) instead of the .disabled we should get. That's good enough for my use case, but YMMV.
So, this is the problem I am stuck at for a few weeks.
I am developing an Eclipse plugin which fills in a View with custom values depending on a particular StackFrame selection in the Debug View.
In particular, I want to listen to the stackframe selected and would like to get the underlying IStackFrame object.
However, I have tried more than a dozen things and all of them have failed. So I tried adding DebugContextListener to get the DebugContextEvent and finally the selection. However, the main issue is that ISelection doesn't return the underlying IStackFrame object. It instead returns an object of type AbstractDMVMNode.DMVMContext. I tried getting an adapter but that didn't work out too. I posted this question sometime back also:
Eclipse Plugin Dev- Extracting IStackFrame object from selection in Debug View
Since then, I have tried out many different approaches. I tried adding IDebugEventSetListener (but this failed as it cannot identify stack frame selection in the debug view).
I tried adding an object contribution action but this too was pointless as it ultimately returned me an ISelection which is useless as it only returns me an object of class AbstractDMVMNode.DMVMContext and not IStackframe.
Moreover, I checked out the implementation of the VariablesView source code itself in the org.eclipse.debug.ui plugin. It looks like a few versions back (VariablesView source code in version 3.2), the underlying logic was to use the ISelection and get the IStackFrame. All the other resources on the internet also advocate the same. However, now, this scheme no longer works as ISelection doesn't return you an IStackFrame. Also, the source code for the latest eclipse Debug plugin (which doesn't use this scheme) was not very intuitive for me.
Can anyone tell how I should proceed ? Is hacking the latest Eclipse source code for VariablesView my only option ? This doesn't look like a good design practice and I believe there should be a much more elegant way of doing this.
PS: I have tried all the techniques and all of them return an ISelection. So, if your approach too return the same thing, then it is most likely incorrect.
Edit (Code snippet for trying to adapt the ISelection):
// Following is the listener implemnetation
IDebugContextListener flistener = new IDebugContextListener() {
#Override
public void debugContextChanged(DebugContextEvent event) {
if ((event.getFlags() & DebugContextEvent.ACTIVATED) > 0) {
contextActivated(event.getContext());
}
};
};
// Few things I tried in the contextActivated Method
//Attempt 1 (Getting the Adapter):
private void contextActivated(ISelection context) {
if (context instanceof StructuredSelection) {
Object data = ((StructuredSelection) context).getFirstElement();
if( data instanceof IAdaptable){
System.out.println("check1");
IStackFrame model = (IStackFrame)((IAdaptable)data).getAdapter(IStackFrame.class);
if(model != null){
System.out.println("success" + model.getName());
}
}
}
}
// Attemp2 (Directly getting it from ISelection):
private void contextActivated(ISelection context) {
if (context instanceof StructuredSelection) {
System.out.println("a");
Object data = ((StructuredSelection) context).getFirstElement();
if (data instanceof IStackFrame) {
System.out.println("yes");
} else {
System.out.println("no" + data.getClass().getName());
}
}
// This always execute the else and it prints: org.eclipse.cdt.dsf.ui.viewmodel.datamodel.AbstractDMVMNode.DMVMContext
}
// Attemp3 (Trying to obtain it from the viewer (similiar to object action binding in some ways):
private void contextActivated(ISelection context) {
VariablesView variablesView = (VariablesView) PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage().findView(IDebugUIConstants.ID_VARIABLE_VIEW);
if (variablesView != null) {
Object input = ((TreeViewer) variablesView.getViewer()).getInput();
if(input != null) System.out.println(input.getClass().getName());
if (input instanceof IStackFrame) {
System.out.println("success");
} else if (input instanceof IThread) {
System.out.println("success");
try {
IStackFrame[] stackFrames = ((IThread) input).getStackFrames();
for (IStackFrame iStackFrame : stackFrames) {
printVariables(iStackFrame);
}
} catch (DebugException e) {
e.printStackTrace();
}
}
}
}
While I am building this view to work with both JDT & CDT, I am testing it out on the C project. So, this might be the reason why I always get the returned object type as AbstractDMVMNode.DMVMContext. Should my implementation be different to handle both these cases ? I believe I should be building a generic view. Also, if AbstractDMVMNode.DMVMContext is CDT specific, I should I go about implementing it for the CDT case?