While performing transactions on sawtooth node from client(using go sdk) the apply method in handler is being called multiple times.response after submitting invalid transaction
Related
Accessing the local filesystem a la: https://developer.mozilla.org/en-US/docs/Web/API/FileSystemFileHandle
If I inline all my code for the show(Open|Save)FilePicker API logic directly in my button event closure or call plain fn's then things work ok. However, if I define a class w/helper methods and call those from my event-handler, and those helpers call the file pickers, then I get this error:
Uncaught DOMException: Failed to execute 'showOpenFilePicker' on 'Window': Must be handling a user gesture to show a file picker.
I assume the the security system is looking at this to establish the gesture context - is there a way to re-establish this context with code running in my class?
Turns out the class methods were a red herring -- the issue has to do with async code and promises -- this is what looses the context and causes the error.
You need to make any calls to the FS without any promise chaining.
Is it possible to throw an exception in a Logic App?
Specifically, I'm trying to throw an exception inside of a scope. Then in the run after of the scope I'd check if it failed and inspect it for errors. I tried using a terminate inside of a scope, but that terminates the entire logic app run.
As an updated solution we can use Terminate control, Terminate control has 3 status: Failed, Canceled, and Succeeded.
Quick Answer (TL;DR)
Problem: MSFT Azure logic app throwing exceptions
Workaround: Use logic app Scope element to simulate throwing exceptions
Create a scope element to use as your "try-catch" block
Force the scope element to fail with an invalid command to simulate an exception
Allow the scope element to fail naturally and that will count as an exception too
Detailed Answer
Context
MSFT Azure logic app workflows
live version as of 2020-06-14
Problem
Scenario: Developer wishes to throw an exception or use try-catch semantics in a logic app
Solution
As of this writing, the live version of the product does not support this feature. There is a workaround.
Workaround
Use logic app scope element
add a conditional statement inside the scope element
If the conditional statement meets the failure condition, force an exception with a deliberately invalid command
for example create a variable assignment with the value int('__ERROR__')
If the conditional statement does not meet the failure condition, do nothing
The rest of the logic app consists of two paths
The first path runs on the success of the scope element
The second path runs on the failure of the scope element (failed, skipped, timed out)
Example
Create a scope element as a "try-catch" block
Create a variable compose element with an invalid command
int('__ERROR__') ## this will cause the enclosing scope to fail
## the string __ERROR__ cannot be cast to integer
Respond to exit status of the Scope element enclosing your exception
See also
related SO answer about forcing exceptions https://stackoverflow.com/a/61101945/42223
No, there is no Action or Connector directly analogous to something like a throw in C#.
The closest you can get right now would be to do something like use another LogicApp instead of a scope from which you can return a specific status code.
It seems like there still is no option for this inside Logic App or its little brother Power Automate / Microsoft Flow.
The way I have come up with and have used in some flows, is I simply add an action for something I know for a fact will fail.
The simplest (and probably the cheapest as the built-in actions cost less in Logic Apps, even if we are talking fractions of a dollar here either way) is probably to initialize a variable, e.g. called ThrowException with type of integer.
Then a "Set variable" action is added wherever I want my flow to fail, where I set the value (remember it is of type integer) to any string expression. I simply use the expression string('Exception').
Simple example screenshot
Since the value is set via an expression this is still a valid template, but will fail upon runtime when the value is actually being set.
After this, simply use parallel branches, with appropriate Run After settings, as usual.
I have created a SSIS package for migrating data from one sql server database to another. The tasks are created in a sequence container.
I have created events in the event handler and added the send mail task for sending email and getting the following error. I get this error even when I try to evaluate the expression in the expression builder. Please note that I am getting the error on the onTaskFailed event handler. I think the system error variables are not accessible in that event. Do I really need that event handler
I can see the variable in the collection. Not sure of how the scope affects it.
This is definitely a scoping issue. The system variable 'ErrorDescription' is only avialable at 'OnError' event handler and can't be used in 'TaskFailed' event handler. As to the question of if you need it or not, that is something your business logic should dictate. I would suggest to move your code to 'OnError' event handler.
When i use IMvxmessenger i get an exception that says An exception of type 'System.Exception' occurred in mscorlib.dll but was not handled in user code WinRT information: The application called an interface that was marshalled for a different thread. Additional information: The application called an interface that was marshalled for a different thread.If there is a handler for this exception, the program may be safely continued.
From the information in your question it's very hard to add much real advice.
Clearly you are using a message from the messenger to access something that is thread critical.
MvvmCross and WinRT both provide ways to marshal method calls on to specific threads - e.g. there are several different Subscribe methods provided by the messenger to allow you to specify context - see https://github.com/MvvmCross/MvvmCross/wiki/MvvmCross-plugins#messenger
The three different options for subscribing for messages differ only in terms of which thread messages will be passed back on:
Subscribe - messages will be passed directly on the Publish thread. These subscriptions have the lowest processing overhead - messages will always be received synchronously whenever they are published. You should use this type of subscription if you already know which type of thread the Publish will be called on and if you have a good understanding on the resource and UI usage of your message handler.
SubscribeOnMainThread - any message published on a background thread will be marshalled to the main UI thread. This type of subscription is ideal if your message handler needs to perform some resource-unintensive task which involves interacting with the UI.
SubscribeOnThreadPoolThread - messages will always be queued for thread pool processing. This always involves an asynchonous post - even if the message is published on an existing ThreadPool thread. This type of subscription is ideal if your message handler needs to perform some resource-intensive task as it won't block the UI, nor the message publisher.
Let suppose I create a class, and in this class I declare a method that will run a loop.
My question is what will be behavior of loop, if I dispose the object of class and condition of loop is yet true - will loop execute or terminate.
Usually the object (variable) is managed by a single thread. So you may not be able dispose of easily because the thread is still running in the loop. If you mult-thread and you call in a method that modifies this variable (your object) on the a different thread you may crash your program. If your loop in a UI thread which has a message pump (sta thread) and you call a method directly from another thread then you app will crash as this is not allowed.
All in all what do you want to do ? Mark Byers's condition "The code keeps running" is the most possiable outcome of this I think. But you have a bug either way - don't attempt to drive a car and then just jump out of it without stopping.