private void Subscribe()
{
EventSystem.Subscribe<User, LoadEventArgs>(GetInfo, EventPhases.Initiated);
}
public void GetInfo(User user, LoadEventArgs args, EventPhases phase)
{
TcmUri id = user.Id;
string name = user.Title;
Console.WriteLine(id.ToString());
Console.WriteLine(name);
}
I wrote above code and add the assembly in config file in Tridion server but no console window is coming on login of a user
The event you were initially subscribing to is the processed phase of any identifiable object with any of its actions, that will trigger basically on every transaction happening in the SDL Tridion CMS, so it won't give you any indication of when a user logs in (it's basically everything which happens all the time).
Probably one of the first things which is happening after a user logs in, is that its user info and application data is read. So what you should try is something along the lines of:
private void Subscribe()
{
EventSystem.Subscribe<User, LoadEventArgs>(GetInfo, EventPhases.Initiated);
}
public void GetInfo(User user, LoadEventArgs args, EventPhases phase)
{
TcmUri id = user.Id;
string name = user.Title;
}
But do keep in mind that this will also be triggered by other actions, things like viewing history, checking publish transactions and possibly a lot more. I don't know how you can distinguish this action to be part of a user login, since there isn't an event triggered specifically for that.
You might want to check out if you can find anything specific for a login in the LoadEventArgs for instance in its ContextVariables, EventStack, FormerLoadState or LoadFlags.
Edit:
Please note that the Event System is running inside the SDL Tridion core, so you won't ever see a console window popup from anywhere. If you want to log information, you can include the following using statement:
using Tridion.Logging;
After adding a reference to the Tridion.Logging.dll which you can find in your ..\Tridion\bin\client directory. Then you can use the following logging statement in your code:
Logger.Write("message", "name", LoggingCategory.General, TraceEventType.Information);
Which you will find back in your Tridion Event log (provided you have set the logging level to show information messages too).
But probably the best option here is to just debug your event system, so you can directly inspect your object when the event is triggered. Here you can find a nice blog article about how to setup debugging of your event system.
If you want to get the TCM URI of the current user, you can do so in a number of ways.
I would recommend one of these:
Using the Core Service, call GetCurrentUser and read the Id property.
Using TOM.NET, read the User.Id property of the current Session.
It looks like you want #2 in this case as your code is in the event system.
Related
I have a dashboard with a list of items and a finite number of users. I want to show "an item is being edited" near said item to avoid simultaneous edits and overwrites of data.
This seems to me like updating a flag in the database and relatively simple signalr implementation with the javascript simply adding/removing a css class.
I have seen this:
Prevent multiple people from editing the same form
which describes a method with posting every X minutes and clearing the flag from the database when there are no more update messages from the user.
The issue is:
I was wondering if there was a signalr method (like disconnect; i know it exists but I don't know if it fits this scenario) to do that elegantly rather than running a timer function. If so, is it possible for the server to miss the event and permanently leave the flagged as "editing" when it is not?
you could implement a hub for this, here is a example:
public class ItemAccessHub : Hub
{
public override Task OnConnectedAsync()
{
// your logic to lock the object, set a state in the db
return base.OnConnectedAsync();
}
public override Task OnDisconnectedAsync(Exception exception)
{
// your logic to unlock the object
return base.OnDisconnectedAsync(exception);
}
}
to get information from the query you can access the HttpContext:
Context.GetHttpContext().Request.Query.TryGetValue("item-id", out var itemId)
so you could start a connection when the user is accessing the form and send the id of the item in the query:
/hub/itemAccess?item-id=ITEM_ID
and when the user closes the form then disconnect the connection.
with this method the item is also unlocked when the user loses his network connection.
the on disconnect method is allays invoked when a client disconnects, so you can do your clean up in this method.
in this hub you can than also implement the update function
i hope this is what you are looking for
In Axon, Command Interceptors seem to intercept any and every command. For permission checking, I need to base my decision on the type of command to see whether it is allowed in the current context.
#Override
public BiFunction<Integer, CommandMessage<?>, CommandMessage<?>> handle(List<? extends CommandMessage<?>> messages) {
return (index, command) -> {
// Check permissions
return command;
};
}
Usually I would prefer to register an interceptor per command type and handle the permission checks in dedicated objects. How would I do it with Axon? Will I need to have a load of instanceof if-statements in a single interceptor? Does anyone have a good example of permission checking with Axon?
At this point (Axon 4.0) the framework does not allow you the option to register DispatchInterceptors per command payload type directly. So what you're suggesting to do, the if-blocks/switch-statements, is the best thing you could do at this point.
Although I am not certain how fine grained your permission checks are, what you could do is have some form of permission annotation on the commands, with a specific value/enum you need to set on it. That way you do not have to tie in your payload type into the dispatcher directly, but could just check if the annotation exists and if so, check it's value for the kind of permission check which should be performed on it.
That would very likely result in a far smaller if-block/switch-statement than checking per payload type.
I have read multiple times the documentation on the website. I am reading again and again the same articles and I cannot understand what they are trying to achieve with sagas. Besides, there are almost no resources in internet related to this subject.
But I am completely stuck trying to understand the purpose and benefit of defining so called sagas. I understand handlers (IHandleMessages) - these are interceptors. But I can't understand what Saga is for. The language in the documentation assumes that I am supposed to know something special to grasp that idea, but I dont.
Can someone explain to me in simple words, hopefully with real-life example a situation where I must or should define Saga, and what is the benefit of doing so? I have created an app with multiple endpoints and Saga definition as shown in samples, it works (I guess) but I don't understand what these sagas were defined for... In many samples they use RequestTimeout() method in Saga class. Why, why would anyone want to cause a timeout intentionally? I dont want to put any code fragments here, because its unrelated, I need to understand why I would want to use "Sagas" whatever that means?
Thank you.
NServiceBus Saga is a variant of a Process Manager described in the Enterprise Integration Patterns book.
To understand when to use Saga, one has to need it. Let's assume you're using regular message handlers only to implement new user registration process. At some point in time, you discover that only 40% of the brand-new registrants confirm their email address and becoming active user accounts. There are two things you'd like to address.
Remind new registrants to confirm their email after 24 hours after registration by sending a reminder.
Remove registrant info (email for example) from the data store to be compliant with GDPR within 48 hours.
Now how do you do that with a regular message handler? A handler would receive the initial request (first message, m1) to kick off registration by generating an email with a confirmation link and that's it. Once the handler is done, it's done for good. But your process is not finished. It's a long-running logical process that has to span 48 hours before completed. It's no longer just a single message processing, but a workflow at this point. A workflow with multiple checkpoints. Similar to a state machine. To move from one state to another, a certain condition has to be fulfilled. In case of NServiceBus, those would be messages. A message to send a reminder after 24 hours (let's call it m2) is not going to be triggered by any user action. It's a "system" message. A timed message that should be kicked off automatically. So is with the message to instruct the system to remove registrant information if validation link was not activated. The theme can be observed: need to schedule messages in the future to re-hydrate the workflow and continue from the state it was left last time.
That's what timeouts are. Those are requests to re-hydrate/continue saga/workflow from the point it was left last time at a certain point in time - minutes, hours, days, months, years.
This is what this kind of workflow would look like as a saga (oversimplified and doesn't take into consideration all the edge cases).
class RegistrationWorkflow :
Saga<WorkflowState>,
IAmStartedByMessages<RegisterUser>,
IHandleMessages<ActivationReceived>,
IHandleTimeouts<NoResponseFor24Hours>,
IHandleTimeouts<NoResponseFor48Hours>
{
protected override void ConfigureHowToFindSaga(SagaPropertyMapper<WorkflowState> mapper)
{
// omitted for simplicity, see message correlation
// https://docs.particular.net/nservicebus/sagas/message-correlation
}
public async Task Handle(RegisterUser message, IMessageHandlerContext context)
{
Data.RegistrationId = message.RegistrationEmail;
await RequestTimeout<NoResponseFor24Hours>(context, TimeSpan.FromHours(24));
}
public async Task Handle(ActivationReceived message, IMessageHandlerContext context)
{
Data.ConfirmationReceived = true;
// email was confirmed and account was activated
await context.Send(new PromoteCandidateToUser
{
CandidateEmail = Data.RegistrationEmail
});
MarkAsComplete()
}
public async Task Timeout(NoResponseFor24Hours timeout, IMessageHandlerContext context)
{
if (Data.ConfirmationReceived)
{
return;
}
await context.Send(new SendReminderEmailToActivateAccount { Email = Data.RegistrationEmail });
await RequestTimeout(context, TimeSpan.FromHours(24), new NoResponseFor48Hours());
}
public async Task Timeout(NoResponseFor48Hours timeout, IMessageHandlerContext context)
{
if (Data.ConfirmationReceived)
{
return;
}
context.Send(new CleanupRegistrationInformationForGDPRCompliancy
{
RegistrationEmail = Data.RegistrationEmail
});
MarkAsComplete();
}
}
Since this is a state machine, the state is persisted between Saga invocations. Invocation would be caused either by a message a saga can handle (RegisterUser and ActivationReceived) or by timeouts that are due (NoResponseFor24Hours and NoResponseFor48Hours). For this specific saga, the state is defined by the following POCO:
class WorkflowState : ContainSagaData
{
public string RegistrationEmail { get; set; }
public bool ConfirmationReceived { get; set; }
}
Timeouts are nothing but plain IMessages that get deferred. The timeouts used in this samples would be
class NoResponseFor24Hours : IMessage {}
class NoResponseFor48Hours : IMessage {}
Hope this clarifies the idea of Sagas in general, what Timeouts are and how they are used. I did not go into Message Correlation, Saga Concurrency, and some other details as those can be found at the documentation site you've referred to. Which bring us to the next point.
I have read multiple times the documentation on their website. It is absolutely terrible. I am reading again and again the same articles and I cannot comprehend what they are trying to achieve.
The site has a feedback mechanism you should absolutely provide.
Besides there almost no resources in internet related to this subject.
Hope to see you posting a blog (or a series of posts) on this topic. By doing so you'll have a positive contribution.
Full disclaimer: I work on NServiceBus
In the apache brooklyn web interface we would like to display some content for the sytsem managers. The content is too long to be served as a simple sensor value.
Our idea was to create a task and write the content into the output stream of the task, and then offer the REST based URL to the managers like this:
/v1/activities/{task}/stream/stdout (Of course the link masked with some nice text)
The stream and task is created like this:
LOG.info("{} Creating Activity for ClusterReport Feed", this);
activity = Tasks.builder().
displayName("clusterReportFeed").
description("Output for the Cluster Report Feed").
body(new Runnable() {
#Override
public void run() {
//DO NOTHING
}
}).
parallel(true).
build();
LOG.info("{} Task Created with Id: " + activity.getId(), this);
Entities.submit(server, activity).getUnchecked();
The task seems to be created and the interraction works perfectly fine.
However when I want to access the tasks output stream from my browser using a prepared URL I get the error that the task does not exist.
Our idea is that we are not in the right Management/Execution Context. The Web page is running in an other context compared to the entities and their sensors. How can we put a task so that it's visible for the web consoles context also.
Is it possible to write the content into a file and then offer it for download via Jetty(brooklyns web server)? That would be a much simpler way.
Many tasks in Brooklyn default to being transient - i.e. they are deleted shortly after they complete (things like effector invocations are by default non-transient).
You can mark your task as non-transient using the code below in your use of the task builder:
.tag(BrooklynTaskTags.NON_TRANSIENT_TASK_TAG)
However, note that (as of Brooklyn version 0.9.0) tasks are kept in-memory using soft references. This means the stdout of the task will likely be lost at some point in the future, when that memory is needed for other in-memory objects.
For your use-case, would it make sense to have this as an effector result perhaps?
Or could you write to an object store such as S3 instead? The S3-approach would seem best to me.
For writing it to a file, care must be taken when used with Brooklyn high-availability. Would you write to a shared volume?
If you do write to a file, then you'd need to provide a web-extension so that people can access the contents of that file. As of Brooklyn 0.9.0, you can add your own WARs in code when calling BrooklynLauncher (which calls BrooklynWebServer).
I have created a simple state-machine workflow in youtrack to reflect our process. It uses three State values (Submitted, In Progress, Fixed) and allows to move through them sequentially.
Is it possible to restrict certain state changes for specific roles? For example role Reporter should only be able to create issue and move from 'Fixed' to 'In Progress' if something is wrong.
UPDATE:
An even better way to do this task is the following right inside the Statemachine:
initial state Submitted {
on Approve[always] do {
assert loggedInUser.hasRole("Project Admin"): "Only Project Admins can Approve tasks.";
} transit to Open
}
OLD ANSWER:
Straighforward way (inside the Statemachine itself):
initial state Submitted {
on Approve[loggedInUser.hasRole("Project Admin")] do {<define statements>} transit to Open
}
Althought it will work, it will fail silently, so user will not know why does it not work.
A much better approach will look like the following (for this you will have to create Stateless Rule):
when State.oldValue == {Submitted} && State.becomes({Open}) {
assert loggedInUser.hasRole("Project Admin"): "Only Project Admins can Approve tasks.";
}
In this case user will get an error message that you specify.
Remember to delete the condition in the Statemachine, since it is checked earlier and you will not have any error messages as assertion will not run at all.
A pretty old question, but I'll try to answer.
You can specify a guard expression that will be invoked upon transition to/from a specific state. In this expression you can validate user permissions.