How can I access the current context from within a message mutator?
I also need to have access to the saga data.
I want to pass certain data transparently from both the sender and implementers (handlers). This data will be set in the outgoing headers. Depending on the situation, if the handler is of type Saga, I want to set some of these properties into the saga data.
Later when a call "ReplyToOriginator" is detected, I want to grab the values from saga and set it back into the headers of the reply message.
So how can I do this from within the message mutator?
All the examples I have seen so far seems to indicate that it has access only to the message and not context.
Related
I have a subroutine in my Controller
<HttpPost>
Sub Index(Id, varLotsOfData)
'Point B.
'By the time it gets here - all the data has been accepted by server.
What I would like to do it capture the Id of the inbound POST and mark, for example, a database record to say "Id xx is receiving data"
The POST receive can take a long time as there is lots of data.
When execution gets to point B I can mark the record "All data received".
Where can I place this type of "pre-POST completed" code?
I should add - we are receiving the POST data from clients that we do not control - that is, it is most likely a client's server sending the data - not a webbrowser client that we have served up from our webserver.
UPDATE: This is looking more complex than I had imagined.
I'm thinking that a possible solution would be to inspect the worker processes in IIS programatically. Via the IIS Manager you can do this for example - How to use IIS Manager to get Worker Processes (w3wp.exe) details information ?
From your description, you want to display on the client page that the method is executing and you can show also a loading gif, and when the execution completed, you will show a message to the user that the execution is completed.
The answer is simply: use SignalR
here you can find some references
Getting started with signalR 1.x and Mvc4
Creating your first SignalR hub MVC project
Hope this will help you
If I understand your goal correctly, it sounds like HttpRequest.GetBufferlessInputStream might be worth a look. It allows you to begin acting on incoming post data immediately and in "pieces" rather than waiting until the entire post has been received.
An excerpt from Microsoft's documentation:
...provides an alternative to using the InputStream propertywhich waits until the whole request has been received. In contrast, the GetBufferlessInputStream method returns the Stream object immediately. You can use the method to begin processing the entity body before the complete contents of the body have been received and asynchronously read the request entity in chunks. This method can be useful if the request is uploading a large file and you want to begin accessing the file contents before the upload is finished.
So you could grab the beginning of the post, and provided your client-facing page sends the ID towards the beginning of its transmission, you may be able to pull that out. Of course, this would be reading raw byte data which would need to be decoded so you could grab the inbound post's ID. There's also a buffered one that will allow the stream to be read in pieces but will also build a complete request object for processing once it has been completely received.
Create a custom action filter,
Action Filters for executing filtering logic either before or after an action method is called. Action Filters are custom attributes that provide declarative means to add pre-action and post-action behavior to the controller's action methods.
Specifically you'll want to look at the
OnActionExecuted – This method is called after a controller action is executed.
Here are a couple of links:
http://www.infragistics.com/community/blogs/dhananjay_kumar/archive/2016/03/04/how-to-create-a-custom-action-filter-in-asp-net-mvc.aspx
http://www.asp.net/mvc/overview/older-versions-1/controllers-and-routing/understanding-action-filters-vb
Here is a lab, but I think it's C#
http://www.asp.net/mvc/overview/older-versions/hands-on-labs/aspnet-mvc-4-custom-action-filters
I am attempting to get the parameters for a POST request sent via the AFNetworking pod. However, I can't seem to get them. I am looping through the active operations with the below:
for(AFHTTPRequestOperation* operation in manager.operationQueue.operations){
NSLog(#"%#",operation.request.URL.path);
}
However, I can't get the parameters. I've tried using operation.request.URL.parameterString, but since it is POST, the string is null. Anyone know how to get these? I'd like to collect them so that I can cancel requests that are specific to the path and parameters sent, ensuring I'll get down to just the single request I need to cancel.
I ended up going about this a different way. I created a class that handled all the AFNetworking path calls. In this class is a dictionary which stored an integer id for the call and the operation. As the operations complete or fail, they are removed. The integer id is passed back to the calling object, allowing for unique access for canceling requests or polling.
I have an endpoint which receives messages and creates a saga in order to be able to response to that corresponding message at a later point in time. The message contains some xml document and this xml doc will be validated within this message handler. If we catch some validation errors, we create a message response (no saga involved) to inform the originating endpoint that something with the xml doc was wrong. In the case of a validation error, the saga is not stored as expected and as required. But I still want to reply to the originating endpoint. The problem is, that nservicebus also does a rollback on the reply.
Is there a way to go? I tried to wrap the reply into a new transaction scope, but this did not work:
using (var scope = new TransactionScope(TransactionScopeOption.RequiresNew))
{
this.bus.Reply(message);
scope.Complete();
}
Any advice? Thanks in advance
Additional Information:
The orginal problem was that I did not throw (or rethrow) any exception but replying
to the originator in the catch section (I know its bad design).
The Saga is stored with a unique attribute applied on a id, which comes from the originating endpoint. And since I did not throw or pass any exception in the reply case (validation error occured), nservicebus always stored the saga. If the originating endpoint corrects the xml so that this is valid and resends a message (with the same id) nservicebus tries to store a new saga with the same id (causes concurrency exception on ravenDB because the saga with that unique property already exists). As a quick fix, I want to change the unique property and use instead the message id as the unique prop. In that case, I am sure that the message id is always unique and a saga concurrency exception could not happen again. Do you know if that causes any side effects?
You may be able to leverage the message handler pipeline. The first handler in your pipeline could do the validation and any response if necessary. During the validation, do not throw an exception, just reply. The second handler could initiate the Saga and set the state to be "Invalid" or something like that. My assumption is that you will get another request with valid data and then you will follow the "normal" process and set the state to "Valid" and continue on.
Some of my NServiceBus commands will need to track who issued the command and when. I'm very unsure as to the recommended way to implement this:
Should I create a base class MessageBase, add public Dictionary<string, string> Headers;, and implement IMutateOutgoingMessages?
Should it be added to the MessageContext? If so, how do I ensure the Bus adds it before every message (which needs the headers) is sent?
Is it already done and I just don't know how to access it? (It looks like the user is in the raw MSMQ message...)
NServiceBus already gives you the time the message was sent using the "NServiceBus.TimeSent" header.
Use the builtin NServiceBus headers dictionary and skip the MessageBase
Attaching user id is best done in a outgoing message mutator. Just grab the ID from eg the HttpContext and add it as a header.
http://support.nservicebus.com/customer/portal/articles/860492
To get the time (in your handler/saga):
Bus.CurrentMessageContext.TimeSent
I've spend days trying to find a solution the problem i'm going to try to describe, i've googled alot and even looked at the .NET 4 reference source for SendReply and InternalSendReply activity. But until now i'm stuck.
To make the life of our end customers simpler i want to replace the Receive and SendReply activities with custom activites and use bookmarks instead.
I'm implementing a central webservice which can route to a correct workflow instance, that workflow modifies the bookmark value and finaly it creates a new bookmark while returning the modified bookmark value. It's rather complex already with a WorkflowServiceHostFactory which adds Behaviours and Attach a DataContractResolver to the endpoint.
The endpoint is derived from WorkflowHostingEndpoint which resolves a bookmark created in a custom activity (instead of a receive). And i want another activity instead of a sendreply. Those 2 should correlate and the custom sendreply does send a response on the open channel through the endpoint while creating a new bookmark.
The problem is that i didn't find a way yet to access the endpoint responseContext from within my custom send activity. On the other side, at the workflowcreating endpoint side, it seems that i'm not able to be notified whenever the workflow becomes Idle and as well i don't seem to be able to access the WorkflowExtensions from the host. i'm missing something?
A possible solution i've in mind might be not using a WorkflowServiceHost, but then i loose alot of AppFabric functionaly.
The workflowapplication in platform update 1 has some extension methods called RunEpisode with an overload Func called idleEventCallback. There it's possible to hook into the OnIdle and get a workflowextension to get the object to send back as response.
To answer my own question, i ended up in a workaround using the servicebroker functionality of sql server. The SqlDependency class where the workflow listens for the event to be fired whenever the workflow reach the activity that creates a new bookmark in another state.