I am currently using silverlight to build a control for a CRM form.
There are quite a few asynchronous calls being made where I am retrieving various sets
of data. The problem I am facing however is sometimes the calls are made in a random order
and I need to retrieve the data in a particular order for data binding reasons.
Any idea?
Basically I have 3 Methods -
Retrieve Accounts
Retrieve Opporunities
Retrieve Leads
Each have call backs but I want each to respond with results from callback before moving to the next.
Make the calls synchronous, or
in each call back, invoke the next call
Related
Can any one suggests the best way to page through an API in Mule 4? The examples I saw used a choice with a flow reference to call the flow again in a loop. This API doesn't return the total number of records or pages so need to loop through each page until it returns an empty payload.
But if I call the same flow recursively, its throwing too many child context error.
What is the ideal way to handle this scenario?
I faced same kind of scenario recently. I have done a recursive call using another flow to call the parent flow. If you use a flow reference from the same flow it will not allow you to do so.
In the child flow, I have incremented the next start index as well.
If you are looking for paging from the API level, you can accept the start index and the Page size as the two parameters. This call can go until the number of records < page size OR the API returns 0 records.
I'm developing an application in which race conditions could occur when calling the Google Sheets API. This can happen due to multiple separate users executing the same use case with significantly different parameters. All requests from these users are handled separately and asynchronously.
For simplicity's sake I'll refer to these calls as call A and call B. Both being completely different and asynchronous requests. The values written in both calls will be completely different, hence the output in the read calls will return completely different values.
Normal situation:
Write call A
Read call A
Write call B
Read call B
Simultaneous calls:
Write call A
Write call B
Read call A (this now unintentionally fetches the result written by call B)
Read call B
When both actions are executed simultaneously a condition can occur that the write of call B could race the read of call A. This results in malformed output in the read of call A as the parameters of B are used.
Obviously I should improve the applications design by using a queue mechanism, but I'm hoping multiple users have bumped into this problem and that the API has a solution to this issue.
I've been nosing around in the API documentation and couldn't find support for certain cases other than having multiple duplicate sheets and randomising the IDs within my application.
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 have an action which will invoke a service (not database)to get some data for display,and i want to do paging on these data.however,every time a second page is clicked,it will invoke this action and of course invoke the service again,actually when i click the first page link,it already generate the whole data including what the second page needs. i just want to invoke the service once and get all the data,and later when paging,i don't need to invoke the service again,how can i deal with that?hope someone could give me a hint~
There are several ways to address this. If it's practical and a limited amount of data, it's ok to return the entire data set in the first request.
If that's your case I would consider returning a pure JSON object when you load the page initially. You can then deserialize this into a JS object variable on the web page that you can perform your paging operations against. This is an example of client side paging where all the data exists client side.
Another approach is to do Ajax based paging where you request the data for the next page as needed. I would still recommend returning JSON in this scenario as well.
The two approaches differ in that the first one returns all the data upfront, whereas the second one only returns what you need to render any given page.
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.