Could someone please explain how Fork from Elsa Workflow works?
I have set up HTTP Endpoint. After that I send HTTP Request and I get HTTP Response in JSON format.
I want to set condition on that response (for example name='John') so that I could display only that row from database.
What Elsa activity should I use? Is Fork activity correct choice or other?
Fork
The Fork activity simply forks workflow execution into multiple branches. When you add this activity, you specify a list of one or more branch names. These branch names will be scheduled as activity outcomes.
For example, if you add a Fork activity with branches Do Some Request and Timeout, the Fork activity will show these branches as outcomes.
When the Fork activity executes, both branches will execute. This enables scenarios where you for example want to wait for some user input or some other job to finish, but not indefinitely: you have a second branch that waits for a timeout event using e.g. the Timer activity.
A sample workflow that describes the usage of the Fork activity in a similar scenario can be found here.
That describes the use case of the Fork activity. But you will want to use the If activity instead.
If
Going back to your use case with the HTTP Request activity and setting a condition, what you want to use instead of Fork is the If activity.
When you connect an If activity to HTTP Request, you will be able to write a JS expression that must evaluate to true or false.
For example, let's say your Send HTTP Request activity performs a GET request on https://reqres.in/api/users/2
Make sure that the Read Content checkbox is ticked.
Also make sure to give your Send HTTP Request activity a name. For example, SendHttpRequest1.
With that in place, you can now write the following JS expression in the Condition field of the If activity:
activities.SendHttpRequest1.ResponseContent().data.first_name == 'Janet'
Note that activities.SendHttpRequest1.ResponseContent() returns an ExpandoObject that represents the received JSON response from the demo API endpoint I used in my example.
Related
My api has a job resource which contains a state attribute. The state of a job can be "scheduled", "processing" or "done". The jobs state is determined server-side. When a jobs state is "processing" and ETL process is run server-side.
I want the client to be able to triggering an action like "start" which would set the jobs state to "processing" or trigger a "stop" action which would reset the jobs state to "scheduled".
My question here is how should I handle these "custom" action in REST?
I see two possible approaches:
I could create two new endpoint
POST /job/:id/start
POST /job/:id/stop.
I could create one endpoint which take an action query-param.
POST /job/:id?action=start
POST /job/:id?action=stop
I'm not sure which is considered more RESTful, if either?
Additional, I'm not sure what the response code should be? I'm guessing one of the following: 200 (OK), 202 (Accepted), 204 (No content) but not sure which be best. For example, if the api returned a 200 response should the response body contain the job resource with the updated state? Or, should the api just return 204 no content?
REST does not care about business logic, only about resources - so the most RESTful approach would be a PUT to /job/:id where the document sent will contain the new status.
Although technically the "correct" solution (don't tell Roy Fielding) I rather prefer explicit "actions" like /job/:id/start because it allows my resource to return links to those actions to tell the client if the appropriate action is possible or not (a GET to a "stopped" job would contain a link to start that job for example).
On the basis of HTTP status codes I usually return a 204 when I am not interested in the result although in your case a 200 with the updated resource would be correct - only when you e. g. "start" an already started job a 304 Not Modified would be correct from the view of the client as the state wouldn't have changed.
I would chose 202 Accepted if starting a job has no direct effect on the resource because the job will be e. g. queued and only updated later so that the client knows that an async action has been started.
I have to create a table, such that it sends Http Request with a parameter (first column value) for each row in the table and shows processing status for that request.
There is same backend process for each row with a column value passed as a parameter.
On completion of the request for the first row, the status column in the table should show 'Success' and then the request for the second record should be sent.
The request should be sent synchronously as there is moderately heavy backend process attached i.e. on completion of the previous request only next request has to be sent.
I have to achieve this using Angular 5 and DotNet Core 2.0.
Please let me know if there is a feature already available for doing such a thing in Angular 5 and .net Core in an optimized way. I have heard of ReactiveX but I am not able to figure out the best way to achieve this as Reactivex is for asynchronous programming.
Any suggestions or similar examples on this would be helpful.
Thanks
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 uploading multiple files using javascript.
After I upload the files, I need to run several processing functions.
Because of the processing time that is required, I need a UI on the front telling the user the estimated time left of the entire process.
Basically I have 3 functions:
/upload - this is an endpoint for uploading the files
/generate/metadata - this is the next endpoint that should be triggered after /upload
/process - this is the last endpoint. SHould be triggered after /generate/metadata
This is how I expect the screen to look like basically.
Information such as percentage remaining and time left should be displayed.
However, I am unsure whether to allow server to supply the information or I do a hackish estimate solely using javascript.
I would also need to update the screen like telling the user messages such as
"currently uploading"
if I am at function 1.
"Generating metadata" if I am at function 2.
"Processing ..." if I am at function 3.
Function 2 only occurs after the successful completion of 1.
Function 3 only occurs after the successful completion of 2.
I am already using q.js promises to handle some parts of this, but the code has gotten scarily messy.
I recently come across Backbone and it allows structured ways to handle single page app behavior which is what I wanted.
I have no problems with the server-side returning back json responses for success or failure of the endpoints.
I was wondering what would be a good way to implement this function using Backbone.js
You can use a "progress" file or DB entry which stores the state of the backend process. Have your backend process periodically update this file. For example, write this to the file:
{"status": "Generating metadata", "time": "3 mins left"}
After the user submits the files have the frontend start pinging a backend progress function using a simple ajax call and setTimeout. the progress function will simply open this file, grab the JSON-formatted status info, and then update the frontend progress bar.
You'll probably want the ajax call to be attached to your model(s). Have your frontend view watch for changes to the status and update accordingly (e.g. a progress bar).
Long Polling request:
Polling request for updating Backbone Models/Views
Basically when you upload a File you will assign a "FileModel" to every given file. The FileModel will start a long polling request every N seconds, until get the status "complete".
I'm creating a 50 users load test on a JSF web application.
I record a scenario using JMeter proxy for one user who logs in, does some db operations and logs out. After recording the scenario, the recorded test contains http requests and data that particularly belongs to the user used while scenario recording.
At the time of running the test for 50 unique virtual users, the recorded test sends http requests and data which was in the recorded scenario. But in our application, the http requests and data vary depending upon the user. So how do I handle such situations in JMeter when it comes to methods being called depending upon the existence or non-existence of data for a user after logging in?
To be precise how would I make changes in my Test plan to manage dynamic urls and dynamic data for each virtual user?
Latest versions of JMeter allow you to write the whole parameters (raw data) from scratch, so you could use variables in this field.
To achieve dynamic URLs use a Regular Expression Extractor (Post-Processor) on a prior request that define what request will be sent and use the variable in HTTP Request's path field.
If you know what request each type of users will send you could use If Controllers and test a thread variable, created by a previous Regular Expression Extractor, and inside each controller add the specific request.
If the subsequent request for each user is defined by the server, using redirection, just check "Follow Redirection" field.
See JMeter Wiki for more examples on how to do this.