will appreciate any pointers here. This scenario may sound a bit weird:
I am trying to write a program that consume webservices that user define, and that my program do not know in advance.
For example, my program allow users to set/define all the webservices that they have in their network, into my database.
My program will then show a list of all the webservices that users have defined, and with a click, my program will call THAT webservice (with the parameters that use can key in) and then my program will show the result (string).
Problem is that at design time, I have no idea what are the webservices and the parameters and response. So, I need to dynamically create some sort of a stub that can consume these webservices without having to Add-Reference into my project in advance.
Will appreciate any pointers here.
Sounds like you're trying to build your own SOAP_UI here :) (excellent tool for testing purpose on Webservices) , correct ?
I guess you'd want to play with wsdl.exe.
Related
I have ASP.NET 2010 (VB.NET) web-service having a method "Method1".
I need to invoke that method from Windows application (VB.NET 2010) without waiting for the method to end execution, also do not need to get the return value of the method. Just need to invoke it and that's all.
What is the best way to do that?
If you edit your question giving more information about your needs, maybe some code that you're pretending to use, it should be easy to help you.
So, without that information I can assume that maybe investing about asynchronous methods should be helpful for you. It's not just about put async keyword...
You can find more information from here:
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/5179579a-492b-4aad-babe-fdef854b68b3/c-50-calling-a-method-without-requiring-to-wait-for-it-to-finish-nor-its-results?forum=csharpgeneral
Hope to be useful... Greetings.
I have a program in which it insert a raw in a table after certain operations. I wan to call a web service in code behind to do some special tasks by the using of info that there is in the inserted row.
How I can do that?
Is it good idea to invoke this web service from a stored procedure or not? What are the other options?
More Details: Actually, I have an operation in my web application that take a long time to be completed and it is seriously time consuming operation. I don't want client wait until this process finish. That is why I decide write a web service to do this process in the background.
Therefore, I think it may be a good idea that when client request receive I insert his request in a table and call a web service to handle it. Moreover, I do not want to wait until web service return the result, so I will aware client from its result through the report. I do not know what is the best solution to handle it.
I usually keep myself far away from table triggers(it sounds like you're about to use an on insert trigger for a table).
I don't know your specific situation but you could either :
Call the webservice before or after you call the stored procedure, this way the data layer(stored proc) only handles data and nothing more. You're logical layer will handle the logic of calling an extra webservice.
Write a service that will periodicly read a table and notify the webservice of the latest modifications. More messy but it resembles more the effect you're trying to achieve.
There are probably more solutions but i'd need more information on what it exactly is you're doing. Right now it's kinda vague :)
It is never a good idea to call webservice from Stored procs or other DB objects. You can call it from your code, just after you execute the insert and commit it.
The problem it sounds like is that you cannot guarantee that the web service will be called unless you call it before committing the transaction. However, it sounds like the web service needs to be called after commit. In this case, it sounds like you should use a message queue. You could either build one in your database or you could use one off the shelf (http://aws.amazon.com/sqs/ or http://www.windowsazure.com/en-us/home/features/messaging/).
The steps would be:
Insert message into queue (after this is success you can return the call, depending on what your contract with the caller is)
Read message
Insert into table
Call web service
Delete message
The downside is that you will need to make the operations (inserting into the table and calling the web service) idempotent.
Could someone please be kind enough to show me the best way to determine if a webservice (ASP.NET) exists at a given URL?
I assume an approach will be something along the lines of issuing a request using System.Net.Webclient but how could I determine if it is a valid webservice and what sort of request should I issue?
EDIT: To add a bit more context I am determining if a webservice exists because I am attempting to build a generic tool that uses arbitrary webservices.
The only way IMHO to be sure the service is up is to be able to call an innocuous method on the service and verify the response. Retrieving the WSDL is not sufficient.
There is a similar SO question on this here:-
How do I test connectivity to an unknown web service in C#?
I would ask for WSDL document. If you get it back it means that the service exists and you can check to WSDL for implemented methods.
Consider reading about WS-Discovery
http://docs.oasis-open.org/ws-dd/discovery/1.1/wsdd-discovery-1.1-spec.html
I have a web service that executes a task that may take hours to finish (asynchronously)
I would like to share the status of that task by all the clients that connects to the server (I'm using a web application for this)
For example, the first client that calls the page http://localhost/process.aspx
will instantiate the web service and it will call a method to start executing the task. A percentage number will be displayed showing the status of completion. I can do this by polling the web service using AJAX.
If there is another client that tries to opens that page, it should get the same percentage information so no new instances of the web service are created.
How is the best way of doing this?
I thought about different solutions but sooner or later I find new problems.
These are some of the possible alternatives:
Create an static object of the Web service.
Create the object in the global.asax file.
Do you guys have any other ideas? I'm not too familiar designing web sites and this is driving me crazy. I would appreciate if you guys could provide some code snippets.
Thanks
The issue is ensuring that the information pertaining to the single instance of a process is stored in exactly one place.
Your initial thinking can be applied, for instance, by using the Application object, but that will break down in a clustered IIS scenario.
I am not posative that a database is the absolute best solution, but I believe it would give you what you want.
If 100 clients try to start the process at the same time, only one can succeed, right? The databases locking facility will help you make that happen.
There's a method (I'm assuming WCF for the web service) that allows you to have exactly one instance of the service run... link
I think this is what you are trying to accomplish.
Assuming I have understood your requirements correctly. Your webservice should not be creating the instance of the “worker” object.
Your webservice request should log to either a database (as the other poster noted) or a messagequeue of somesort. At this point your “worker” processer (probably some type of service) should take over the job as it requires.
Basically you want to break up your application into something like this
| Webservice | ---------- | Datastore |-----------| Worker |
Any further requests regarding the batch should be managed by the webservice querying the datastore.
Remember webservices are NOT DESIGNED TO DO WORK.
I'm currently working with web services that return objects such as a list of files e.g. File array.
I wanted to know whether its best practice to bind this type of object directly to my front end code for example a repeater/listview or whether to first parse it into my own list of "file class" e.g. customFiles[]
If the web service changes then it will break my front end code, however if I create my own CustomFile class, then i would only need to change my code in one place to fix the issue, but it just seems like a lot of extra work to create the same classes from a web service, i wanted to know what is the best practice for this type of work.
There is a delicate balancing act in properly encapsulating implementation details. Too little encapsulation is a maintenance nightmare as small changes in any area break the application. Too many layers is a different kind of maintenance headache altogether.
In this particular case I would create a small layer in your application to encapsulate the web service calls. This will ease your maintenance in both the application and the service as they will be loosely coupled.
It sounds like you have already answered your own problem. Best practice is to create your own custom class for the reasons you point out, but it is significant extra work.
If the webservice isn't likely to change then just use the existing classes, but if you need to cater for change then create your own.
Returning a class is fine as long as your client knows how to deserialize it. If it's truly a web service, where you don't have control over both ends of the conversation, it's more common to start with schemas for XML request and response streams. That decouples the client from the web service a bit more and allows any client that can send XML via HTTP and consume an XML response fair game.