So, i'm building my first SL application.
I tried to use the MVVM approach, and I think that's the way for me.
Basically, it's a simple application which shows data to the user, the data source is local (maybe in the future will be centric, but right now this is not the case), and the data should be retrieved by:
A. Calling file system's reading
and
B. Method calls from External DLLs
So, as I said, I started to work with MVVM (used this tutorial). I have 3 components: the service, the SL application and the project that host the SL app (excuse me if i'm not using the exact proffecional terms...).
My question is: Do you think that I've chose the right design? if so, is there any way not using IIS to host the service or is it a must? (I don't want to spend time on adminastrative tasks on clients' computers), because as I said, the data is local at the moment and IIS feels unnecessary.
I'll appriciate every comment on this. Thanks!
EDIT:
I'll try to simplify my question: I need my SL app to communicate with some kind of service - that will be able to take requests and reply back to the app.
This service suppose to be able to use .net dlls, and this service should be locally on each client run the app.
EDIT:
I noticed the Self host option.
Does anyone has any experience with it?
If your question is about: You having access to a database server somewhere, you should try WCF RIA Services. This will allow you to create service for each entity and the service will get included into your host project or you can even create a WCF RIA library.
As suppose to your MVVM pattern. I prefer splitting my Views from my ViewModels In different projects. I like to see them as a seperate layer.
Actually using ria services may mean that you have a number of services which apply to one user, but yes they are specific to the user. Which file system would you be attempting to access? The client or the server?
I finally decided to go with XBAP(WPF XAML Browser Application).
It suited perfectly to my requirements:
1. no deployment issues - just press a link, and .net enviroment will do the rest (downloading the needed assemblies, install them and finally run the app)
2. it's hosted on a browser
3. no IIS is needed!! it's a client-only application
Related
I am working on a project requiring communication between the Presentation layer (MVVM based client) and the Business layer. The application is to be installed on a single machine, and as such could have been executed using a .net remoting based approach. However, I have been suggested to use WCF since .net remoting is deprecated and WCF is the way to go.
So I implemented WCF Service as a WCF library project. I added a service reference (using visual studio tool by discovering services in the solution), which was successfully added on the client side. All works well, since during debug session visual studio launches the service library and the client can connect to it successfully.
Now Since the client and service host will be installed on same machine, I was thinking of using named pipes transport and self hosting for the WCF service. Here is where this gets very confusing to me:-
Since the MVVM client is the "main" app (since it is the application frontend), the client will be launched first. I am unable to come up with a solution to launch the service host "on-demand" when the client needs the same.
What are the solution I can use to do what I require for 1? I am not sure of using a continuous service through windows service for something that will be required "on-demand".
Please suggest clean approach to implement a way to launch "on-demand" service.
Thanks in advance.
I'm not quite following you here. MVVM is cake and really doesn't have anything to do with your problem. Using a servicebased architecture is a must today, I just want to smack every old guy/gal sticking to direct SQL on the client side, and don't see the dangers with that.
Well anyhow, you may solve this different ways. WCF is BIG, to big in my opinion. One way to use it, common on small applications like apps(WP8.1, 8.1 apps++), is just to connect, call the method you need and the close the connection. Case solved, given that I understand your needs. The otherway is to keep the session alive for each service... (ugh, loadbalancing etc).
I've been working on large LOB applications the last 4 years my self, what I can tell, is that if I were in charge, I would have done it very differently. For once I would used JSON endpoints with SSL over HTTP, and the json.net serializer. The datacontract serializer which is the default in WCF, is not good news at all. JSON allows easy communication with JavaScript based applications, and the serializer doesn't break like porcelain as the datacontract serializer does. Address/baseaddress may be stored in your config file, so it may be changed upon deployment(you probably have many servers, for different environments).
This is a really old post covering the subject(supporting SOAP aside JSON); REST / SOAP endpoints for a WCF service
Don't be stupid and just call your services directly now! Use the interface(Wrap if necessary) and feed it to your viewmodels for proper TDD! It will also allow you to completely replace WCF with another form of communication.
There also are alternatives to WCF.
IIS? Hosting WCF in IIS rather than a proper service? No way, flush that idea down the waterloo ;) (internal joke)
EDIT:
BTW: Your service must ofc already be running for your client to connect to it! Or nothing will be listening to your configured port. If you are selfhosting, you can use parameters to start in debug mode, that is start your service like a regular application you may debug. In Program.cs;
if (args.Length > 0 && String.Equals(args[0],"debugmode", StringComparison.OrdinalIgnoreCase)
{
Service1.Create(); // Debugging!
}
else
{
// Hosting
service = new Service1{ServiceName="YourService"};
ServiceBase.Run(new ServiceBase[] {service};);
}
Hope it helps,
Cheers,
Stian
I am working on an in-house, iOS app that will need read-only access to a SQL Server with multiple databases. I know the stock answer here is "write some web services", but I'd like a solution that is self-contained. Is there any way to directly connect to a SQL Server database from an iOS application? I'm thinking something like a basic ODBC connection.
I've seen a lot of users asking this question, but very few answers other than "write a web service." Is that really the only way?
A web service is indeed the only way, but Red Gate's written one you can reuse:
http://www.mobilefoo.com/iSqlServerSDK.html
http://labs.red-gate.com/Tools/Details/iSqlSDK
It's not officially released yet, just in beta, so keep in mind that features & prices may change.
Actually the easiest way is to create a MVC 3 or 4 asp.net web application. call the web methods. You don't need any API to pay for.
I use SBJson to serialize domain object and then send the objects as serialized jSOn to MVC 3. It's super easy to do. I even send images with base64, so it's .net compatible.
See my blog post with sample code:
http://nickturner.wordpress.com/2012/10/09/107/
So, after much searching and trial and error, unfortunately the best (only?) way I've found is indeed using Web Services.
Fortunately, Linq to SQL makes the WCF-creation-side incredibly easy. Once I got someone at work to walk me through setting up a Windows web server and adding the web service (and buying access to an online web server), the Windows side was up and ready to go.
I'm still working through all of the syntax stuff on the SOAP interaction side, but keeping my different methods somewhat similar in structure allows me to tinker a little until it works. By this time, I think I've gotten it to work pretty well.
So, both answers I got back were (disappointingly) correct. The only way to interact is through a Web Service. Even the 3rd party solutions they mentioned were really just convenient wrappers around the same type of technology. As it turns out, I'd rather have finer control over the process.
One word of advice: Get a real, external web server. I tried doing this on a non-Server Windows VM on my iMac/MacBook Pro, and it was like pulling teeth! Once I actually got access to an external, full, stand-alone web server, the process was much more streamlined and easy. Do yourself a favor and take that headache out of the equation!
There was a SQL ISAPI extension as part of SQLXML, but I think it has been deprecated: http://msdn.microsoft.com/en-us/library/aa226559%28v=SQL.80%29.aspx
This was effectively a pre-built, and relatively open, web service - so I'm not sure this counts as a direct connection.
You could also check out http://odbcrouter.com/Main
I have tried what seems like about a dozen different methods of uploading files to sharepoint from a silverlight application. They either have severe limitations (file size limits of less than a meg or so) or lots of security issues that I have not been able to over come. I have tried:
WCF (We are trying not to use any custom WCF services at all FYI though this is the method that I have gotten to semi work)
Sharepoint Web services
Client object model
HTTP put
Webclient write stream
I have seen lots of different examples out there of people doing completely different things but none seem to work and all seem like they are the "old" way of doing things. I am using silverlight 4, sharepoint 2010 on IIS 7. Is there a best practice for uploading large (say 20-30 meg) files? I just want to dump a file into a document library.
I had similar issue. Tweaking web application level setting from central admin, changing asp.net limit in web.confit and following article helped me.
http://blogs.msdn.com/b/sridhara/archive/2010/03/12/uploading-files-using-client-object-model-in-sharepoint-2010.aspx
Just had a thought silverlight has a thing called an HTML Bridge which allows it to interact with the rest of the page. Consider calling a javascript function from Silverlight, and let the javascript function do the actual upload
UPDATE - the Javascript ClientOM doesn't seem to have the SaveBinaryDirect method :-(
How about doing some ExecuteQueryAsync and then in the success call back function (no longer on the UI thread), using the Microsoft.SharePoint.Client version of File? I know this would require downloading the larger assembly, so perhaps that's not so good.
I wonder if there is a way to get the clientOM use a more efficient binding when calling the web services...
Martin
The default upload size limit for the SharePoint client object model is 2 MB. You can change that limit by modifying the MaxReceivedMessageSize property of the service.
This can be done in two ways:
programatically - as described in this link - tho this won't work in Silverlight for example
trough the powershell. On the server where you have SharePoint installed, fire up the SharePoint Management Shell (make sure you run it under the farm administrator account) and run the following commands.
$ws = [Microsoft.SharePoint.Administration.SPWebService]::ContentService
$ws.ClientRequestServiceSettings.MaxReceivedMessageSize = 52428800
$ws.Update()
This will change the upload limit to 52428800 bytes - or 50 MB. Now, restart the website hosting your SharePoint site (or the entire IIS) for the changes to take effect.
Currently I have a working Silverlight application that uses .Net RIA Services.
It's structure:
Client-side
Application.Client.UI.dll (Xamls and
basic UI stuff)
Application.Client.BL.dll (Contains the Link to RIA and most of the business logic)
Server-side
Application.Server.Data.dll (Server-side dll that holds the Entity-model and it's generated domain service)
Application.Server.Web.dll (Only the ASP.net hosting container, which references the
Application.Server.Data.dll)
I placed most of the business logic on the client side (Application.Client.BL.dll) for better user-experience (fast reactions) and to free up server resources. My challenge is now to re-use this client-side dll including it's RIA data access capabilities, in a server-side windows service. I'm wondering, is that possible at all? Is the Application.Client.BL.dll still able to consume the existing RIA service, or does that dll require the Silverlight runtime to identify/locate it's service target, and therefore will not work anywhere else.
Curious for your answers
You really shouldn't put any business logic on the client, the guys in security and / or architecture will hate you for it ;-). Furthermore you can't use Silverlight assemblies in ASP.Net or Desktop projects and vice versa. If memory serves correctly, Silverlight uses an entirely different CLR altogether.
I encountered similar needs when working with compact framework assemblies I also wanted to compile for the full framework. I'll describe how I would work around this scenario.
If there exist any issues referencing the Silverlight assembly, consider building two projects as follows:
Project #1 would be your Silverlight library, and should contain all the source files you want to use on the client.
Project #2 would be your Windows Service. Instead of including source files directly, use the "Add Existing Item", find the original source file in project #1, then (and this is the magic), drop down the Add button to choose, instead, choose "Add as Link".
By including the source file as a link, you retain the ability to maintain your source code in one location, but add the ability to compile your code for multiple frameworks. As long as the code relies on assemblies available in both the Silverlight framework and the full .NET framework, then you're money.
Now, regardless of whether you choose a multi-project approach, know that domain context classes have additional constructors that allow you to specify contextual information, such as the URL, for the corresponding domain service. I use the following code in one application to construct a domain context for a domain service that provides personnel data:
var context = new PersonnelDomainContext(
new Uri(ConfigurationManager.AppSettings["PersonnelServiceUrl"]))
In this case, the URL looks something like:
http://website-url/Services/Hyphenated-Namespace-PersonnelDomainService.svc
Of course, when writing a Windows Service, nothing is stopping you from referencing the server-side domain service (not context) assembly directly. With the domain service in hand, you can instantiate a service instance without all the additional configuration and without the additional network XML payload. There are trade-offs to this approach, such as forfeiting centralized configuration management (such as connection strings), but depending on your circumstances, you may find the trade-offs to be worth it.
Happy coding!
Have you considered using fork-reuse? Take a look at:
http://sharednow.blogspot.com/2011/05/its-not-just-reuse.html
I've done some cursory reading on Silverlight and data access. From what I can tell, I'll need a web service to hook up a Silverlight application to a database while it's running in browser. Is this true when it goes OOB? Or is there another method that should be used then?
Some background:
We have a .Net 2.0 Winforms application. We're trying to convert the functionality to a web app of some sort without rewriting the business logic. Our internal web developers all write in ColdFusion, so Adobe Air seemed to be a natural fit. However, we've found out that the only way to consume a .Net dll in Air is to write an EXE that makes function calls. (Perhaps something like a WCF service on the local machine.) Since that's the case, I thought I'd see how the data access was in Silverlight OOB, because we will have customers with limited-to-no internet connectivity and will need to be able to access an offline DB.
As far as I know, whether it runs in or out of browser it will need a web service or other means to hit a database. You cannot do it through the Silverlight application because of the sandbox security model used.
In 4.0 there is the added use of COM so you may be able to use that to your advantage.
Otherwise you would just be using a file stored in IsolatedStorage to persist data to, like an XML file for example. Maybe this is what you are looking for though?