Out Of Browser Silverlight app with local offline database and WCF-RIA - silverlight-4.0

I have the following scenario:
We develop a silverlight 4 app for our customers, that will be used as an out-of-browser app. The app is working offline, i.e. app and database are on the users local machine. The app is using WCF-RIA-services to connect to the local database. The database will be an SQL Server Express, SQL Server CE or MySQL. We are using MVVMLight and MEF.
An external webserver is only used for updating the app from time to time or adding new modules to the app. To achieve this we do something similar as shown in Jeremy Likness blog (http://www.wintellect.com/CS/blogs/jlikness/archive/2010/05/25/silverlight-out-of-browser-dynamic-modules-in-offline-mode.aspx )
The reasons why we are doing such a scenario are complex. But to keep a long story short it is mainly for compatibility reasons for a later online version and we don't want to use WPF. So we need to get this working with Silverlight and WCF-RIA services.
Ok, that's the scenario and here's the question:
Do we need a local webserver in this scenario? The app is programmatically installed as out-of-browser, the database is local and connected via WCF-RIA.
If yes, which webserver would be sufficient? It should be installed and configured via an initial setup that is executed by the customer. The customer should not have to do anything with configuring the webserver.
Any other ideas or comments on this scenario? Any other possible solutions for this?
Thanks for your help
Dirk

silverlight wasn't meant to be used this way I think. So it would be like when you are developing app in visual studio and use Cassini to see result - everything runs locally - but you still need a web server. Maybe more info here - http://www.infoq.com/news/2010/06/WPF-vs-Silverlight

I´m not able to provide with a full answer to your problem, as we are currently facing the same problem. (WPF not being cross-platform, Very specific hardware on some clients)
But I may share some of our thoughts on our type of Thick-Silverlight-Client:
To keep deployment etc. simple we use a self-hosting process (installed as background process)
We may not use RIA as the background process has to run using Mono VM (but for MS-only solution see Can WCF RIA Services be self hosted? )
Architectural thoughts on standalone "Clients":
Depending on your requirements implementing a server for each client communicating with the "main"-server by messages (NServiceBus) may be overkill. But if you want to use a client database if offline and silverlight for ui you should consider using an event-driven-architecture.
There is a slideshow on combining "Event-Driven-Architecture" & "CQRS" with Silverlight. But i would not use it as a blueprint more like an inspiration.
http://www.slideshare.net/dennisdoomen/cqrs-and-event-sourcing-an-alternative-architecture-for-ddd

Related

Bundle WCF service along with Universal Windows App

I realize that we cannot directly access SQL Server database from a UWP app, and have to use a WCF service as a mediator for this. (Which is totally stupid, since even competitors like MySQL provides API for Microsoft's runtime, while Microsoft's own RDBMS does not!)
I don't have any experience with WCF, but after going through some tutorials, I believe I can make a WCF service to communicate with my SQL Server (although I do not like making my simple application use a 3-tier architecture, which shouldn't be imposed on me). Anyways, I do not want to host this WCF service on my website, since I'm making this only for this UWP app. Is there a way I can bundle/pack this WCF service along with UWP app itself, such that service runs on client machine only when thhe start my app, and stops later when app is closed/suspended/minized.
The UWP app I'm developing, also have a WPF version and a web version (in ASP.NET), all of which were connected to MySQL database till now, and it worked flawless. Recently I decided to shift to SQL Server since I'm using Microsoft technologies for all my softwares and thought SQL Server will have better integration and support. But now I find it rather opposite, and thinking to switch back to MySQL database.
You can not bundle a WCF service (or REST api) with your Universal Windows app. UWP apps run in a sandbox environment on a different .NET runtime than your WCF service. You could run the WCF service in IIS, or even better create a self-hosted ASP.NET WebAPI project (so no need for IIS) to access your database. But this service will have to be installed separately from the app.
Note that because UWP apps run in a sandbox, some in-app databases like SQLite are inside this sandbox and can not be accessed by your other apps (WPF, website) by default (there are some hacks to bypass this).
So I think your best bet is to stick with MySQL and use the MySQL connector.

Want to Run VB.Net Desktop Application in web Browser as Web Application

I have a Small ERP Financial Software developed in VB.Net and SQL Server consisting on modules
HRM, Accounts, General Ledger etc.
Now i want to run some module on web but Creating all application in asp.net or other web tools is too much time taking.
Is There any way to run this Desktop application on web espacially in Web Browsers. ?
Any Help.
If you don't want to re-write your application you could have a look at Go Global.
I can't vouch for it as I have personally never used it, but I know of people who have.
I have tested that for a proof of concept on the past and it runs great. Called .net zero deployment, you can look it up. The only concern is off you need database access, remember that you are paying through the port 80, so a need for a web service to access database call may be needed. Not sure of I have still the code trial, but I can look.

How to separate development of client-side web UI and the server side

I'm in the process of providing a Web UI as an alternative to our current desktop UI for our C/S enterprise application.
When developing the client-side in our desktop version, UI developers could connect to any server so they only needed the client-side environment.
When developing a Web UI (Client-side JavaScript in the browser), we are bound by the browser's "Same origin policy" so the UI must talk to the same server from which the UI code is downloaded.
As far as I see it till now, the development scenario for the UI guys is:
Developer installs server on local
machine and runs it.
Developer edits the HTML+JS+CSS files on local installation.
Developer has to reinstall/update server on local machine each time there's a need to test UI code against new server behaviour.
This does not seem too comfortable, at least compared to our previous C/S style development.
Are there any other ways you can suggest to that will not require UI developers from installing and updating server side components on their development machine ?
Or anything else related that can simplify the development process ?
Thanks :-)
Editing in some clarifications:
I'm mostly interested in the aspects of UI coding, not UI design.
I need a lot of server interaction - getting data from RESTful web services, which are developed in parrallel - hence the need to have an up-to-date server
You haven't specified the development platform.
As far as pure HTML/JS/CSS is concerned, you don't need a server. The UI developer can fine tune UI components locally.
The moment you want to talk/integrate to Server (via AJAX, JSP, ASP...) then you need to connect a development server as now your changes have to be served by Server.
Most of UI fine tuning can also be done from Firebug
In our office when changes to styling are required we save the page as a local copy and send it to the UI designer, he makes his changes and we integrate them. So the UI designer don't have to maintain a development environment.
JSONP lets you work around the same-origin problem (with server support) -- check it out! If the front-end-in-the-browser developers are using a good framework suc as jQuery or (my favorite) Dojo, JSONP should be no harder for them than plain JSON.
Develop on a shared server, but depending on the size of the team.. that's challeging with respect to version control.
Or deploy automatically generated virtual machines with nightly builds, so the devs don't have to install, but always use a recent version.
In the case of UI developers depending on a common REST server, the UI development can be done on the local machine and the REST service should be on a central server. When changes are made to the REST service these should be deployed to the central server (when stable), so all developers can use the newest version (this also helps with testdata).
You could try using a proxy on the developer's machine where some paths redirect to the server and some paths redirect to local folders.
Hmm, I actually didn't really get any information on what kind of technology you're using. If - with UI Developers - you mean designers, which have to take care about the CSS, layout etc, then we do it the same as lud0h said. We (developers) send the UI designers a copy of the server-side produced HTML pages. They then edit the HTML pages according to accessibility guidelines, CSS and layout and send us back the outcome of their work. We use their HTML pages then for integrating them in our web applications.
If you don't just mean tuning CSS, but also to write JavaScript / Ajax functionality you HAVE to use a server with which you're communicating. As you said, normally this is done by having a local environment which is similar to the server-one. In .Net Visual Studio '08 provides an internal webserver, alternatively you have to install IIS locally. In Java environments you have to install Tomcat and related technologies. In my eyes this is a must. What you have to have is
Versioning system (CVS, SVN,...) where developers commit regularly (minutes/hours)
local environments where developers checkout the source from the repository and develop
Test server where you deploy on a daily basis (could be like daily builds) in order to test your running product
I guess this should be what a professional development environment should consist of. The difference to C/S application development is that web UI and web-client code are not that separable as a Client UI in C/S environment from the server-side. Unless you develop with technologies like GWT or Silverlight which are quite similar to C/S, just running inside the browser, but communicating over RPC calls or web services.
//Edit:
What I nearly forgot. Don't do something like developing on the server directly, meaning that all of the developers access the server's filesystem where the code, UI etc. lies!!
You can use CORS. a new technique just like Ajax, but with ability to make calls on other domains. so you will need only one UI on one server. think this can help you.

Desktop Based Application

What is a better platform/language for developing Windows/desktop based application that can run offline (sometimes)? .NET (C#, ASP) or Java or any other development tool? This application requires to store data into a database(involves some GIS) and later Synch both ways with the main server (SQL/Oracle) during off hours or when initiated by a user or event or when online? ALso the tool/IDE recommended should allow us in the future to migrate this desktop application as a Web based application to the corporate server with less pain or re-work when internet/nw access is available to all of our remote sites/users. Any input/advice is appreciated.
If you are strictly doing Windows desktop application development, C# or VB.NET would be an excellent choice. There is a ton of documentation out there for .NET developers. Although the framework is a free download from Microsoft, any serious work is cumbersome and tedious without the IDE.
If you needed the potential to support your application on multiple operating systems besides Microsoft Windows, then I think it might be worth looking into Java.
For web solutions, in .NET you have ASP.NET, Java you have JSP and Tomcat.
You could try Adobe AIR. It seems like it would serve most of your desktop needs and it should be the easiest to migrate into a web app (Flex).
C#/WPF for desktop with Silverlight, XBAP or even ASP as the online options.
Since you mentioned the desire to web-enable this application at some point I'd look into Silverlight. Out-of-browser capabilities were introduced in Silverlight 3. That means that the app can run directly on the desktop, and the internet connection is optional. However, when the internet connection is available it has built-in support for auto-updating itself.
And now in Silverlight 4 it's possible to run an out-of-browser Silverlight app with elevated trust. Silverlight 4 also finally introduced things like right-click support, clipboard access, full keyboard support in fullscreen mode, etc. So if you're just now starting development, I'd most definitely use version 4.
You'll have to communicate with something like a WCF service for a lot of the database operations. But going with Silverlight should allow you to build something that'll work on the desktop and the web alike without having to manage two systems.
Going web-based after you already developed a desktop application is a really bad idea. There is no reason the desktop application cannot use a internet connection, and be updated from a server.
You could try Delphi. It's a rapid application development tool. Very different, but very quick to use. Well suited to Oracle integration. Data sync is probably going to need to be custom, unless you're using something like Sybase SQL Anywhere.

Monitoring a Custom Service

I've created a service for one of my apps. How do i create a system tray component in VB.net that can be used to monitor the progress of the service? Is there a way to have this installed via tcpip on multiple client machines such as those that are for our employees?
We do exactly that here, with the server running a really basic HTTP server on a configurable port on a separate thread that returns status in an XML format (nothing else, just that) -- the client just uses a web request to get the XML, before parsing it and displaying it appropriately.
This approach also allows for future extensibility (detailed status, sending service control commands, adding an association to an XSLT file elsewhere for use with a normal web browser, etc.)
You could use WCF for this. Using WCF your service would open up an EndPoint which would expose status information to callers. You could then build a tray icon application that can be deployed to the employees workstations. The tray icon application could periodically poll the WCF service the your Windows Service is hosting and get status information. I know #Johan mentioned Remoting already and this is a similar approach. I'd recommend WCF though as the programming API is more simple, IMHO, and WCF will give you more flexibility with regards to network transports, etc.
I guess your question is not about how to actually do the "traybar"-thing, but how to communicate with the service to get the information you want to show in the monitor/traybar-program?
It can be done in many ways, API is one way, use sendmessage/postmessage/getmessage is one way to make 2 running programs communicate with each other without having to store anything in files or databases first.
DDE is another way. If it needs to do the stuff via net then there is something called NetDDE, but I havent done anything with NetDDE I cant help anything there.
But about the API and DDE, feel free to ask more questions if you want some clarification.
I'll take the second question: Is there a way to remotely install software on client machines?
Yes. However it is very dependent on your environment. For example, if you have an Active Directory domain, you can use group policy to force installation of software on the client boxes.
If you don't like that or if you aren't on active directory, you can buy something like Altiris to push installs down.
Another option would be to use login scripts which would run a custom program to detect if your program is installed and take appropriate action. But then you are probably better off buying Altiris.
For the comunication part, i have used remoting before, and this works very well. With a little bit of configuration, you can even get it working to another machine.