I need to deploy an application onto some Windows machines for purposes of data collection from a group of people (i.e. the application will be used to gather responses to a series of survey questions). The process is interactive, alternating between displays of text and images with specific timing requirements. I have put together a prototype application using HTML and JavaScript that implements the survey. However, there are some unique constraints on the deployment environment that have me stuck:
While the machine is Internet-connected, the client requires that the survey application must run fully local to the PC that it runs on. Therefore, sending the survey results to a remote server is not permissible. Obviously, saving to a local file from a Web browser is typically not permitted for security reasons.
Installation of applications onto the machines that will run the survey is not permitted.
The configuration of the machines is not known specifically a priori, but I can assume some recent version of Windows with IE8+.
The "no remote access" requirement was a late comer, and has thrown a wrench into the plan of just writing a simple Web application that could post results to an HTTP server. I'm now looking for the easiest way forward. Two main approaches come to mind:
Use a GUI framework that provides a control that can display HTML/JavaScript; running a full-blown application on the PC would allow me to save the results to the filesystem. I've never done this, but it seems like in this day and age it shouldn't be too difficult. This would allow me to reuse much of my existing prototype implementation, but I would need some way of transferring the results (which would be stored in a JavaScript data structure) outside of the Web control to where the rest of the application could access it.
Reimplement the entire application using some GUI framework (I've used PyQt successfully before, although not on Windows). This approach is obviously less desirable than #1 due to the lack of reuse. However, it may be necessary if #1 isn't feasible.
Any recommendations for the best way to go? Ideally, I'm looking for a solution that can be run in a "portable" manner from a USB thumbdrive or similar.
Have you looked at HTML Applications (HTA)? They work in IE5+ and can use Windows Scripting Host to write to local drives and UNC shares...
Maybe you can use a portable web server with a scripting language on the server side. http://code.google.com/p/mongoose/ Mongoose, for example, you can run PHP, CGI, etc. .. scripts. Then, simply create a script to save a file to your hard drive. And let the rest of the application in the same manner.
Use a script to start the web server, and perhaps a portable web browser like K-Meleon to start the application http://kmeleon.sourceforge.net/ This is highly configurable. Or start the system explorer to your localhost URL.
The only problem may be that the user has to modify the firewall for the first time you run the server?
Related
I am looking for a simple way to send messages between a Winforms Application and a Windows Service. The service will be run under LocalSystem so will be able to install updates to my Winforms App. The app is run in very locked down environments where port will be blocked and the file system is not reliable enough to use it for logging. I have tried using Named Pipes but i could not get this to work. I want to keep it simple so was thinking of trying Memory Mapped Files?
I only want to pass simple strings back and forth between the app and service, e.g.
APP-> Service [Please download this file http... and place it here C:\Program Files...]
Service->APP [0% downloaded]
Service->APP [1% downloaded]
etc..
Service->APP [Update Complete/Failed]
I cant seem to find a good example of how this can be achieved? Is memory mapped files the best way to go? If so, where do i start?! I have been reading through this Post but i cannot seem to make sense of it, its been a long day! I want everything to be in memory, unlike in this example. Can anyone help?
! For the sake of simplifying things I will refer to Windows Store applications (also known as Metro or Modern UI) as "app" and to common desktop applications as "application" !
I believe this is still one of the most unclear yet important questions concerning app-development for developers who already have established applications on the market:
How to manage communication between apps and applications on a Windows 8 system? (please let's not start a debate on principles - there're so many use cases where this is really required!)
I basically read hundrets of articles in the last few days but still it remains unclear how to proceed doing it right from the first time. Mainly because I found several conflicting information.
With my question here I'd like to re-approach this problem from the viewpoint of the final Windows 8 possibilities.
Given situation:
App and application run on same system
1:1 communication
Application is native (written in Delphi)
Administrator or if required even system privileges are available for the application
In 90% of the use cases the app requests an action to be performed by the application and receives some textual result. The app shouldn't be left nor frozen for this!
In 10% the application performs an action (triggered by some event) and informs the app - the result might be: showing certain info on the tile or in the already running and active app or if possible running the app / bringing it to the foreground.
Now the "simple" question is, how to achieve this?
Is local webserver access actually allowed now? (I believe it wasn't for a long time but now is since the final release)
WCF? (-> apparently MS doesn't recommend that anymore)
HTTP requests on a local REST/SOAP server?
WinRT syndication API? (another form of webservice access with RSS/atom responses)
WebSockets (like MessageWebSocket)?
Some other form of TCP/IP communication?
Sharing a text file for in- and output (actually simply thinking of this hurts, but at least that's a possibility MS can't block...)
Named Pipes are not allowed, right?
There are some discussions on this topic here on SO, however most of them are not up-to-date anymore as MS changed a lot before releasing the final version of Windows 8. Instead of mixing up old and new information I'd like to find a definite and current answer to this problem for me and for all the other Windows application and app developers. Thank you!
If you are talking about an application going into the Store, communication with the local system via any mechanism is not allowed. Communication with the local system is supported in some debug scenarios to make app development easier.
You can launch desktop applications from Windows Store applications with file or protocol handlers, but there is no direct communication.
So, to reiterate the point... communication between WinRT and the desktop is not allowed for released Windows Store applications. Communication between the two environments is allowed in debug only.
The PG has posted in different places reasons for why communication is not allowed, ranging from security, to the WinRT lifecycle (i.e., you app gets suspended - how does that get handled re: resources, sockets, remote app, etc. -- lots of failure points) and the fact that Store apps cannot have a dependency on external programs (i.e., I need your local desktop app/service for the app to run, but how do I get your app/service installed? You cannot integrate into the Store app. You can provide another Store desktop app entry, but that is a bad user experience.) Those are high level summaries, of course.
How does one go about testing the server-side performance of a web application?
I'm working on a small web application (specifically, it will solely be responding to AJAX requests with database rows). I want to see how it performs under load. However, I cannot upload it to an internet host right away. The development environment is, however, part of the local intranet, so I can use as many machines as I want to hammer the development server, presumably using Python in conjunction with urllib2.
My question is, is such an approach really accurate for determining the high-load performance of a server-side script? Is there a better way to do this? Am I missing something here?
Have you tried a tool like Apache JMeter? http://jmeter.apache.org/
Why bother with multi-layer RIA if Internet now is fast enougth to do "traditional" fat client C/S?
What just use a plain C++ / Delphi / Oracle Forms / JAVA-Swing application talking directly to RDBMS thru Internet?
A very complex compiled exe program in Delphi is about 10MB, that amount of code downloads in a couple of minutes in a decent 1MB ADSL connection.
After all what is what we are doing with AJAX / BlazeDS / JSON / etc pushing thru http/https protocol but with a lot of layers and a lot of points of failure...
Comments please...
First a bit about terminology, what you refer as "traditional fat clients" are probably desktop software. Web applications are often written as thin clients, but they can also be written as fat clients. A fat client rich internet application are client centric, which means that a lot of the work is done in the client (browser). Fat client RIAs can be written with the help of technologies such as AJAX or Adobe Flash.
To compare the advantages of web based applications over desktop software:
Maintainability: One of the advantages of web based applications is the maintainability of them. You only have to make one installation of the application and then it is directly available for all users. Same goes for updating of the software, you only need to update the software on the server and then you can be sure that every single user is using the latest version of the software. This eliminates the need to update individual installments of the application on the users' computers.
Security: There are two positive security implication in using web based application. As said previously, you only need to update the software in one place. This means that the users always have the most up-to-date version of the software in use, thus eliminating the problem of people using outdated, vulnerable version of the application.
What is more important, is that fat client applications are insecure. They expose application logic and possibly sensitive data such as database credentials. Fat clients can be reverse engineered and attacks can be crafted based on the gained information. For an application to be truly secure, the application logic should stay on the server and the client should be thin and only server as a presentation layer for the information handled in the application. Do remember the exposure of application logic can also affect rich internet applications. It is easy to write RIA in a way that it exposes application logic. Hence it is important to remember that the application's state should always stay on the server, the browser is, as said, only means for presenting the data. In other words, both web based applications and desktop applications can be (in)secure, I'd just say that there is a greater risk of pushing application logic to the client when writing desktop software.
Platform independent: Web based applications are platform independent (with the exception in application that use platform specific functionality, such as activex). This means that your users can be using the application from a mac, a windows or a linux computer, it doesn't matter. Of course, it is unfortunately easy to create web applications that do not work/only works on specific browsers, such as Internet Explorer. Although, it is much easier to make a web application cross-browser compatible than to write a desktop software to be truly cross-platform compatible.
Accessability: If you are connected to the Internet/Intranet, you have access to the application. It doesn't matter if you have borrowed your friend's laptop or if you are sitting by your desktop computer, you still have access to the application since it doesn't require you to install anything on the computer. Just browse to the application URL.
I have an existing GUI application that should have been implemented as a service. Basically, I need to be able to remotely log onto and off of the Windows 2003 server and still keep this program running.
Is this even possible?
EDIT: Further refinement here... I do not have the source, it's not my application.
Windows services cannot have GUIs, so you will need to either get rid of the GUI or separate your application into two pieces - a service with no UI, and a "controller" application. If you have the source code, converting the non-GUI code into a service is easy - Visual Studio has a 'Windows Service' project type that takes care of the wrapping for you, and there is a simple walkthrough that shows you how to create a deployment project that will take care of installation.
If you opt for the second route and need to put some of the original GUI code into a controller, the controller and service can communicate via WCF, .NET Remoting or plain socket connections with a protocol you define yourself. If you use Remoting, be sure to use a "chunky" interface that transfers data with as few method invocations as possible - each call has a fair amount of overhead.
If the UI is fairly simple, you may be able to get away with using configuration files for input and log files or the Windows Event Log for output.
Has anyone used a third party product like: Always Up?
Seems to do what I need. It's the capability to keep running through login / logout cycles I need. And the capability to ignore that it's a GUI app and run it anyway.
They must be linking into the exe manually and calling WinMain or something.
You can wrap it up into srvany, though you may need to assign it an actual user account (as opposed to LocalService or some such)
I've had good experience with winsw. I was able to convert quite easily my batch files to services using it.
I've used it for nginx as well, per this answer.
Do you actually need it to run as a service or do you just need it to stay running when you aren't connected? If the latter, you can disconnect instead of logging off and the application will continue running. The option should be in the drop down list after choosing Shut Down or you can call tsdiscon.exe.
Do you have the source? In many cases the difference between a stand alone application and a service are minimal.
Most of the changes are related to hooking the code into the service manager properly. Once done, you'll know that any problems that occur are a result of your programming and not any other program.
What happens if you create a service. That service is configure to interact with the desktop. Configure it to run a some user and to start automatic. From the service CreateProcess on this other application. I'd guess this is quick to try using C# (C/C++ was alot of code to even be a service if I recall). Would that work??
BUT!
My first thought would be to create a virtual computer in a server-class virtual host (like Virtual Server, HyperV, VMWare). Those virtual machines will run as service (or whatever Hyper V does). The virtual machine would always be running - regardless of logging in and out.
Make this virtual computer auto login to windows (TweakUI can set this up) and then just launch the GUI app using a shortcut to the Startup folder. You can even remote desktop into it use the program's GUI (I bet Always Up can't do that).
You can use ServiceMill to achieve this operation.
Basically you install ServiceMill Server on your server.
Then click on right button over your executable file and "Install as a ServiceMill Service".
Next you configure some things (user/password, if you want to interact with desktop or if you prefer to hide the ui... and set the start mode to automatic).
Another tool from Active+ Software can be a solution, ServiceMill Exe Builder which allows you to create services from Command Line and this is great if you are using a Continuous Integration Server or if you plan to distribute your component as a service without having to think about service integration (plus it is royalty free).
FireDaemonPro turns most GUI apps into services; it's not free, but it might be worth getting it.
First I would have to ask why your service needs a user interface. Most likely it does not but you probably need a client that gets data from this service. The reason services don't usually have GUI's is they may not have a window environment to run in. Services can start and run without a user logged in to the machine. In this case there would be no desktop for the service GUI to run in.
Having said that you can set properties on the service to run as a user as suggested by Mark. You can also specify in the properties of the service to "Allow service to interact with desktop". Only do this if you know a user will be logged in.
A service shouldn't have a GUI, since it should run without any needing any intervention from a user, and there are all sorts of problems associated with finding and communicating with the correct users desktop.
Since, presumably the reason for asking this is to be able to remotely monitor the application, the way to do it would be to have two applications. The service side (written basically as a console application) and the client/monitoring GUI side. The service would use some remote connectivity (when I did this I used Named Pipes) to communicate with the client/monitoring application. Either should be able to run without the other, and certainly the service should be able to run with out the client.