Web Socket Server on Windows Tablets

Question

Hi,

We are developing a WIndows STore app for windows 8 to be deployed on a WIndows 8 tablet. 

Please give ur views on below.

1. We have libwebsocket server being compiled for windows 8 . Hope, we can directly execute this executable server on Windows 8 tablets.

2. Hope we can establish a seamless websocket communication to this server from a javascript /html5 code running as a windows store app .

3. please note both of the above are running on same tablet.

4. Hope there are no security restrictions with this.

Thanks

Answer 1

Hi,

There is a need to develop a server which will act as a socket listener for incoming requests. I have developed this on a windows 8 desktop machine.

The requests would come from a windows store app's Javascript (web socket requests). The windows store app would be deployed on a windows tablet (running windows 8 pro Intel).

1. How can I drop the server executable directly on the windows 8 pro tablet and run it ?

2. Is this possible on windows tablets?

Thanks

Answer 2

Hi Sankarshana,

The overall scenario is not supported. Windows Store apps cannot depend on or communicate with services on the localhost.

1. How can I drop the server executable directly on the windows 8 pro tablet and run it ?

The same way you drop the server executable on any other Windows 8 Pro system.

2. Is this possible on windows tablets?

It depends on what you mean by "this". Being on a tablet form factor is generally irrelevant. Windows 8 Pro tablets are Windows 8 Pro systems and can do anything that any other Windows 8 Pro system can do.

Windows Store apps cannot connect to web services on the localhost (an exception can be created for testing and debugging, but the app cannot create an exception for production).

--Rob

Answer 3

Any responses to this please

Answer 4

Hi Sankarshana,

The overall scenario is not supported. Windows Store apps cannot depend on or communicate with services on the localhost.

1. How can I drop the server executable directly on the windows 8 pro tablet and run it ?

The same way you drop the server executable on any other Windows 8 Pro system.

2. Is this possible on windows tablets?

It depends on what you mean by "this". Being on a tablet form factor is generally irrelevant. Windows 8 Pro tablets are Windows 8 Pro systems and can do anything that any other Windows 8 Pro system can do.

Windows Store apps cannot connect to web services on the localhost (an exception can be created for testing and debugging, but the app cannot create an exception for production).

--Rob

Thanks Rob.

My scenario is, WIndows store apps (javascript) to connect to a websocket server thats running locally (through localhost).. is this also not allowed?

Answer 5

Windows Store apps cannot depend on or communicate with services on the localhost.

Answer 6

Windows Store apps cannot depend on or communicate with services on the localhost.

Thanks, what if those services are spawned from a windows store app itself ??

Like, an installation of windows store app will spawn a parallel execution entity (a thread for example) in which the server is running on a different port? This will not violate the sandboxing...

Answer 7

Yes, an app can communicate with itself. If your "service" is part of the app itself then you are fine.

--Rob

Answer 8

Yes, an app can communicate with itself. If your "service" is part of the app itself then you are fine.

--Rob

thanks Rob..

Answer 9

Although note that the service must be compatible with the app store -- that is, it can only use the allowed set of APIs, etc.  This might be a problem for your libwebsocket server

My team is always interested in how people are using WebSockets.  What kind of app are you using?  And what websocket feature was the most compelling feature?

---

Network Developer Experience Team (Microsoft)

Answer 10

Thanks for the details. Let me give some more details here and I request ur team to point out any issues / differences..

1. When I say spinning off a service from windows store app (javascript based app), what I mean is that,

I will mostly have a winRT_C++ component which will expose let's say a method called "execute". This method will be called from javascript .

2. When this method (assync method) is called, the implementation of this method will create a native thread 

and will open a websocket server on that thread .

3. This thread will be listening to websocket connections.

4. Javascript will later (from other button clicks) will post requests to this websocket server thread and keep going.

do u see any issues here.? 

I understand that, the thread must do things that are withing allowed limits as per windows store app. But, the thread function is a C++ code which will probably create some locla websocket sockets and will wait on it etc...

Thanks

Answer 11

Thanks again.

I find it weird and wondering why and how I am able to do the below.

Development and testing Environment: Windows 8 Machine with VS 2012 -Express for WIndows 8 installed.

1. I have created a javascript Project (Phone gap based) which renders some HTML5 UI.

2. I have developed a desktop plain C++ application which when executed, will start a WebSocket Server (through Libwebsockets) and will wait for connections.

3. I executed the exe seperately.

4. I run the Javascript Project through VS-2012 IDE in "SImulator " mode (because I dont have a Surface tablet yet).

5. This Javascript will connect to the WebSocket server and will get some data and will display.

This whole thing works in simulator mode or as an "Installed APP" when run through the VS-2012 on a surface tablet. (Pls note , VS is installed on a surface tablet).

QUestion is, why the javascript based windows store app is able to connect to the WebSocket Server which is deployed as an EXE? WHy the restrictions are not applying?

I really want to get into the details to once for all clear out this.

Thanks..

Answer 12

Thanks for the details. Let me give some more details here and I request ur team to point out any issues / differences..

1. When I say spinning off a service from windows store app (javascript based app), what I mean is that,

I will mostly have a winRT_C++ component which will expose let's say a method called "execute". This method will be called from javascript .

2. When this method (assync method) is called, the implementation of this method will create a native thread 

and will open a websocket server on that thread .

3. This thread will be listening to websocket connections.

4. Javascript will later (from other button clicks) will post requests to this websocket server thread and keep going.

do u see any issues here.? 

I understand that, the thread must do things that are withing allowed limits as per windows store app. But, the thread function is a C++ code which will probably create some locla websocket sockets and will wait on it etc...

Thanks

Network Developer Exp Team,

any replies to this pls.

Answer 13

Thanks again.

I find it weird and wondering why and how I am able to do the below.

Development and testing Environment: Windows 8 Machine with VS 2012 -Express for WIndows 8 installed.

1. I have created a javascript Project (Phone gap based) which renders some HTML5 UI.

2. I have developed a desktop plain C++ application which when executed, will start a WebSocket Server (through Libwebsockets) and will wait for connections.

3. I executed the exe seperately.

4. I run the Javascript Project through VS-2012 IDE in "SImulator " mode (because I dont have a Surface tablet yet).

5. This Javascript will connect to the WebSocket server and will get some data and will display.

This whole thing works in simulator mode or as an "Installed APP" when run through the VS-2012 on a surface tablet. (Pls note , VS is installed on a surface tablet).

QUestion is, why the javascript based windows store app is able to connect to the WebSocket Server which is deployed as an EXE? WHy the restrictions are not applying?

I really want to get into the details to once for all clear out this.

Thanks..

Network Developer exp team, Rob

any replies to this pls

Thx

Answer 14

The restriction is not in place for projects in development.  The restrictions go into place when deployed.

---

Matt Small - Microsoft Escalation Engineer - Forum Moderator
If my reply answers your question, please mark this post as answered.

NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

Answer 15

Matt,

thanks for clarification on restriction being ON at deployment time and not at development time.

I request (if possible), pls publish this info somewhere in MSDN so that, people will not get confused. Thanks and appreciate it..

Answer 16

See the Troubleshooting and debugging network connections documentation.

--Rob