SignalR is a viable alternative to Socket.IO and Node.js. There are other reasons to use javascript on the server however.

1. It flattens the stack. Almost any website these days has to have javascript on the browser, and if you use it on the server as well, you can cut one language out of the batch that you&#39;ll have to be proficient in. 

2. Message passing is very natural. JSON Everywhere! Especially combined with a document database which uses JSON, all message passing just becomes JSON objects. This makes reduces the amount of message brokering that has to happen throughout the system.

3. It&#39;s not Microsoft. I personally love what Microsoft has done for the development community. They make fantastic tools and one of the best frameworks and languages around. That being said, some people just love to hate Microsoft.

4. Cost. There are many good ways to get Microsoft tools for free or very cheap (Express editions and Biz Spark). There is still a higher cost associated with working with Microsoft tools. I believe this cost is worth the productivity gains in most instances, but not everyone agrees.

In addition to the above, there is still the story going around that you can&#39;t scale long polling requests on IIS due to the threading model. This has some truth to it, but with [good code design][1], and some server tweaks, you can mostly get around these problems. 


  [1]: http://msdn.microsoft.com/en-us/magazine/cc163463.aspx

Can a CSS `px` be a fraction? Is it allowed by the standards? And if so, do the major browsers support it?

Let&#39;s back the answers up with documentation, folks.

Can a CSS pixel be a fraction?

Being totally new into node.js environment and philosophy i would like answers to few questions. I had downloaded the node.js for windows installer and also node package manager.Windows Cmd prompt is being currently used for running nodejs apps.

1. cls clears the command window or errors in command prompt. Is there a equivalent for node.js ? console.clear does not exist ;( or does it in some other form?

2. I created a server through this code below

        var http = require(&quot;http&quot;);
        http.createServer(function (request, response) {
        	response.writeHead(200, {
        		&quot;Content-Type&quot;: &quot;text/html&quot;
        	});
        	response.write(&quot;Hello World&quot;);
        	console.log(&quot;welcome world&quot;)response.end();
        }).listen(9000, &quot;127.0.0.1&quot;);

i changed the code to below and refreshed the browser to find that content type does not change, how do i get to see the changes?

    var http = require(&quot;http&quot;);
    http.createServer(function(request, response) {
      response.writeHead(200, {&quot;Content-Type&quot;: &quot;text/plain&quot;});
      response.write(&quot;Hello World&quot;);
      console.log(&quot;welcome world&quot;)
      response.end();
    }).listen(9000,&quot;127.0.0.1&quot;);

Node.Js on windows - How to clear console

Since I&#39;ve known about Node.js, I&#39;ve always been a fan of it. But today I found about [SignalR][1], which provides an alternative asynchronous - scalable - realtime model for ASP.NET. 

As far as I know, the main advantage of Node.js over SignalR is sharing code between client-server (another advantage should be that it is cross-platform), and the main advantage of SignalR is a much more mature framework and far better tool (IDE) support. So I wonder: if SignalR is here, do we need Node.js on Windows anymore? Are there any advantages of Node.js I don&#39;t know?


  [1]: https://github.com/SignalR/SignalR

Nodejs vs SignalR: why do we need server-side javascript?

<p>Since I've known about Node.js, I've always been a fan of it. But today I found about <a href="https://github.com/SignalR/SignalR" target="_blank" rel="noopener noreferrer">SignalR</a>, which provides an alternative asynchronous - scalable - realtime model for ASP.NET.</p>
<p>As far as I know, the main advantage of Node.js over SignalR is sharing code between client-server (another advantage should be that it is cross-platform), and the main advantage of SignalR is a much more mature framework and far better tool (IDE) support. So I wonder: if SignalR is here, do we need Node.js on Windows anymore? Are there any advantages of Node.js I don't know?</p>


I use a `FileUploader` control in my application. I want to save a file to a specified folder. If this folder does not exist, I want to first create it, and then save my file to this folder.  If the folder already exists, then just save the file in it.

How can I do this?


If a folder does not exist, create it

How can I check if directory `C:/` contains a folder named `MP_Upload`, and if it does not exist, create the folder automatically?

I am using Visual&amp;nbsp;Studio&amp;nbsp;2005 C#.


Check if a folder exist in a directory and create them using C#

I have an object model that looks like this:

    public MyObjectInJson
    {
       public long ObjectID {get;set;}
       public string ObjectInJson {get;set;}
    }

The property `ObjectInJson` is an already serialized version an object that contains nested lists. For the moment, I&#39;m serializing the list of `MyObjectInJson` manually like this:

    StringBuilder TheListBuilder = new StringBuilder();
    
    TheListBuilder.Append(&quot;[&quot;);
    int TheCounter = 0;
    
    foreach (MyObjectInJson TheObject in TheList)
    {
      TheCounter++;
      TheListBuilder.Append(TheObject.ObjectInJson);
    
      if (TheCounter != TheList.Count())
      {
        TheListBuilder.Append(&quot;,&quot;);
      }
    }
    TheListBuilder.Append(&quot;]&quot;);
    
    return TheListBuilder.ToString();

I wonder if I can replace this sort of dangerous code with `JavascriptSerializer` and get the same results.
How would I do this?

Serializing a list to JSON

I am loading an aspx web page in an iframe. The content in the Iframe can be of more height than the iframe&#39;s height. The iframe should not have scroll bars.

I have a wrapper `div` tag inside the iframe which basically is all the content.  I wrote some jQuery to make the resize happen :

    $(&quot;#TB_window&quot;, window.parent.document).height($(&quot;body&quot;).height() + 50);
where
`TB_window` is the div in which the `Iframe` is contained.

`body` - the body tag of the aspx in the iframe.

This script is attached to the iframe content. I am getting the `TB_window` element from the parent page. While this works fine on Chrome, but the TB_window collapses in Firefox. I am really confused/lost on why that happens.

make iframe height dynamic based on content inside- JQUERY/Javascript

Can I convert Class into Dictionary&amp;lt;string, string&gt;?

In Dictionary I want my class properties as *keys* and value of particular a property as the *value*.

Suppose my class is

    public class Location
    {
        public string city { get; set; }
        public string state { get; set; }
        public string country { get; set;
    }

Now suppose my data is

    city = Delhi
    state = Delhi
    country = India

Now you can understand my point easily!

I want to make a Dictionary! That dictionary should be like:

    Dictionary&lt;string,string&gt; dix = new Dictionary&lt;string,string&gt; ();
    dix.add(&quot;property_name&quot;, &quot;property_value&quot;);

I can get the value! But how can I get property names (**not value**)?

What should I code to create it dynamic? That should work for every class which I want.

You can understand this question as:

How can I get a list of properties from particular class?

&lt;sub&gt;Now again I am explaining one of my eagernesses about Dictionary! This question popuped in my mind from answer of my [previous question][1]!!&lt;/sub&gt;

  [1]: https://stackoverflow.com/q/9209272/1162201






How can I convert a class into Dictionary&lt;string,string&gt;?

Process.platform returns &quot;win32&quot; for Windows. On Windows a user&#39;s home directory might be C:\Users\[USERNAME] or C:\Documents and Settings\[USERNAME] depending on which version of Windows is being used. On Unix this isn&#39;t an issue.

Node.js - Find home directory in platform agnostic way

I could do with some help on my REST API. I&#39;m writing a Node.js app which is using Express, MongoDB and has Backbone.js on the client side. I&#39;ve spent the last two days trying to work out all of this and not having much luck. I&#39;ve already checked out:

 - https://stackoverflow.com/questions/2676241/securing-a-rest-api
 - https://stackoverflow.com/questions/4574868/securing-my-rest-api-with-oauth-while-still-allowing-authentication-via-third-pa
 - http://www.thebuzzmedia.com/designing-a-secure-rest-api-without-oauth-authentication/
 - http://tesoriere.com/2011/10/10/node.js-getting-oauth-up-and-working-using-express.js-and-railway.js/

I want to keep my backend and frontend as separate as possible so I thought about using a carefully designed REST API would be good. My thinking is that if I ever get round to developing an iPhone app (or something else like that), it could use the API to access data.

BUT, I want this to be secure. A user has logged into my web app and I want to ensure my API is secure. I read about OAuth, OAuth 2.0, OpenID, Hmac, hashes etc... I want to avoid using external logging in (Facebook/Twitter/etc) I want the registering and logging in to be on my app/server.

...but I&#39;m still confused here. Maybe it&#39;s late at night or my brain is just fried, but I could really do with some steps on what to do here. What are the steps for me to create a secure API?

Any help, any information, any examples, steps or anything would be great. Please help!


Securing my Node.js app&#39;s REST API?

I have my application (node.js) deployed on a VPS (linux). I&#39;m using git hub as a repository. How can I deploy the application automatically, on git push ?

How can I automatically deploy my app after a git push ( GitHub and node.js)?

Is there a way to get the version set in `package.json` in a nodejs app? I would want something like this

    var port = process.env.PORT || 3000
    app.listen port
    console.log &quot;Express server listening on port %d in %s mode %s&quot;, app.address().port, app.settings.env, app.VERSION


Is there a way to get version from package.json in nodejs code?

I&#39;m testing out an app (hopefully to run on heroku, but am having issues locally as well).  It&#39;s giving me an EACCES error when it runs http.Server.listen() - but it only occurs on some ports.

So, locally I&#39;m running:


    joe@joebuntu:~$ node
    &gt; var h = require(&#39;http&#39;).createServer();
    &gt; h.listen(900);
    Error: EACCES, Permission denied
        at Server._doListen (net.js:1062:5)
        at net.js:1033:14
        at Object.lookup (dns.js:132:45)
        at Server.listen (net.js:1027:20)
        at [object Context]:1:3
        at Interface.&lt;anonymous&gt; (repl.js:150:22)
        at Interface.emit (events.js:42:17)
        at Interface._onLine (readline.js:132:10)
        at Interface._line (readline.js:387:8)
        at Interface._ttyWrite (readline.js:564:14)


I don&#39;t have anything running on port 900 (or any of the other 20 ports I&#39;ve tried), so this should work.  The weird part is that it **does** work on some ports.  For instance, port 3000 works perfectly.

What would cause this?  

Update 1:
---------
I figured out that on my local computer, the EACCES error is coming because I have to run node as root in order to bind to those certain ports.  I don&#39;t know why this happens, but using sudo fixes it.  However, this doesn&#39;t explain how I would fix it on Heroku.  There is no way to run as root on Heroku, so how can I listen on port 80?



Node.js EACCES error when listening on most ports

I tried the sample provided within the documentation of the [requests library][1] for python.

With `async.map(rs)`, I get the response codes, but I want to get the content of each page requested. This, for example, does not work:

    out = async.map(rs)
    print out[0].content




  [1]: http://docs.python-requests.org/en/latest/user/advanced/#asynchronous-requests

Asynchronous Requests with Python requests

First, this is a very specific case of doing it the wrong way on-purpose to retrofit an asynchronous call into a very synchronous codebase that is many thousands of lines long and time doesn&#39;t currently afford the ability to make the changes to &quot;do it right.&quot; It hurts every fiber of my being, but reality and ideals often do not mesh. I know this sucks.

OK, that out of the way, how do I make it so that I could:

    function doSomething() {

      var data;

      function callBack(d) {
        data = d;
      }

      myAsynchronousCall(param1, callBack);

      // block here and return data when the callback is finished
      return data;
    }

The examples (or lack thereof) all use libraries and/or compilers, both of which are not viable for this solution. I need a concrete example of how to make it block (e.g. NOT leave the doSomething function until the callback is called) WITHOUT freezing the UI. If such a thing is possible in JS.

Call An Asynchronous Javascript Function Synchronously

I am new to asynchronous programming with the `async` modifier. I am trying to figure out how to make sure that my `Main` method of a console application actually runs asynchronously.

    class Program
    {
        static void Main(string[] args)
        {
            Bootstrapper bs = new Bootstrapper();
            var list = bs.GetList();
        }
    }

    public class Bootstrapper {

        public async Task&lt;List&lt;TvChannel&gt;&gt; GetList()
        {
            GetPrograms pro = new GetPrograms();

            return await pro.DownloadTvChannels();
        }
    }

I know this is not running asynchronously from &quot;the top.&quot; Since it is not possible to specify the `async` modifier on the `Main` method, how can I run code within `main` asynchronously?

Can&#39;t specify the &#39;async&#39; modifier on the &#39;Main&#39; method of a console app

I&#39;m trying to understand how a portion of backbone.js works. I have to fetch a collection of models once the app begins. I need to wait until fetch is complete to render each view. 
I&#39;m not 100% sure the best approach to take in this instance.

    var AppRouter = Backbone.Router.extend({
        routes: {
            &quot;&quot;: &quot;home&quot;,
            &quot;customer/:id&quot;: &quot;customer&quot; 
        },

        home: function () {
            console.log(&quot;Home&quot;);
        },

        customer: function (id) {
            if (this.custromers == null)
                this.init();

            var customer = this.customers.at(2); //This is undefined until fetch is complete. Log always says undefined.
            console.log(customer);
        },

        init: function () {
            console.log(&quot;init&quot;);
            this.customers = new CustomerCollection();
            this.customers.fetch({
                success: function () {
                    console.log(&quot;success&quot;); 
                    // I need to be able to render view on success.
                }
            });
            console.log(this.customers);
        }
    });    

How to wait to render view in backbone.js until fetch is complete?

The nodejs async module: https://github.com/caolan/async provides 2 similar methods, `async.waterfall` and `async.series`.

What is the difference between them?

What is the difference between async.waterfall and async.series

I&#39;ve been searching and reading up on SignalR recently and, while I see a lot of explanation of what the difference is between Hubs and Persistent Connections I haven&#39;t been able to get my head around the next level, which is why would I choose one approach over the other?

SignalR: Why choose Hub vs. Persistent Connection?

I&#39;ve seen https://stackoverflow.com/questions/9307675/signalr-vs-html5-websockets-for-asp-net-mvc-chat-application but it doesn&#39;t 100% answer my question as it&#39;s based around HTML5 WebSockets, which Microsoft may have extended upon in .NET 4.5 with their WebSocket object.

I&#39;m wondering if the WebSocket feature does actually do the same as SignalR and fall back to long polling when WebSockets aren&#39;t available? Surely Microsoft would implement the same technology as SignalR in their approach to this technology?

Edit:

For anyone else wondering about this, I found this comment the most helpful to understand the scenario and why I&#39;ll be using SignalR:

&gt; Well, they are not really. Up until now IIS and ASP.NET didn&#39;t have
&gt; anything built in that supported WebSockets so SignalR project had to
&gt; build it themselves. Now that Microsoft is providing the plumbing
&gt; SignalR could easily switch to using Microsoft&#39;s implementation,
&gt; either in addition to or instead of their own. SignalR is an
&gt; abstraction over implementation details, WebScockets class is the
&gt; implementation detail

.NET 4.5 WebSockets vs SignalR

I currently have a TCP server application written in .Net that receives and submits messages to clients. I am looking at building a web application so need the communication layer.

I have built a Node.JS + Socket.IO app which connects to my TCP server and then pushes communication to the web application and all works fine.

I have just read about SignalR as an alternative to keep it in the .Net stack.

However I have also found that I could write a C# Websocket Server, a basic demo [here][1]

I assume that this basic server is what SignalR is but obviously with a lot more functionality in it?

What I&#39;m trying to decide is do I just append my current TCP application with a Websocket server or do I go down a separate SignalR or Node.js route?  Out of interest how does a SignalR application run, is it as a Windows service, console app or IIS service?

  [1]: https://stackoverflow.com/questions/2211898/c-sharp-web-socket-server

Node.Js + Socket.IO vs SignalR vs C# WebSocket Server

Is there a small example of a console or winform app using signalR to send a message to a .net hub?. I have tried the .net examples and have looked at the wiki but it is not making sense to me the relationship between the hub(.net) and client(console app) (could not find an example of this). Does the app just need the address and name of hub to connect?.

If someone could provide a small tidbit of code showing the app connecting to a hub and sending &quot;Hello World&quot; or something that the .net hub receives?. 

PS. I have a standard hub chat example which works well , if I try to assign a hub name in Cs to it , it stops working i.e [HubName(&quot;test&quot;)] , do you know the reason for this?.

Thanks.


Current Console app Code.

    static void Main(string[] args)
    {
        //Set connection
        var connection = new HubConnection(&quot;http://localhost:41627/&quot;);
        //Make proxy to hub based on hub name on server
        var myHub = connection.CreateProxy(&quot;chat&quot;);
        //Start connection
        connection.Start().ContinueWith(task =&gt;
        {
            if (task.IsFaulted)
            {
                Console.WriteLine(&quot;There was an error opening the connection:{0}&quot;, task.Exception.GetBaseException());
            }
            else
            {
                Console.WriteLine(&quot;Connected&quot;);
            }
        }).Wait();

        //connection.StateChanged += connection_StateChanged;
         
        myHub.Invoke(&quot;Send&quot;, &quot;HELLO World &quot;).ContinueWith(task =&gt; {
            if(task.IsFaulted)
            {
                Console.WriteLine(&quot;There was an error calling send: {0}&quot;,task.Exception.GetBaseException());
            }
            else
            {
                Console.WriteLine(&quot;Send Complete.&quot;);
            }
        });
     }

Hub Server. (different project workspace)

    public class Chat : Hub
    {
        public void Send(string message)
        {
            // Call the addMessage method on all clients
            Clients.addMessage(message);
        }
    }



Info Wiki for this is &lt;http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-net-client&gt;

SignalR Console app example

I have been looking at SignalR from last few days. Using this I have created an Admin Dashboard to get realtime information about a database table. Basically this table gets populated by may different users from various applications. It has come out well. These updates are possible only when there is persistent connection between client Broswer and WebServer. I have few doubts before deploying this app in production.

I understand that SignalR first checks WebSockets then looks for Long Polling based on there availability between client and server. No matter what it uses, there will be a connection open between client and server. 

My question is how does it perform in scenario where more users are connected to the same server for example  100,000 admins are connected at same time. Does IIS has any limitations on number of persistent connections it can open at one point? If so can we configure to that to max value and what wud be that value.

Sorry if it is rookie question

ASP.NET MVC3 &amp; IIS 7 are used for development.

Content Type	Original Author	Original Content on Stackoverflow
Question	Quan Mai	View Question on Stackoverflow
Solution 1 - asp.net	Timothy Strimple	View Answer on Stackoverflow

Nodejs vs SignalR: why do we need server-side javascript?

asp.net Problem Overview

asp.net Solutions

Solution 1 - asp.net

Node.Js on windows - How to clear console

Can a CSS pixel be a fraction?

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