**No**

Already answered here for more details: https://stackoverflow.com/questions/4118272/do-websockets-allow-for-p2p-browser-to-browser-communication

**Update**:

The [WebRTC](http://www.webrtc.org) protocol and API is making rapid progress and allows a Data Channel to be established between two peers (you still may need a STUN/TURN server for the initial NAT traversal and setup).

From past to future:  Pick your implementation.

 - Most modern browsers support peer to proxy to peer using [Websockets][1].
 - Peer to peer is only available using certain browsers plug-ins for example [Opera Unite][2] and [FireFox Pow][3].  
 - Major browsers are in the process of implementing [WebRTC][4] which will allow peer to peer.


  [1]: http://www.websocket.org/
  [2]: https://stackoverflow.com/questions/9286848/peer-to-peer-file-sharing-with-web-sockets
  [3]: https://addons.mozilla.org/en-US/firefox/addon/pow-plain-old-webserver/
  [4]: http://www.webrtc.org/

If you just don&#39;t want to implement server your self you can use https://httprelay.io . No additional libraries required, all communication based on simple AJAX calls.

I have a tableView that I&#39;m inserting rows into at the top.

Whilst I&#39;m doing this I want the current view to stay completely still, so the rows only appear if you scroll back up.

I&#39;ve tried saving the current position of the underlying UIScrollview and resetting the position after the rows have been inserted but this results in a judder, up and down, although it does end up back in the same place.

Is there a good way of achieving this ?

Update: I am using beginUpdate, then insertRowsAtIndexPath, endUpdates. There is no reloadData call.

scrollToRowAtIndexPath jumps to the top of the current cell (saved before adding rows).

The other approach I tried, which ends up in **exactly** the right pace, but with a judder is.

    save tableView currentOffset. (Underlying scrollView method)
    Add rows (beginUpdates,insert...,endUpdates) 
    reloadData ( to force a recalulation of the scrollview size )
    Recalculate the correct new offset from the bottom of the scrollview
    setContentOffset (Underlying scrollview method)

Trouble is the reloadData causes the scrollview/tableview to start scrolling briefly, then the setContentOffset returns it to the correct place.

Is there a way of getting a tableView to work out it&#39;s new size without starting display ?

Wrapping the whole thing in a beginAnimation commitAnimation doesn&#39;t help much either.

Update 2: This can clearly be done - see the offical twitter app for one when you pull down for updates.

Keep uitableview static when inserting rows at the top

This doesn&#39;t seem easy.  Basically, I add `QPushButton`s through a function to a layout, and when the function executes, I want to clear the layout first (removing all `QPushButton`s and whatever else is in there), because more buttons just get appended to the `scrollview`.

header

    QVBoxLayout* _layout;

cpp

    void MainWindow::removeButtonsThenAddMore(const QString &amp;item) {
    
    //remove buttons/widgets
    
    QVBoxLayout* _layout = new QVBoxLayout(this);

    QPushButton button = new QPushButton(item);
    _layout-&gt;addWidget(button);
    
    QPushButton button = new QPushButton(&quot;button&quot;);
    _layout-&gt;addWidget(button);
    
    QWidget* widget = new QWidget();
    widget-&gt;setLayout(_layout);
    
    QScrollArea* scroll = new QScrollArea();
    scroll-&gt;setWidget(widget);
    scroll-&gt;show();
    
    }



Qt - remove all widgets from layout?

Using HTML5 Websockets, can I open a socket directly between 2 clients (browsers) (assuming I know their IP addresses and there are no NAT traversal issues). I want to send some data directly from one browser to another browser, essentially creating a P2P network. Everything I&#39;ve read so far on the web, websockets are all used to communicate between client and server, but nothing about client to client.


Can HTML5 Websockets connect 2 clients (browsers) directly without using a server? (P2P)

<p>Using HTML5 Websockets, can I open a socket directly between 2 clients (browsers) (assuming I know their IP addresses and there are no NAT traversal issues). I want to send some data directly from one browser to another browser, essentially creating a P2P network. Everything I've read so far on the web, websockets are all used to communicate between client and server, but nothing about client to client.</p>


I have several [PHP][1] pages echoing out various things into [HTML][2] pages with the following code.

    &lt;meta http-equiv=&quot;Content-type&quot; content=&quot;text/html; charset=utf-8&quot; /&gt;

However, when I validate using the [W3C validator][3] it comes up with:

&gt; The character encoding specified in the HTTP header (iso-8859-1) is different from the value in the &lt;meta&gt; element (utf-8).

I am quite new to PHP, and I was wondering if I could and should change the header for the PHP files to match the HTML files.

  [1]: http://en.wikipedia.org/wiki/PHP
  [2]: http://en.wikipedia.org/wiki/HTML
  [3]: https://en.wikipedia.org/wiki/W3C_Markup_Validation_Service


How to set HTTP header to UTF-8 using PHP which is valid in W3C validator

I&#39;m working with PHP, and I&#39;m making an action page which a form posts to. The page checks for errors, then if everything is fine, it redirects them to the page where the data has been posted. If not, I need to to redirect them back to the page they were at with an error and the POST variables. Here is the gist of how it works.

The HTML would look like this...

    &lt;form name=&quot;example&quot; action=&quot;action.php&quot; method=&quot;POST&quot;&gt;
      &lt;input type=&quot;text&quot; name=&quot;one&quot;&gt;
      &lt;input type=&quot;text&quot; name=&quot;two&quot;&gt;
      &lt;input type=&quot;text&quot; name=&quot;three&quot;&gt;
      &lt;input type=&quot;submit&quot; value=&quot;Submit!&quot;&gt;
    &lt;/form&gt;

action.php would look like this...

    if(error_check($_POST[&#39;one&#39;]) == true){
        header(&#39;Location: form.php&#39;);
        // Here is where I need the data to POST back to the form page.
    } else {
        // function to insert data into database
        header(&#39;Location: posted.php&#39;);
    }

In the case of an error, I need it to POST back to the first page.
I can&#39;t use GET, because the input will be too large.
I don&#39;t want to use SESSION, if possible.
Is this possible? 

PHP header() redirect with POST variables

I want to submit a form. But I am not going the basic way of using a input button with submit type but a **a** link. 

The image below shows why. I am using image links to save/submit the form. Because I have standart css markup for image links I don&#39;t want to use input submit buttons.

I tried to apply *onClick=&quot;document.formName.submit()&quot;* to the a element but I would prefer a html method.

![alt text][1]

Any ideas?

  [1]: http://i.stack.imgur.com/QKAlE.png

Use a normal link to submit a form

I am trying to create a canvas element that takes up 100% of the width and height of the viewport. 

You can see in my example [here][1] that is occurring, however it is adding scroll bars in both Chrome and FireFox.  How can I prevent the extra scroll bars and just provide exactly the width and height of the window to be the size of the canvas?


  [1]: http://jsfiddle.net/mqFdk/

HTML5 Canvas 100% Width Height of Viewport?

Is there any ways to populate all of the input from certain form?
let say, some thing like this:

    &lt;form id=&quot;unique00&quot;&gt;
      &lt;input type=&quot;text&quot; name=&quot;whatever&quot; id=&quot;whatever&quot; value=&quot;whatever&quot; /&gt;
      &lt;div&gt;
        &lt;input type=&quot;checkbox&quot; name=&quot;whatever&quot; id=&quot;whatever&quot; value=&quot;whatever&quot; /&gt;
      &lt;/div&gt;
      &lt;table&gt;&lt;tr&gt;&lt;td&gt;
        &lt;input type=&quot;hidden&quot; name=&quot;whatever&quot; id=&quot;whatever&quot; value=&quot;whatever&quot; /&gt;
        &lt;input type=&quot;submit&quot; value=&quot;qweqsac&quot; /&gt;
      &lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;
    &lt;/form&gt;
    &lt;form id=&quot;unique01&quot;&gt;
      &lt;div&gt;
        &lt;input type=&quot;text&quot; name=&quot;whatever&quot; id=&quot;whatever&quot; value=&quot;whatever&quot; /&gt;
        &lt;input type=&quot;checkbox&quot; name=&quot;whatever&quot; id=&quot;whatever&quot; value=&quot;whatever&quot; /&gt;
      &lt;/div&gt;
      &lt;table&gt;&lt;tr&gt;&lt;td&gt;
        &lt;input type=&quot;hidden&quot; name=&quot;whatever&quot; id=&quot;whatever&quot; value=&quot;whatever&quot; /&gt;
      &lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;
      &lt;select&gt;blah...&lt;/select&gt;
      &lt;input type=&quot;submit&quot; value=&quot;qweqsac&quot; /&gt;
    &lt;/form&gt;
    etc forms... forms...

*note: each form might have a different amount of input and type and also different html structure

so is there any way to populate the input from certain form id? eg if i click submit button from certain form id, then jquery will populate for me all of the input within those form id.
currently what i&#39;m doing is like this:

    $(&quot;form&quot;).submit(function(){ return validateForm($(this)) });
    function validateForm(form){
	var retVal = true;
	var re;
	$.each(form.serializeArray(), function(i, field) {
	  var input = $(&#39;input[name=&#39;+field.name+&#39;]&#39;);
	  field.value = $.trim(field.value);
	  switch(field.name){
	    case &quot;name&quot; :
            and another cases...
          }
        })
     }

that was work,
but in that case, i only get the field.name and field.value, and actually what i want is, i want a jquery object for each input element, so i can access their css, id, name, and even animate those input element

is there any way for this?

please let me know and thank you in advance!
AnD

jquery get all input from specific form

How can I write a website using *HTML5*, *CSS* and *JavaScript* on client side that will allow **direct tcp/ip connection between the client browsers once the page is loaded**.

I need to do this to to reduce latency since the site will require that the input from one of the users to be transmitted to the other user as soon as possible so sending data from client A to Server and then to client B is not a good option.

I read previous posts on this subject but there were no working solution/examples available that I could find. From what i read the direct connection between clients can be made using plugins like Silverlight, Java or Flash.

Is there any solution that would not require plugins? I would like to use only JavaScript.

How can I make a browser to browser (peer to peer) connection?

I can only get [this SDK sample of PeerChannel SecureChat](http://msdn.microsoft.com/en-us/library/ms751534%28v=vs.90%29.aspx) to work in the following scenarios in a basic home network:

 * Locally among instances running on the same machine, or
 * Among Windows 7 machines

I *cannot* get this to work between my Windows Server 2008 R2 and any other machine (no exceptions are thrown, but the nodes never find each other and thus don&#39;t go &quot;online&quot;).  I CAN ping the IPv6 addresses among all machines. The executable has a firewall exception rule, but I have also tried disabling the Windows 2008 firewall completely.  The PRNP Service is running.

 1. **Is it possible to get it working?  How?**

 1. **Does it work on YOUR 2008 machine?**

My best guess:  I notice that in the Windows 7 machines, the &quot;Peer Networking Grouping&quot; and &quot;Peer Networking Identity Manager&quot; services are present.  The &quot;Peer Networking Grouping&quot; service&#39;s description there and online talks specifically about enabling multi-party conversations, but related to Home Groups.  This service is missing in the Windows Server machine.

So, I suspect the missing service as the reason that the SecureChat sample won&#39;t work on the Windows Server machine, but I don&#39;t understand why Microsoft would lock out Peer Channel from working on the Server product. Could this be the reason?

Thanks!

Getting MSDN PeerChannel &quot;SecureChat&quot; running on Windows Server 2008 R2

I started to explore the option of connecting with other using a p2p connection, so I coded a simple socket program in JAVA for android devices in which the users can share simple messages p2p (I didn&#39;t have any idea about NAT then). I got to know about NAT, so I now need to establish a TCP connection with another user which uses a server for discovery but payload is transferred p2p. I have also looked at XMPP(a very good and detailed explanation of how protocol works is [here][1]) and UPnP but I dont know how to implement them.

Another interesting question that arises is of BitTorrent because they can work on any device and even behind a NAT. I am not able to get any explanation of how BitTorrent works.

I have researched a lot but I am stuck.

My questions are:

1. A detailed explanation of BitTorrent(like [here][1], not how torrents work) and how is it able to work around NAT ?
2. Is there a way to make a NAT entry programmatically ?
3. Is socket programming sufficient for p2p ?
3. How difficult is it to create your own protocol and how can I build one ?
4. If two devices D1 and D2 want to communicate p2p and they know each other&#39;s IP. D1 sends a request to D2 and that can&#39;t get through the D2&#39;s NAT, but there should be an entry created in D1&#39;s NAT. So when D2 tries to send something D1&#39;s NAT should discover an entry with D2&#39;s IP. Then why is the packet not allowed by it ?


  [1]: http://ceit.uq.edu.au/content/how-xmpp-works-step-step

Connecting P2P over NAT?

Looks like it&#39;s easy to add custom HTTP headers to your websocket client with any HTTP header client which supports this, but I can&#39;t find how to do it with the web platform&#39;s `WebSocket` API. 

Anyone has a clue on how to achieve it? 

    var ws = new WebSocket(&quot;ws://example.com/service&quot;);

Specifically, I need to be able to send an HTTP Authorization header.

HTTP headers in Websockets client API

I&#39;d like to know if it&#39;s possible to broadcast on different websocket &quot;connections&quot; running from the same &lt;a href=&quot;https://github.com/miksago/node-websocket-server&quot;&gt;node-websocket-server&lt;/a&gt; app instance. Imagine a chatroom server with multiple rooms, only broadcasting messages to the participants specific to each room, on a single node.js server process. I&#39;ve successfully implemented a one-chatroom-per-process solution, but I want to take it to the next level.

node-websocket-server: possible to have multiple, separate &quot;broadcasts&quot; for a single node.js process?

I&#39;m working with socket.io and node.js and until now it seems pretty good, but I don&#39;t know how to send a message from the server to an specific client, something like this:

    client.send(message, receiverSessionId)

But neither the `.send()` nor the `.broadcast()` methods seem to supply my need.

What I have found as a possible solution, is that the `.broadcast()` method accepts as a second parameter an array of SessionIds to which not send the message, so I could pass an array with all the SessionIds connected at that moment to the server, except the one I wish send the message, but I feel there must be a better solution.

Any ideas?

Send message to specific client with socket.io and node.js

I&#39;m writing a JavaScript Application that has to receive a huge amount of data from other users. It is not important if some of this data gets lost. Is there some way of using JavaScript WebSockets with UDP instead of TCP?

JavaScript WebSockets with UDP?

I am playing around with HTML5 WebSockets. I was wondering, how do I close the connection gracefully? Like, what happens if user refreshes the page, or just closes the browser?

There is a weird behavior when a user just refresh the page without calling `websocket.close()` - when they return after the refresh it will hit the `websocket.onclose` event.

Content Type	Original Author	Original Content on Stackoverflow
Question	Justin	View Question on Stackoverflow
Solution 1 - Html	kanaka	View Answer on Stackoverflow
Solution 2 - Html	user656925	View Answer on Stackoverflow
Solution 3 - Html	Jonas	View Answer on Stackoverflow

Can HTML5 Websockets connect 2 clients (browsers) directly without using a server? (P2P)

Html Problem Overview

Html Solutions

Solution 1 - Html

Solution 2 - Html

Solution 3 - Html

Qt - remove all widgets from layout?

Keep uitableview static when inserting rows at the top

Attributions