PHP Extension

WebSocket Send/Receive Binary Data

See more WebSocket Examples

Demonstrates how to send and receive binary data on a websocket. This example uses Chilkat's websocket test echo server at ws://websockets.chilkat.io/wsChilkatEcho.ashx

Note: The websockets.chilkat.io server imposes the following limitations:
Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.

PHP Extension

<?php

include("chilkat.php");

$success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$ws = new CkWebSocket();

// For brevity, this example does not check for errors when etablishing the WebSocket connection.
// See Establish WebSocket Connection for more complete sample code for making the connection.

$rest = new CkRest();
// Connect to websockets.chilkat.io
// IMPORTANT: websockets.chilkat.io accepts frames of up to 16K in size and echoes them back.
// IMPORTANT: The websockets.chilkat.io server imposes the following limitations: 
// ---------- Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.
$success = $rest->Connect('websockets.chilkat.io',80,false,false);
$ws->UseConnection($rest);
$ws->AddClientHeaders();
$responseBodyIgnored = $rest->fullRequestNoBody('GET','/wsChilkatEcho.ashx');
$success = $ws->ValidateServerHandshake();
if ($success != true) {
    print $ws->lastErrorText() . "\n";
    exit;
}

// This example sends a small JPG file (about 7KB) in a websocket frame.
$jpgData = new CkBinData();
$success = $jpgData->LoadFile('qa_data/jpg/starfish.jpg');

print 'Number of bytes to send = ' . $jpgData->get_NumBytes() . "\n";

// Send a frame containing the JPG image data.
// This will be the first and final frame, and therefore this constitutes the entire message.
$finalFrame = true;
$success = $ws->SendFrameBd($jpgData,$finalFrame);
if ($success != true) {
    print $ws->lastErrorText() . "\n";
    exit;
}

// Read the echoed binary frame(s).
// (We sent the JPG file in a single frame, but we may receive the echo in multiple frames, but it will be one message.)
// Read an incoming frames until we receive the final frame.
$receivedFinalFrame = false;
while ($receivedFinalFrame == false) {

    // The ws object is accumulating the received data internally.  Once we get the final frame, we'll get the 
    // accumulated data which should constitute the entire JPG.
    $success = $ws->ReadFrame();
    if ($success != true) {
        print 'Failed to receive a frame' . "\n";
        print 'ReadFrame fail reason = ' . $ws->get_ReadFrameFailReason() . "\n";
        print $ws->lastErrorText() . "\n";
        exit;
    }

    $receivedFinalFrame = $ws->get_FinalFrame();

    // Show the opcode and final frame bit for the frame just received:
    print 'Frame opcode: ' . $ws->frameOpcode() . "\n";
    print 'Final frame: ' . $receivedFinalFrame . "\n";
}

// Get the accumulated received data.
$jpgReceivedData = new CkBinData();
$ws->GetFrameDataBd($jpgReceivedData);
print 'Received ' . $jpgReceivedData->get_NumBytes() . ' bytes' . "\n";

// Save the received JPG to a file so we can check it..
$jpgReceivedData->WriteFile('qa_output/starfish_ws.jpg');

// Close the websocket connection.
$success = $ws->SendClose(true,1000,'Closing this websocket.');
if ($success != true) {
    print $ws->lastErrorText() . "\n";
    exit;
}

// Read the Close response.
$success = $ws->ReadFrame();
if ($success != true) {
    print 'ReadFrame fail reason = ' . $ws->get_ReadFrameFailReason() . "\n";
    print $ws->lastErrorText() . "\n";
    exit;
}

// Should receive the "Close" opcode.
print 'Received opcode: ' . $ws->frameOpcode() . "\n";
// Should be the same status code we sent (1000)
print 'Received close status code: ' . $ws->get_CloseStatusCode() . "\n";
// The server may echo the close reason.  If not, this will be empty.
print 'Echoed close reason: ' . $ws->closeReason() . "\n";

print 'Success.' . "\n";

?>