PHP ActiveX Requires Chilkat v11.0.0+

Firebase Receive Server-Sent Events (text/event-stream)

See more Firebase Examples

Demonstrates how to start receiving server-sent events and update your JSON database with each event. PHP ActiveX

<?php

$success = 0;

//  Demonstrates how to begin receiving server-sent events, and to update
//  your JSON database for each event.

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

//  This example assumes a JWT authentication token, if required, has been previously obtained.
//  See Get Firebase Access Token from JSON Service Account Private Key for sample code.

//  Load the previously obtained Firebase access token into a string.
$fac = new COM("Chilkat.FileAccess");
$accessToken = $fac->readEntireTextFile('qa_data/tokens/firebaseToken.txt','utf-8');
if ($fac->LastMethodSuccess == 0) {
    print $fac->LastErrorText . "\n";
    exit;
}

$rest = new COM("Chilkat.Rest");

//  Make the initial connection (without sending a request yet).
//  Once connected, any number of requests may be sent.  It is not necessary to explicitly
//  call Connect before each request.  
$success = $rest->Connect('chilkat.firebaseio.com',443,1,1);
if ($success == 0) {
    print $rest->LastErrorText . "\n";
    exit;
}

$authGoogle = new COM("Chilkat.AuthGoogle");
$authGoogle->AccessToken = $accessToken;
$rest->SetAuthGoogle($authGoogle);

$rest->AddHeader('Accept','text/event-stream');
$rest->AddHeader('Cache-Control','no-cache');

$responseBody = $rest->fullRequestNoBody('GET','/.json');

//  A 307 redirect response is expected.
if ($rest->ResponseStatusCode != 307) {
    print 'Unexpected response code: ' . $rest->ResponseStatusCode . "\n";
    print $responseBody . "\n";
    print 'Failed.' . "\n";
    exit;
}

//  Get the redirect URL
$urlStr = $rest->LastRedirectUrl;
$url = new COM("Chilkat.Url");
$url->ParseUrl($urlStr);

print 'redirect URL domain: ' . $url->Host . "\n";
print 'redirect URL path: ' . $url->Path . "\n";
print 'redirect URL query params: ' . $url->Query . "\n";
print 'redirect URL path with query params: ' . $url->PathWithQueryParams . "\n";

//  Our text/event-stream will be obtained from the redirect URL...
$rest2 = new COM("Chilkat.Rest");

$success = $rest2->Connect($url->Host,443,1,1);
if ($success != 1) {
    print $rest2->LastErrorText . "\n";
    exit;
}

$rest2->AddHeader('Accept','text/event-stream');
$rest2->AddHeader('Cache-Control','no-cache');

//  Add the redirect query params to the request
$rest2->AddQueryParams($url->Query);

//  In our case, we don't actually need the auth query param,
//  so remove it.
$rest2->RemoveQueryParam('auth');

//  Send the request.  (We are only sending the request here.
//  We are not yet getting the response because the response
//  will be a text/event-stream.)
$success = $rest2->SendReqNoBody('GET',$url->Path);
if ($success != 1) {
    print $rest2->LastErrorText . "\n";
    exit;
}

//  Read the response header.  
//  We want to first get the response header to see if it's a successful
//  response status code.  If not, then the response will not be a text/event-stream
//  and we should read the response body normally.
$responseStatusCode = $rest2->ReadResponseHeader();
if ($responseStatusCode < 0) {
    print $rest2->LastErrorText . "\n";
    exit;
}

//  If successful, a 200 response code is expected.
//  If the reponse code is not 200, then read the response body and fail..
if ($responseStatusCode != 200) {
    print 'Response Code: ' . $responseStatusCode . "\n";
    print 'Response Status Text: ' . $rest2->ResponseStatusText . "\n";
    print 'Response Header: ' . $rest2->ResponseHeader . "\n";
    $responseBody = $rest2->readRespBodyString();
    if ($rest2->LastMethodSuccess == 1) {
        print 'Error Response Body: ' . $responseBody . "\n";
    }

    print 'Failed.' . "\n";
    exit;
}

//  For this example, our JSON database will be empty at the beginning.
//  The incoming events (put and patch) will be applied to this database.
$jsonDb = new COM("Chilkat.JsonObject");

//  Make sure to set the JSON path delimiter to "/".  The default is "." and this
//  is not compatible with Firebase paths.
$jsonDb->DelimiterChar = '/';

//  At this point, we've received the response header.  Now it's time to begin
//  receiving the event stream.  We'll start a background thread to read the 
//  stream.  (Our main application (foreground) thread can cancel it at any time.)  
//  While receiving in the background thread, our foreground thread can read the stream
//  as it desires..
$eventStream = new COM("Chilkat.Stream");

//  This sse object will be used as a helper to parse the server-sent event stream.
$sse = new COM("Chilkat.ServerSentEvent");

// task is a Chilkat.Task
$task = $rest2->ReadRespBodyStreamAsync($eventStream,1);
$task->Run();

//  For this example, we'll just read a few events, and then cancel the
//  async task.
$count = 0;
while (($count < 3) and ($task->Finished == 0)) {

    //  Get the next event, which is a series of text lines ending with
    //  a blank line. 
    //  Note: This method blocks the calling thread until a message arrives.
    //  a program might instead periodically check the availability of
    //  data via the stream's DataAvailable property, and then do the read.

    //  An alternative to writing a while loop to read the event stream
    //  would be to setup some sort of timer event in your program (using whatever timer functionality
    //  is provided in a programming language/environment), to periodically check the eventStream's
    //  DataAvailable property and consume the incoming event.
    $eventStr = $eventStream->readUntilMatch('\r\n\r\n');
    if ($eventStream->LastMethodSuccess != 1) {
        print $eventStream->LastErrorText . "\n";
        //  Force the loop to exit by setting the count to a high number.
        $count = 99999;
    }
    else {
        print 'Event: [' . $eventStr . ']' . "\n";

        //  We have an event. Let's update our local copy of the JSON database.
        $success = $sse->LoadEvent($eventStr);
        if ($success != 1) {
            print 'Failed to load sse event: ' . $eventStr . "\n";
        }
        else {
            //  Now we can easily access the event name and data, and apply it to our JSON database:
            $success = $jsonDb->FirebaseApplyEvent($sse->EventName,$sse->Data);
            if ($success != 1) {
                print 'Failed to apply event: ' . $sse->EventName . ': ' . $sse->Data . "\n";
            }
            else {
                print 'Successfully applied event: ' . $sse->EventName . ': ' . $sse->Data . "\n";
            }

        }

    }

    $count = $count + 1;
}

//  Make sure the background task is cancelled if still running.
$task->Cancel();

//  Examine the JSON database after applying events..
$jsonDb->EmitCompact = 0;
print '----' . "\n";
print $jsonDb->emit() . "\n";

?>