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MongoDB\Client::addSubscriber()

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  • Definition
  • Parameters
  • Errors/Exceptions
  • Behavior
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New in version 1.18.

MongoDB\Client::addSubscriber()

Registers a monitoring event subscriber with this Client. The subscriber will be notified of all events for this Client.

function addSubscriber(MongoDB\Driver\Monitoring\Subscriber $subscriber): void
$subscriber : MongoDB\Driver\Monitoring\Subscriber
A monitoring event subscriber to register with this Client.

MongoDB\Exception\InvalidArgumentException for errors related to the parsing of parameters or options.

MongoDB\Driver\Exception\InvalidArgumentException if subscriber is a MongoDB\Driver\Monitoring\LogSubscriber, since loggers can only be registered globally with MongoDB\Driver\Monitoring\addSubscriber.

If $subscriber is already registered with this Client, this function is a no-op. If $subscriber is also registered globally, it will still only be notified once of each event for this Client.

Create a MongoDB\Driver\Monitoring\CommandSubscriber that logs all events:

<?php
use MongoDB\Driver\Monitoring\CommandSubscriber;
use MongoDB\Driver\Monitoring\CommandStartedEvent;
use MongoDB\Driver\Monitoring\CommandSucceededEvent;
use MongoDB\Driver\Monitoring\CommandFailedEvent;
class LogCommandSubscriber implements CommandSubscriber
{
private $stream;
public function __construct($stream)
{
$this->stream = $stream;
}
public function commandStarted(CommandStartedEvent $event): void
{
fwrite($this->stream, sprintf(
'Started command #%d "%s": %s%s',
$event->getRequestId(),
$event->getCommandName(),
Document::fromPHP($event->getCommand())->toCanonicalExtendedJSON(),
PHP_EOL,
));
}
public function commandSucceeded(CommandSucceededEvent $event): void
{
fwrite($this->stream, sprintf(
'Succeeded command #%d "%s" in %d microseconds: %s%s',
$event->getRequestId(),
$event->getCommandName(),
$event->getDurationMicros(),
json_encode($event->getReply()),
PHP_EOL,
));
}
public function commandFailed(CommandFailedEvent $event): void
{
fwrite($this->stream, sprintf(
'Failed command #%d "%s" in %d microseconds: %s%s',
$event->getRequestId(),
$event->getCommandName(),
$event->getDurationMicros(),
$event->getError()->getMessage(),
PHP_EOL,
));
}
}

The subscriber can then be registered with a Client:

<?php
$client = new MongoDB\Client();
$subscriber = new LogCommandSubscriber(STDERR);
$client->addSubscriber($subscriber);
$client->test->users->insertOne(['username' => 'alice']);

The above code will write the following to stderr output:

Started command #1 "insert": { "insert" : "users", "ordered" : true, "$db" : "test", "lsid" : { "id" : { "$binary" : { "base64" : "dKTBhZD7Qvi0vUhvR58mCA==", "subType" : "04" } } }, "documents" : [ { "username" : "alice", "_id" : { "$oid" : "655d1fca12e81018340a4fc2" } } ] }
Succeeded command #1 "insert" in 876 microseconds: {"n":1,"ok":1}
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