#int pq\Connection::on(string $event, callable $callback)

Listen for an event.

Params:#

• string $event#
  Any pq\Connection::EVENT_*.
• callable $callback# as function(pq\Connection $c#[, pq\Result $r#)
  The callback to invoke on event.

Returns:#

• int, number of previously attached event listeners.

Throws:#

• pq\Exception\InvalidArgumentException
• pq\Exception\BadMethodCallException

Example:#

<?php

$connection = new pq\Connection;
$connection->on(pq\Connection::EVENT_RESULT, function($c, $r) {
    printf("Got result with %d rows\n", $r->numRows);
});
$connection->exec("SELECT * FROM generate_series(1,3)");

?>

Yields:

Got result with 3 rows