Google Analytics Data API v1: Execute runReport and retrieve only JSON data

Question

Currently I'm trying to get json data from GA4 using Google Analytics Data API v1. However, the response returned is not pure json data, instead if I just print it using PHP it gives me {}. However, using predefined methods we can get the value. Is there any way to get pure json data?

<?php
putenv('GOOGLE_APPLICATION_CREDENTIALS=xxx.json');

require_once 'vendorautoload.php';

use GoogleAnalyticsDataV1betaBetaAnalyticsDataClient;
use GoogleAnalyticsDataV1betaDateRange;
use GoogleAnalyticsDataV1betaDimension;
use GoogleAnalyticsDataV1betaMetric;
use GoogleCloudBigQueryConnectionRest;

$property_id = 'xxx'; // GA4 property ID

// Using a default constructor instructs the client to use the credentials
// specified in GOOGLE_APPLICATION_CREDENTIALS environment variable.
$client = new BetaAnalyticsDataClient();

// Make an API call.
$response = $client->runReport([
  'property' => 'properties/' . $property_id,
  'dateRanges' => [
    new DateRange([
      'start_date' => '2022-06-30',
      'end_date' => 'today',
    ]),
  ],
  'dimensions' => [
    new Dimension(
      [
        'name' => 'city',
      ]
    ),
  ],
  'metrics' => [
    new Metric(
      [
        'name' => 'activeUsers',
      ]
    )
  ]
]);

print 'Report result: ' . PHP_EOL;

printVisitorsLocationInNumber($response);

function printVisitorsLocationInNumber($resp) {
  foreach ($resp->getRows() as $row) {
    echo
    $row->getDimensionValues()[0]->getValue() . ' ' . $row->getMetricValues()[0]->getValue() . PHP_EOL . '</br>';;
  }
}

Answer 1

echo $response->serializeToJsonString(); // Prints JSON string

$response is an instance of \Google\Analytics\Data\V1beta\RunReportResponse, which extends from \Google\Protobuf\Internal\Message. So you can use the same serializeToJsonString() method.