AWS PHP getIterator doesn't work - returns empty results

Question

Should be simple code. I have AWS SDK PHP v3 and I created code like this:

require 'aws/aws-autoloader.php';

use Aws\S3\S3Client;

$s3Client = new S3Client([
    'version' => 'latest',
    'region' => 'eu-west-1',
    'credentials' => [
        'key' => "accesskey",
        'secret' => "secretkey",
    ],
]);

print_r($result = $s3Client->listBuckets())

Now I see my buckets list, but when I tried get ObjectList getIterator like this:

$objects = $s3Client->getIterator('ListObjects', array(
    'Bucket' => "bucket")
);

var_dump($objects);

I see: object(Generator)#95 (0) { }

I am struggling with this second day and I can't find solution? Anyone knows what I do wrong?

Answer 1

I ran in to a similar issue in which is seemed like the returned contents were empty when using print_r on the results of getIterator:

print_r($result);

Generator Object
(
)

And with var_dump:

var_dump($result);

object(Generator)#62 (0) {
}

I knew there were results for the bucket, so I was confused why it was always showing 0 results. This literally needs to be iterated by using foreach, and then the results are revealed:

foreach ($result as $object) {
 echo $object['Key']."\n";
}

There are the results!

Also, you can use listObjectsV2 instead of listObjects for the more modern implementation, and you can use the PHP command iterator_to_array to convert the results in to an array.

Here is a functional portion of my S3 class:

<?php
require_once('aws.phar');

class S3 {

 private $region = 'us-east-1';
 private $s3;

 public function create() {
  try {
   $this->s3 = Aws\S3\S3Client::factory(array(
    'credentials' => array(
     'key' => AWS_ACCESS_KEY_ID,
     'secret' => AWS_SECRET_ACCESS_KEY),
    'region' => $this->region,
    'version' => 'latest'
   ));

   return ($this->s3 ? true : false);
  }
  catch (Aws\Exception\AwsException $e) {throw new Exception($e->getMessage());}
  catch (Aws\S3\Exception\S3Exception $e) {throw new Exception($e->getAwsErrorType().' '.$e->getAwsErrorCode());}
  catch (Exception $e) {throw new Exception($e->getMessage());}

  return false;
 }

 public function listObjects($bucket,$prefix = '',$start_after = '',$max_keys = '') {
  if (!$this->checkActive()) return false;

  $args = array('Bucket' => $bucket,'EncodingType' => 'url');

  if ($max_keys > 0) $args['MaxKeys'] = intval($max_keys);
  if ($prefix) $args['Prefix'] = $prefix;
  if ($start_after) $args['StartAfter'] = $start_after;

  try {
   $response = $this->s3->ListObjectsV2($args);

   if (!$response) return false;

   $data = $response->toArray();
   return (isset($data['Contents']) ? $data['Contents'] : array());
  }
  catch (Aws\Exception\AwsException $e) {throw new Exception ($e->getMessage());}
  catch (Aws\S3\Exception\S3Exception $e) {throw new Exeception ($e->getAwsRequestId().' : '.$e->getAwsErrorType().' : '.$e->getAwsErrorCode());}
  catch (Exception $e) {throw new Exception ($e->getMessage());}
 }

 public function listAllObjects($bucket,$prefix = '') {
  if (!$this->checkActive()) return false;

  $args = array('Bucket' => $bucket,'EncodingType' => 'url');
  if ($prefix) $args['Prefix'] = $prefix;

  try {
   $response = $this->s3->getIterator('ListObjectsV2',$args,$args);
   if (!$response) return false;
   return iterator_to_array($response);
  }
  catch (Aws\Exception\AwsException $e) {throw new Exception ($e->getMessage());}
  catch (Aws\S3\Exception\S3Exception $e) {throw new Exeception ($e->getAwsRequestId().' : '.$e->getAwsErrorType().' : '.$e->getAwsErrorCode());}
  catch (Exception $e) {throw new Exception ($e->getMessage());}
 }

 private function checkActive() {
  if ($this->s3) return true;
  return $this->create();
 }

}

try {
 $s3 = new S3();
 $list = $s3->listObjects($bucket,$key_starts_with,$full_key_to_start_after,$number_to_return);
 print_r($list);

 $list = $s3->listAllObjects($bucket,$key_starts_with);
 print_r($list);
}
catch (Exception $e) {echo 'Error: '.$e->getMessage();}