generators.php

<?php

// Example: Iterate over all resources from a paginated API endpoint
// PHP 5 vs PHP 7

// Both examples iterate over records like this:
foreach (findAll() as $row) {
    // Handle $row
}

// PHP 5

function findAll()
{
    return getAllFromPage(1, []);
}

function getAllFromPage($pageNumber, $rows)
{
    $url = sprintf('?page=%d', $pageNumber);
    $response = $this->restClient->query($url); // body is in $responseBody

    $results = json_decode($responseBody, true);

    foreach ($results['hits'] as $hit) {
        $rows[] = new MakeModel($hit['make'], $hit['model']);
    }

    if ($nextpagehasrecords) {
        $rows = $this->getAllFromPage(++$pageNumber, $rows); // $rows can grow HUGE, it's all in memory
    }
    return $rows;
}

//
// PHP 7
//

function findAll()
{
    yield from getAllFromPage(1);
}

function getAllFromPage($pageNumber)
{
    $url = sprintf('?page=%d', $pageNumber);
    $response = $this->restClient->query($url); // body is in $responseBody

    $results = json_decode($responseBody, true);

    foreach ($results['hits'] as $hit) {
        yield new MakeModel($hit['make'], $hit['model']);
    }

    if ($nextpagehasrecords) {
        yield from $this->getAllFromPage(++$pageNumber); // will yield each row to the caller 1-by-1
    }
}