passing Curl parameter as a parameter

Question

I have a curl function that requests data on Asteroids and get backs results. Currently I am just hard coding in the date parameters for the result, I would like the user to be able to enter their selected dates and get the result how could I add this, I am new to using Curl and keep hitting a wall, the code so far is below,

<?php
session_start();
// Method: POST, PUT, GET etc
// Data: array("param" => "value") ==> index.php?param=value

function CallAPI($method, $url, $data = false)
{
    $curl = curl_init();

    switch ($method) {
        case "POST":
            curl_setopt($curl, CURLOPT_POST, 1);

            if ($data)
                curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
            break;
        case "PUT":
            curl_setopt($curl, CURLOPT_PUT, 1);
            break;
        default:
            if ($data)
                $url = sprintf("%s?%s", $url, http_build_query($data));
    }
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
    $result = curl_exec($curl);
    if ($result === FALSE) {
        die(curl_error($curl));
    }
    curl_close($curl);
    return $result;
}
$params = array(
    'start_date' => '01/03/2016',
    'end_date' => '02/03/2016',
    'api_key' => 'demo key'
);
$data   = json_decode(callAPI('GET', 'https://api.nasa.gov/neo/rest/v1/feed', $params));

//var_dump($data);

echo "<h1>Near-Earth Object (NEO) Report between " . $params['start_date'] . " and " . $params['end_date'] . "</h1>";

foreach ($data->near_earth_objects as $date => $count) {
    echo "<p>" . sizeof($count) . " objects detected on $date</p>";

    echo "<ol>";
    foreach ($data->near_earth_objects->$date as $near_earth_object) {
        echo "<li>" . $near_earth_object->name . " <a href='" . $near_earth_object->nasa_jpl_url . "'>" . $near_earth_object->nasa_jpl_url . "</a><br>";
        echo "Estimated Diameter: " . $near_earth_object->estimated_diameter->meters->estimated_diameter_min . "-" . $near_earth_object->estimated_diameter->meters->estimated_diameter_max . " metres<br>";

        echo "<ul>";
        foreach ($near_earth_object->close_approach_data as $close_approach) {
            echo "<li>Close approach on " . $close_approach->close_approach_date . " velocity " . $close_approach->relative_velocity->kilometers_per_hour . " km/h " . "missing " . $close_approach->orbiting_body . " by " . $close_approach->miss_distance->kilometers . " km</li> ";
        }
        echo "</ul></li>";
    }
    echo "</ol>";
}
?>

Answer 1

You were close. I modified your code slightly. The date format you had was also incorrect. You were providing the format mm/dd/yyyy when the API calls for a format of yyyy-mm-dd (notice the year goes in front and you need hyphens instead of slashes).

I used GET values for the start and end date (note the API only allows 7 days between the start and end dates). So you can change the date by adding ?start=2015-05-01&end=2015-05-05 to the end of the URL you use to access this code (it could also be implemented as a GET-method form):

<?php
session_start();
// Method: POST, PUT, GET etc
// Data: array("param" => "value") ==> index.php?param=value

function CallAPI($method, $url, $data = false)
{
    $curl = curl_init();

    switch ($method) {
        case "POST":
            curl_setopt($curl, CURLOPT_POST, 1);

            if ($data)
                curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
            break;
        case "PUT":
            curl_setopt($curl, CURLOPT_PUT, 1);
            break;
        default:
            if ($data)
                $url = sprintf("%s?%s", $url, http_build_query($data));
    }
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
    $result = curl_exec($curl);
    if ($result === FALSE) {
        die(curl_error($curl));
    }
    curl_close($curl);
    return $result;
}

$startDate = date('Y-m-d', strtotime(isset($_GET['start']) ? $_GET['start'] : date('Y-m-d')));
$endDate = date('Y-m-d', strtotime(isset($_GET['end']) ? $_GET['end'] : date('Y-m-d')));

if( !$startDate ) {
    $startDate = date('Y-m-d');
}

if( !$endDate ) {
    $endDate = date('Y-m-d');
}

$params = array(
    'start_date' => $startDate,
    'end_date' => $endDate,
    'api_key' => 'NNKOjkoul8n1CH18TWA9gwngW1s1SmjESPjNoUFo'
);

$data = json_decode(callAPI('GET', 'https://api.nasa.gov/neo/rest/v1/feed', $params));

echo "<h1>Near-Earth Object (NEO) Report between " . $params['start_date'] . " and " . $params['end_date'] . "</h1>";

foreach ($data->near_earth_objects as $date => $count) {
    echo "<p>" . sizeof($count) . " objects detected on $date</p>";

    echo "<ol>";
    foreach ($data->near_earth_objects->$date as $near_earth_object) {
        echo "<li>" . $near_earth_object->name . " <a href='" . $near_earth_object->nasa_jpl_url . "'>" . $near_earth_object->nasa_jpl_url . "</a><br>";
        echo "Estimated Diameter: " . $near_earth_object->estimated_diameter->meters->estimated_diameter_min . "-" . $near_earth_object->estimated_diameter->meters->estimated_diameter_max . " metres<br>";

        echo "<ul>";
        foreach ($near_earth_object->close_approach_data as $close_approach) {
            echo "<li>Close approach on " . $close_approach->close_approach_date . " velocity " . $close_approach->relative_velocity->kilometers_per_hour . " km/h " . "missing " . $close_approach->orbiting_body . " by " . $close_approach->miss_distance->kilometers . " km</li> ";
        }
        echo "</ul></li>";
    }
    echo "</ol>";
}

The dates can be entered in any format that strtotime understands. In the event of an invalid date it will default to todays date. If the API throws an error (like when the date range is larger than 7 days), it will just throw an error. You may want to add some error detection.