README.md

Simple "Hello World!" example using PHP's cURL

On this example you are going to learn how to create a simple PHP script using cURL, to send and retrieve data from the AIoD API and to even do some basic handling of the responses. The full version of the code can be found on api-simple-example.php, which can be run directly via any terminal using the php api-simple-example.php command.

Before starting, please make sure that the AIoDP API has been successfully installed on your local machine and that you can access it via your web browser at localhost:8000. For more information read the Prerequisites and the Getting Started guide.

1. Create a new PHP Script

To start, open a text/code editor and create a new file, e.g. 'simple-example.php'.

2. Populate an array that represents the news item's data

Set up a basic PHP script that initialises and populates an array that represents the news item's data, as defined by the schema which can be found at the AIoD API documentation. To keep things simple, only the required (and some optional) metadata could be filled:

<?php

$data = [
    # Required fields:
    'title' => 'Hello World Simple Edition!',
    'dateModified' => '2023-05-30T14:22:00+00:00',
    'headline' => 'Hello World! The AIoD API salutes you!',
    'section' => 'Hello World News',
    'body' => 'This is the main body of the simple news item.',
    'wordCount' => 9,
    # Some optional fields:
    'source' => 'AIoD API Examples: PHP',
    'businessCategories' => ['Cloud, Edge and Infrastructure'],
    'keywords' => ['API', 'Education'],
];

TIP: * $data['dateModified'] could be set to gmdate(DATE_ATOM) for the current date and time in ISO 8601 format, while $data['wordCount'] could be easily calculated at a later point with str_word_count($data['body']).

3. Convert the data to JSON

The array of data can't be posted directly the API. It has to be converted to JSON format using json_encode():

$json_data = json_encode($data);

4. Define the endpoint and set up the cURL session

To insert data to the API an endpoint has to be used which allows the creation of a news item. This can also be easily found at the AIoD API documentation.

$url = 'http://localhost:8000/news/v0';

Then, the script should initialize a cURL session using curl_init() and sets various options such as making a POST request, setting the $json_data as the request body, and specifying the content type and length headers.

$curl = curl_init($url);

$options = [
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => $json_data,
    CURLOPT_HTTPHEADER => [
        'Content-Type: application/json',
        'Content-Length: ' . strlen($json_data)
    ],
    CURLOPT_RETURNTRANSFER => true,
];

curl_setopt_array($curl, $options);

5. Send the data and get the response

The cURL session sends the request to the API and the response is stored in the $response variable.

$response = curl_exec($curl);

And that's basically is all it takes to insert a news item to the AIoD API!

---

Optional handling of the response

At this point the HTTP status code of the response could be checked using curl_getinfo() and if it's not 200 (OK) an error message could be displayed or an exception could be thrown.

$http_status = curl_getinfo($curl, CURLINFO_HTTP_CODE);
if ($http_status !== 200) {
    // Some basic error handling could go here...
    echo "HTTP Status Code: " . $http_status . PHP_EOL;
} else {
    // But hopefully, there were no issues with our code!
    echo "Data inserted successfully!" . PHP_EOL;
}

---

Finally, the cURL session is closed using curl_close().

curl_close($curl);

6. The 'Hello World!' greeting

... But, we are still missing a 'Hello World!' greeting, so let's get it! The $response from the API can be decoded from JSON to an associative array using json_decode($response, true), and from that, we can extract the description and display it on screen using a simple good-old echo:

$response_data = json_decode($response, true);
$headline = $response_data['headline'];
echo $headline;

[ Return to the Index of this repository ]