Uploading Files

Files can be uploaded to the system for a variety of purposes;

• Getting attached to documents

• Uploading an ID photo to someones profile

• Getting attached to a persons skill/qualification

To do this, files are;

1. Uploaded to Amazon S3 to a temporary file storage location

2. Then moved (internally) to their proper storage location (depending on what they’ll be used for - eg. as a document / ID photo / etc). This step is done by including the file information as part of the request to update data - eg. if you would like a photo to be set as someones ID photo, the temporary-location information is passed in with the request to update someones information.

To upload a file to this temporary storage location;

1. An API request must first be made to obtain a signed-url

2. A signed URL with some form fields are returned from your request for a signed-url

3. Using the signed URL & form-fields, submit your request with the file-data to Amazon S3

A PHP sample of the code required to submit the file data is included below;

composer.json

{
    "require": {
        "guzzlehttp/guzzle": "~6.0"
    }
}

test.php

<?php

require 'vendor/autoload.php';

use GuzzleHttp\Client;

$client = new Client();

$arr = json_decode('... JSON DATA GOES HERE ...', true);

$postVals = [];
foreach ($arr['formData'] as $key => $val) {
    $postVals[] = [
        'name' => $key,
        'contents' => $val,
    ];
}

$localFilePath = './myfile.png';
$fileMimeType = 'image/png';
$remoteFileName = 'myfile.png';

$multipart = array_merge(
    $postVals,
    [
        [
            'name' => 'Content-Type',
            'contents' => $fileMimeType,
        ],
        [
            'name' => 'file',
            'contents' => fopen($localFilePath, 'r'),
            'filename' => $remoteFileName,
            'headers' => [
                'Content-Type' => $fileMimeType,
            ],
        ],
    ]
);

print_r($multipart);

$response = $client->request(
    'POST',
    $arr['url'],
    [
        'multipart' => $multipart,
    ]
);

print_r($response);

Running php test.php will output the metadata which is being sent, as well as information about the response received.

A key will be included in the multipart array (the first shown), generally starting with ‘temporary-uploads/…’. This will represent the ‘path’ when referring to this uploaded file in subsequent requests - eg. to attach the file to a new document, or use it as an ID photo for a person in the system.

AWS provides more information on this concept here; https://docs.aws.amazon.com/AmazonS3/latest/dev/PresignedUrlUploadObject.html