Element-API: Access the first url of an asset array

Question

I have an asset field in my current project with the handle postImage, containing multiple image files. In my element-api endpoint, I wish to access the url of the first file only.

I tried the following code:

$imgs = $entry->postImage;
$imgUrl = $imgs[0]->getUrl();

The resulting console error message says:

500 (Call to a member function getUrl() on string)

Looping through the array works fine, but I don't want all image urls, just the first one.

It's probably very easy, but that ties a knot my brain. I don't understand where the array is being converted to a string, can anyone hint me to the solution?

Thanks a lot!

Answer 1

you could use array_values() to fetch the first image:

...
      'transformer' => function (Entry $entry) {
        foreach ($entry->images as $image) {
          $images[] = $image->url;
        }
        return [
          'images' =>  array_values($images)[0],
        ];
      },
...

or use reset()

...
      'transformer' => function (Entry $entry) {
        foreach ($entry->images as $image) {
          $images[] = $image->url;
        }
        return [
          'images' =>  reset($images),
        ];
      },
...

Answer 2

You can do something like this:

'transformer' => function(craft\elements\Entry $entry) {
    $image = $entry->photos->one();

    return [
        'image' => $image ? $image->url : null,
    ];
},

More info here.

Answer 3

I was wondering this myself, and I figured there had to be an easier built-in Craft solution rather than using pure PHP like HendrikEng suggested, and it turns out there is! Just use $entry->assetsFieldHandle->one()->url:

use craft\elements\Entry;

return [
    'endpoints' => [
        'entries.json' => function() {
            return [
                'elementType' => Entry::class,
                'elementsPerPage' => 10,
                'criteria' => [
                    'section' => 'blog'
                ],
                'transformer' => function(Entry $entry) {
                    return [
                        'id' => $entry->id,
                        'title' => $entry->title,
                        'url' => $entry->url,
                        'mainImg' => $entry->mainImg->one()->url
                    ];
                }
            ];
        }
    ]
];