Firebase PHP Adding Map to Array

Question

I'm trying to use the Firebase PHP API to update/append a document field's array with a map

I have the following code in Python that works fine

ref = db.collection(u'jobs').document(jobId)
                ref.update({
                        u'messages': firestore.ArrayUnion([{
                                u'category': u'0',
                                u'message': u'TEST',
                                u'sender': u'TEAM',
                                }])
                        })

Though when I try to replicate it in PHP, it doesn't work. I tried a lot of different ways to view the errors, but all I get is 500 INTERNAL SERVER ERROR.

require 'vendor/autoload.php';
use Google\Cloud\Firestore\FirestoreClient;
use Google\Cloud\Firestore\FieldValue;
$firestore = new FirestoreClient([
    'projectId' => 'XXX-XX',
    'credentials' => 'key.json'
]);


$jobId = "XXXX";
$docRef = $firestore->collection('jobs')->document($jobId);
$docRef->update([
        'messages' => FieldValue::arrayUnion([{
            'category' : '0',
            'message' : 'TEST',
            'sender' : 'TEAM',
        }])
]);

I looked up samples of Array Union in PHP, adding data with PHP. I've tried a lots of variations of : or => or arrayUnion([]) or arrayUnion({[]}) to no avail.

Any idea what is causing this?

Answer 1

Looks like there's a few things going wrong here.

First, PHP uses arrays for both maps and "normal" arrays. There is no object literal ({}) in PHP. Array values are specified using the => operator, not :.

Second, DocumentReference::update() accepts a list of values you wish to change, with the path and value. So an update call would look like this:

$docRef->update([
    ['path' => 'foo', 'value' => 'bar']
]);

You can use DocumentReference::set() for the behavior you desire. set() will create a document if it does not exist, where update() will raise an error if the document does not exist. set() will also replace all the existing fields in the document unless you specify merge behavior:

$docRef->set([
    'foo' => 'bar'
], ['merge' => true]);

Therefore, your code can be re-written as either of the following:

$jobId = "XXXX";
$docRef = $firestore->collection('jobs')->document($jobId);
$docRef->set([
    'messages' => FieldValue::arrayUnion([[
        'category' => '0',
        'message' => 'TEST',
        'sender' => 'TEAM',
    ]])
], ['merge' => true]);

$jobId = "XXXX";
$docRef = $firestore->collection('jobs')->document($jobId);
$docRef->update([
    [
        'path' => 'messages', 'value' => FieldValue::arrayUnion([[
            'category' => '0',
            'message' => 'TEST',
            'sender' => 'TEAM',
        ]])
    ]
]);

One final thing to note: arrayUnion will not append duplicate values. So if the value you provide (including all keys and values in the nested map) already exists, it will not be appended to the document.

If you haven't already, turn up error reporting in your development environment to receive information about why your code is failing. PHP will inform you about the parse errors your snippet included, and the Firestore client will give you errors which can often be quite useful.