"Array value found, but an array is required"

[adjenks]

I'm receiving this error message:

"Array value found, but an array is required"

I don't quite understand this error. It's saying that a property is an array, but it needs an array. It seems to me like it has what it wants. This error is not intuitive. Can someone explain to me what the library wants?

[adjenks]

I think I understand what's going on. It's because it is receiving an associative PHP array but it wants an indexed array. It makes it confusing because they are the same 'type' in PHP. You actually have to go through the effort to check if you want to know if something is associative vs indexed in PHP.
See: https://stackoverflow.com/questions/173400/how-to-check-if-php-array-is-associative-or-sequential
So perhaps this library should say:

" Array (with non-integer keys) value found, but an array is required."

Or something of the sort.

[shmax]

Can you please provide a (minimal) schema sample that produces this error?

[adjenks]

Schema (test.json):

{
	"$schema": "http://json-schema.org/draft-04/schema#",
	"type": "array",
	"items": {
		"type": "object",
		"patternProperties": {
			".*": {
				"type": "boolean"
			}
		}
	}
}

Data:
{"test":true}

Code:

	$validator->validate(
		json_decode('{"test":true}',1) // Without the "1" it's a bit more clear and says Object
		,(object)['$ref' => 'file://' . realpath('./schemas/test.json')]
		,Constraint::CHECK_MODE_COERCE_TYPES | Constraint::CHECK_MODE_TYPE_CAST // coerce types for the browser.
	);

Output:
{"errors":[{"detail":"Array value found, but an array is required","property":""}]}

[erayd]

@adjenks Thanks for that - definitely looks like something we ought to improve on.

Out of curiosity, why are you forcing json_decode to use associative arrays instead of objects? It's not the default, and it's an unusual thing to do.

[adjenks]

I just forced json_decode to use an array to demonstrate the problem when you are already working with an array.

[antodippo]

Hi @adjenks, I tried to make this test fail:

public function testValidateAssociativeArray()
    {
        $value = json_decode('{"test":true}', 1);

        $schema = (object) '
        {
            "$schema": "http://json-schema.org/draft-04/schema#",
            "type": "array",
            "items": {
                "type": "object",
                "patternProperties": {
                    ".*": {
                        "type": "boolean"
                    }
                }
            }
        }';

        $validator = new Validator();
        $validator->validate($value, $schema, Constraint::CHECK_MODE_COERCE_TYPES | Constraint::CHECK_MODE_TYPE_CAST);
    }

but it doesn't. On which PHP version are you? I'm on PHP 7.2.

[erayd]

@antodippo You can't cast a string to an object the way you are attempting to do - you just end up with an StdClass object containing a single string property, which obviously is not a sane schema.

Use json_decode(), not (object) casting.

[erayd]

To clarify - the object that results from using (object) on a string is essentially an empty schema, against which any input is considered valid.

[adjenks]

@antodippo
I was using whatever the newest PHP version was when I made the post.
erayd is correct, you can't turn a string into an object. PHP tries to but it makes no sense. See this example:

php > $a = (object)'{"testing":123}';
php > var_export($a);
stdClass::__set_state(array(
   'scalar' => '{"testing":123}',
))
php > echo $a;
PHP Recoverable fatal error:  Object of class stdClass could not be converted to string in php shell code on line 1
php > echo $a->testing;
PHP Notice:  Undefined property: stdClass::$testing in php shell code on line 1

So it's not a string anymore, and it's also not a a decoded json-object. So although casting a string to an object does not initially throw an error, I'm not sure what it's useful for.

[FabienSalles]

Hi,

I have the same problem :

hydra:member[0]: Array value found, but an object is required

My json is :

{
   "@id":"\/product_variants",
   "@type":"hydra:Collection",
   "hydra:member":[
      {
         "@id":"\/product_variants\/my_product",
         "@type":"ProductVariant",
         "code":"my_product",
         "position":0,
         "createdAt":"2019-08-05T16:09:13+00:00",
         "updatedAt":null,
         "optionsValues":[
            {
               "@id":"\/product_option_values\/1",
               "code":"age_class_children",
               "optionCode":"age_class",
               "position":0
            },
            {
               "@id":"\/product_option_values\/3",
               "code":"class_ordinary",
               "optionCode":"class",
               "position":1
            },
            {
               "@id":"\/product_option_values\/5",
               "code":"duration_seven",
               "optionCode":"duration",
               "position":2
            }
         ]
      }
   ]
}

And my simplified shcema in order to get the error :

{
  "type": "object",
    "required": [
    "@id",
    "@type",
    "hydra:member"
  ],
 "properties": {
 "hydra:member": {
   "type": "array",
   "items": {
     "type": "object",
     "required": [
       "@id",
       "@type",
       "code",
       "position",
       "createdAt",
        "updatedAt",
        "optionsValues"
       ]
     }
   }
 }
 }

How can we validate a collection of object ?

EDIT : sorry it's not really the same issue. If I indicate that my type is an array for my hydra:member items, the schema is valid. But for me this should be an object.

[DannyvdSluijs]

I've been trying to read up on this issue and try to understand. My summary up until now is

• The original report was made to highlight that under certain circumstances an error message is returned which makes no sense: "Array value found, but an array is required"
• The root cause of the weird error message is due to the forcing of an associative array (a concept unknown in JSON)
• "Array value found, but an array is required" #523 (comment) is a so called Red herring and seemingly has nothing to do with the original report.
• "Array value found, but an array is required" #523 (comment) seems to be another issue by itself. although in v6.0.0 the JSON is valid as per provided schema. @FabienSalles if you think this is still an issue please open a new issue.

This is caused because the json_decode is done using $associative = true. This creates an associative array type which is possible in PHP but isn't possible in JSON. Which leads me to believe the core of the issue is the forcing of an associative array. As already mentioned by @erayd in #523 (comment)

@adjenks in #523 (comment) you mention you used $associative = true to enforce the array. It is actually the only way you could trigger the issue as there is no valid JSON string to have a associative array in JSON. You can see in below snippet that an associative array is actually an object in JSON

$input = ['test' => true, 'test2' => 3];
echo json_encode($input);

// {"test":true,"test2":3}

I'll close the issue for now as the problem is caused by using the $associative = true when calling json_decode which should not be done as you are actually manipulating the JSON.

If any of the above is unclear or incorrect, feel free to reopen the issue with additional information

[adjenks]

@DannyvdSluijs
Ah, my point was that the data I was using came from another library and it was provided already in associative array format. I'm not setting $associative=true in my real code, I'm not even using json_decode, it was just used as an example to display the confusing error. Sometimes you need to work with various forms of data.

The point was that the error message was very obscure and confusing and I was just hoping that at least the error message could be more clear by saying "Associative Array value found, but an array is required" or interpret it as an object and say "Object found, but an array is required".

It doesn't really matter to me now since it's been so long and I've dealt with it somehow, but I still think my request was valid.

Perhaps minimally, the docs could give a disclaimer that associative arrays come with issues and are not recommended as values.