Symfony, how to render and save use form - arrays

Question

Imagine I have an Article entity, and in this entity have a report attribute which is a json_array type.
Json_array's data like {"key1":"value1","ke2":"value2",...}.
Now I don't know how to use symfony form to render and save these json_array like other normal attribute(e.g.,title).
I searched many articles but I haven't find a clear way to realize it.
class Article
{
/**
* #var int
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="title", type="string", length=255)
*/
private $title;
/**
* #var array
*
* #ORM\Column(name="report", type="json_array")
*/
private $report;
}

Answer 1

Here is my take on it. It sounds like you need a custom form type in a collection and a transformer. The idea is that you create a custom form type to house your key/value pairs, let's call it KeyValueType. Next you want to add this type to your ArticleType using a CollectionType as a wrapper. In order to turn your json to a useable data structure for the form and vice versa a transformer is used.
The KeyValueType class:
class KeyValueType extends AbstractType
{
public function buildForm($builder, $options)
{
$builder
->add('key')
->add('value');
}
}
The ArticleType class:
class ArticleType extends AbstractType
{
public function buildForm($builder, $options)
{
$builder
->add('report', CollectionType::class, [
'entry_type' => KeyValueType::class,
'allow_add' => true,
'allow_delete' => true,
]);
$builder->get('report')
->addModelTransformer(new CallbackTransformer(
function ($reportJson) {
// $reportJson has the structure {"key1":"value1","ke2":"value2",...}
if ($reportJson == null) {
return null;
}
$data = [];
foreach (json_decode($reportJson, true) as $key => $value) {
$data[] = ['key' => $key, 'value' => $value];
}
return $data;
},
function ($reportArray) {
// $reportArray has the structure [ [ 'key' => 'key1', 'value' => 'value1'], [ 'key' => 'key2', 'value' => 'value2'] ]
if ($reportArray == null) {
return null;
}
$data = [];
foreach ($reportArray as $report) {
$data[$report['key']] = $report['value'];
}
return json_encode($data);
}
));
}
}