Upload field multi selection auto detection breaking with inline editor

[mfendeksilverstripe]

CMS version: 4.13
Elemental version 4.9.0

UploadField::getIsMultiUpload() has auto-detection capability - it can guess if multiple fields are allowed or not based on the related DB record.

To reproduce this, create a has_one relation to File on a new elemental block, and add an UploadField without explicitly setting isMultiUpload. It will accept multiple files.

More specific details

public function getIsMultiUpload()
{
    if (isset($this->multiUpload)) {
        return $this->multiUpload;
    }
    // Guess from record
    $record = $this->getRecord();
    $name = $this->getName(); // <------- this breaks

    // Disabled for has_one components
    if ($record && DataObject::getSchema()->hasOneComponent(get_class($record), $name)) {
        return false;
    }
    return true;
}

Using the upload field within a content block that uses inline editing will break this feature unfortunately. This is caused by EditFormFactory::namespaceFields() which changes the field names.

protected function namespaceFields(FieldList $fields, array $context)
{
    $elementID = $context['Record']->ID;

    foreach ($fields->dataFields() as $field) {
        $namespacedName = sprintf(self::FIELD_NAMESPACE_TEMPLATE ?? '', $elementID, $field->getName());
        $field->setName($namespacedName);// <------ field name change
    }
}

This will change for example Image to PageElements_153_Image. This will break the auto-detection feature of the UploadField as it can no longer recognise the field by name, so it falls back to default.

Workaround

This is my workaround - sublcass upload field and override the getIsMultiUpload() method.

/**
 * Can't use directly @see EditFormFactory::FIELD_NAMESPACE_TEMPLATE
 */
private const NAMESPACE_PREFIX = 'PageElements_';

/**
 * Copied from @see UploadField::getIsMultiUpload()
 * Fixed the issue when this field is used in the elemental inline editor context
 * The field names are prefixed which breaks the auto-detection feature of this field
 * Issue caused by @see EditFormFactory::namespaceFields()
 * GitHub issue raised: https://github.com/silverstripe/silverstripe-elemental/issues/1104
 *
 * @return bool
 */
public function getIsMultiUpload(): bool
{
    if ($this->multiUpload !== null) {
        // Explicit settings
        return (bool) $this->multiUpload;
    }

    // Guess from record
    $record = $this->getRecord();
    $name = $this->getName();
    $name = $this->removeElementalNamespace($name);

    // Disabled for has_one components
    if ($record && DataObject::getSchema()->hasOneComponent($record::class, $name)) {
        return false;
    }

    return true;
}

private function removeElementalNamespace(string $fieldName): string
{
    if (mb_strpos($fieldName, self::NAMESPACE_PREFIX) === 0) {
        // Extract the last segment of the namespaced field which is the original field name
        $segments = explode('_', $fieldName);

        return array_pop($segments);
    }

    return $fieldName;
}

Test for this:

class UploadFieldTest extends SapphireTest
{
    /**
     * @param string $fieldName
     * @param string $expected
     * @return void
     * @throws ReflectionException
     * @dataProvider fieldNamesDataProvider
     */
    public function testRemoveElementalNameSpace(string $fieldName, string $expected): void
    {
        $field = UploadField::create('Test', 'Test');

        /** @see UploadField::removeElementalNamespace() */
        $removeElementalNamespaceMethod = new ReflectionMethod($field, 'removeElementalNamespace');
        $removeElementalNamespaceMethod->setAccessible(true);

        $result = $removeElementalNamespaceMethod->invoke($field, $fieldName);
        $this->assertEquals($expected, $result, 'We expect a specific sanitised value');
    }

    public function fieldNamesDataProvider(): array
    {
        return [
            'standard field name' => [
                'Image',
                'Image',
            ],
            'namespaced field name' => [
                'PageElements_153_Image',
                'Image',
            ],
        ];
    }
}

Acceptance criteria

• Review the weirdness around elemental's field naming convention and try to identify alternative ways of getting a multi file upload field working.
• If there's no elegant solution we can put directly in the CMS, document the limitation and alternative ways developers can bypass this problem.
• Otherwise, implement a fix to allow the upload field to auto detect if it's pointed at a HasMany relation.

PRs

• FIX Apply multiupload auto-detection for upload fields #1108

[emteknetnz]

Linked PR has been merged, it will be tagged automatically