[Bug] Render Create/Edit view of model with json() attribute on MariaDB

[gerard-insurnet]

Bug report

Please note: All issues must be submitted in English. If not, they will be closed automatically.

What I did

I opened the edit view of a CRUD model which has an attribute of type json().

What I expected to happen

Render the view correctly, but instead i got the following error from the file ...\resources\views\vendor\backpack\crud\fields\textarea.blade.php:

htmlspecialchars(): Argument #1 ($string) must be of type string, array given

What happened

I have a model which migration has an attribute type json(). Running it on a MariaDB database, it's type is created as longtext. As my model has a cast for the attribute to array, and i have defined the setupUpdateOperation() function just using CRUD::setFromDb(), it's trying to render the field as textarea using as value an array from the casting.

What I've already tried to fix it

If i have my database as MySQL it works, but as MariaDB in latest versions defines the field as longText and not native json, it doesn't.

Is it a bug in the latest version of Backpack?

Yes.

Backpack, Laravel, PHP, DB version

When I run php artisan backpack:version the output is:

PHP VERSION:

8.3.22

PHP EXTENSIONS:

Core, bcmath, calendar, ctype, date, filter, hash, iconv, json, SPL, pcre, random, readline, Reflection, session, standard, mysqlnd, tokenizer, zlib, libxml, dom, PDO, opens
sl, SimpleXML, xml, xmlreader, xmlwriter, curl, fileinfo, gd, intl, mbstring, exif, mysqli, Phar, pdo_mysql, pdo_sqlite, soap, sodium, sqlite3, xsl, zip, xdebug

LARAVEL VERSION:

12.15.0.0

BACKPACK PACKAGE VERSIONS:

backpack/activity-log: 2.0.7
backpack/basset: 1.3.9
backpack/crud: 6.8.3
backpack/generators: v4.0.7
backpack/permissionmanager: 7.2.1
backpack/pro: 2.2.22
backpack/theme-tabler: 1.2.18

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--
Justin Case
The Backpack Robot

[backpack-ai-bot]

This issue is a known problem when using MariaDB with Backpack and Laravel for JSON fields. MariaDB (especially in certain versions) does not support the native JSON column type as MySQL does; instead, it creates the column as LONGTEXT. When you cast the attribute as an array in your model and use Backpack's setFromDb(), Backpack tries to render the field as a textarea, but the value is an array (from the cast), not a string, leading to the error:

htmlspecialchars(): Argument #1 ($string) must be of type string, array given

This happens because the textarea field expects a string, but receives an array due to the model casting. The root cause is that setFromDb() infers the field type from the database column type, and since MariaDB uses LONGTEXT for JSON, Backpack treats it as a text field, not as a JSON/array field.

Workarounds and Recommendations:

• Manually Define Fields: Instead of relying on setFromDb(), manually define your fields in the controller using addField() and specify the correct field type (such as 'table' or 'array') for your JSON attributes. This avoids the automatic (and incorrect) inference from the LONGTEXT type.
• Be Cautious with Model Casting: If you cast the attribute as array or object, ensure the corresponding Backpack field can handle arrays/objects. The textarea field cannot.
• MariaDB vs MySQL: This issue does not occur with MySQL, as it supports native JSON columns and Backpack can infer the correct field type.

This behavior and its workaround are discussed in several issues, where users report that MariaDB's handling of JSON columns as LONGTEXT leads to Backpack rendering problems when using setFromDb() and model casting. The recommended solution is to avoid setFromDb() for such fields and define them explicitly in your CRUD controller. For example:

$this->crud->addField([
    'name' => 'your_json_field',
    'type' => 'table', // or 'array', depending on your data structure
    // other options...
]);

Array to string conversion on show template

If you need to support both MariaDB and MySQL, always define your JSON fields explicitly in Backpack and avoid relying on automatic field type detection for these columns.

If you need more details or a specific code example, let me know!

ℹ️ Please note our AI Bot does not reply to follow-ups, this will be the only AI answer in this thread. If the AI helped you find the answer, please mark it as answered or write details below so it can learn. Then close the conversation. If not, please give more information for when a human reads this. ℹ️

Relevant sources:

Github Issue (closed): [Bug] Checking column exists in database doesn't work with MariaDB
Github Issue (closed): [Bug] Table field doesn't work with objects
Github Issue (open): [Bug] Null is being populated as a String if MariaDB used
Github Issue (closed): Crud field type "table" problem
Github Issue (closed): How to show JSON fields from the database?
Github Issue (closed): getTranslations() return string and expecting array
Github Issue (closed): Malformed JSON in "table" field when casting
Github Issue (closed): Errors if cast json field to array as Docs say
Github Issue (closed): Using multidimensional arrays in fake fields
Github Issue (closed): Model attribute cast problem
Github Issue (closed): Array to string conversion on show template
Github Issue (closed): [Bug] Database field type JSON (casted as array) tries to use PRO TABLE component as default field