Various Issues With Currency Field

[MannikJ]

• Laravel Version: 11.39.1
• Nova Version: 5.1.5
• PHP Version: 8.3.15
• Database Driver & Version: MariaDB 11.6.2
• Operating System and Version: Linux Mint 21.3
• Browser type and version: Google Chrome Version 132.0.6834.83 (Official Build) (64-bit)

Description:

The Currency field in Nova has several issues, primarily related to handling null or empty string values and dynamically setting the currency value. Below are the detailed issues observed:

1. Cannot Be Null Anymore:

   • While it worked in Nova v4, stricter typing in Nova v5 prevents passing null to the currency() modifier.
   • Passing an empty string ('') to the currency() modifier is also not accepted.
   • We can add the nullable() modifier without any effect
   • Leaving out the currency() modifier completely causes the field to fall back to USD, but it will not allow null values.

2. Dynamic Currency Values:

   • When the currency is fetched dynamically from the database, the filterable() modifier cannot be used. Nova uses an empty instance of the resource without database attributes to create the filters, resulting in the following exception:

     Laravel\Nova\Fields\Currency::resolveCurrencySymbol(): Return value must be of type string, null returned {"userId":1,"exception":"[object] (TypeError(code: 0): Laravel\\Nova\\Fields\\Currency::resolveCurrencySymbol(): Return value must be of type string, null returned at /var/www/html/vendor/laravel/nova/src/Fields/Currency.php:207)

I found a workaround for my case that might help to better understand the problem:

class Wallet extends Resource
{
    public function fields(NovaRequest $request)
    {
        $currencyField = Currency::make('Balance')
            ->exceptOnForms()
            ->sortable()
            ->nullable()
            ->filterable();

        if ($this->owner) {
            $currencyField->currency($this->owner->currency);
        }

        return [
            ID::make()->sortable(),
            BelongsTo::make('Owner', 'owner', User::class)
                ->searchable()
                ->filterable(),
            $currencyField,
            HasMany::make('Transactions', 'transactions', WalletTransaction::class),
        ];
    }
}

This workaround ensures the currency() modifier is not set when the model is empty, allowing the field to fall back to its default value (`USD). Once the fields are evaluated for actual resources, the currency can be resolved dynamically.

Suggested Fixes

• Allow the currency() modifier to accept null or an empty string
• Adjust the resolveCurrencySymbol() method to handle null values gracefully, especially when using filterable().
• Provide better support for dynamic currency values sourced from database attributes

[crynobone]

There many requirement in Currency that explicitly required currency to be defined, such as:

• Resolving the correct currency symbol
• Resolving the correct minimum currency steps
• Resolving the correct fraction for currency.

Moving this to Idea for now.

[crynobone]

Targetting this for 5.2.0 release.

[MannikJ]

At least that filterable is not usable when the currency needs to be resolved from the database, I would consider a bug. The error message in this case is not meaningful at all and requires tedious troubleshooting to find the cause. I don't think this setup is uncommon - rather the most widely used.

[crynobone]

5.2.0 is due early february

[crynobone]

Released