Column type: nested text

[nerbiz]

For an admin page with menu items (reorderable and nested) I needed more insight in the hierarchy of the items.
This column type shows the hierarchy with arrows, based on a parent_id column, so it works well with the Reorder Operation.

FYI: the arrow icon is from Line Awesome, which is already included by Backpack, so this code has no dependencies of its own.

Screenshot:

Put this code in resources/views/vendor/backpack/crud/columns/text_nested.blade.php:

@php
    namespace BackpackColumns;

    use Illuminate\Database\Eloquent\Model;

    if (! class_exists(TextNested::class)) {
        class TextNested {
            /**
             * @var array Reduces query amount by reusing models
             */
            protected static $modelCache = [];

            /**
             * Get a model from the cache, or query it
             * @param string $fqn Fully qualified class name
             * @param int    $id Model ID
             * @return Model|null
             */
            public static function getModel(string $fqn, int $id): Model|null
            {
                if (! isset(static::$modelCache[$fqn])) {
                    static::$modelCache[$fqn] = [];
                }

                if (! isset(static::$modelCache[$fqn][$id])) {
                    static::$modelCache[$fqn][$id] = $fqn::find($id);
                }

                return static::$modelCache[$fqn][$id];
            }
        }
    }

    // The column name where parent IDs are stored
    $column['parentIdColumn'] ??= 'parent_id';

    // Get all parent models, top-most first
    $parentModels = collect([]);
    $currentModel = $entry;
    $modelClass = get_class($entry);
    while ($currentModel->{$column['parentIdColumn']} !== null) {
        $parentModel = TextNested::getModel($modelClass, $currentModel->{$column['parentIdColumn']});
        if ($parentModel === null) {
            break;
        }

        $parentModels->prepend($parentModel);
        $currentModel = $parentModel;
    }
@endphp

{{-- Show each parent, followed by a newline with arrow --}}
@foreach($parentModels as $index => $parentModel)
    <span class="d-inline-block mb-2 text-muted">
        {{ $parentModel->{$column['name']} }}
    </span>
    <br>
    <i class="las la-level-up-alt text-muted"
       style="transform: rotate(90deg); margin-left: {{ ($index + 1) * 30 }}px"></i>
@endforeach

{{-- Show the item itself, after all possible parents --}}
{{ $entry->{$column['name']} }}

Usage:

protected function setupListOperation(): void
{
    CRUD::column('title')
        ->type('text_nested')
        // 'parent_id' is the default value,
        // so you could skip this
        ->parentIdColumn('parent_id');
}

[jcastroa87]

Hello @nerbiz

Thanks a lot for sharing this.

Cheers.

[tabacitu]

Yup - this looks really useful @nerbiz ! Thanks for sharing it. I think the use-case is pretty niche, so I don't see us including in the Backpack core... but I really think someone someday will need this, and the fact that you posted here will help them.

To help that person out - I would phrase this as "nested text column type", sure, but I would also call it "hierarchy" or "hierarchical" or "a column type for displaying nested items with their parents".

Just mentioned that so it's easy to find 😉

Thanks again for sharing @nerbiz !