Getting "Laravel\Nova\Fields\BelongsTo::buildMorphableQuery does not exist" on a Polymorphic resource

[lukejwatts]

• Laravel Version: 9.52.16
• Nova Version: Version: 4.22.2 (Silver Surfer)
• PHP Version: 8.2.17
• Database Driver & Version: MySQL - Ver 8.0.36 for Win64 on x86_64 (MySQL Community Server - GPL)
• Operating System and Version: Windows 10
• Browser type and version: MS Edge - Version 126.0.2592.102 (Official build) (64-bit)
• Reproduction Repository: Todo

Description:

I have a polymorhic table which has a belongs to relationship on it also. When I attempt to select the resource (project_phaseable_type) from the dropdown I get the following error:

I'm assuming it's because of the BelongsTo field in my fields array? Or I've set something up wrong (Please see the code snippets below for migrations, model and resource definitions)

Am I using the wrong morphTo/Many etc? The models relationships all work as expected for my use case which is many-to-many from the example, but it's actually a one-to-one relationship in practice.

Polymorphic Migration Schema

create_project_phases_table migration:

Schema::create('project_phases', function (Blueprint $table) {
    $table->id();
    $table->unsignedBigInteger('phase_id');
    $table->morphs('project_phaseable');
    $table->timestamps();

    // Ensures we can only have one phase per "project_phaseable_type"
    $table->unique(['phase_id', 'project_phaseable_type', 'project_phaseable_id'], 'project_phaseable_polymorphic_unique');

    $table->foreign('phase_id')->references('id')->on('phases');
});

ProjectPhase model

class ProjectPhase extends Model
{
    use HasFactory;

    /**
     * Get the parent project_phaseable model (family, estate, property).
     */
    public function projectPhaseable()
    {
        return $this->morphTo();
    }

    public function phase(): BelongsTo
    {
        return $this->belongsTo(Phase::class, 'phase_id', 'id');
    }
}

ProjectPhase resource (fields)

public function fields(NovaRequest $request)
    {
        return [
            ID::make()->sortable(),
            BelongsTo::make('Phase', 'projectPhaseable', Phase::class),
            MorphTo::make('Project Phaseable', 'projectPhaseable')->types([
                Estate::class,
                Family::class,
                Property::class,
            ])->default(Estate::class),
        ];
    }

Detailed steps to reproduce the issue on a fresh Nova installation:

1. Setup a polymorphic relationship as per the example here in the docs: https://laravel.com/docs/10.x/eloquent-relationships#many-to-many-polymorphic-relations
2. Add BelongsTo field in you Taggable resource

Thanks in advance!

Luke

[crynobone]

BelongsTo::make('Phase', 'projectPhaseable', Phase::class),

Bad relationship name here.

[lukejwatts]

BelongsTo::make('Phase', 'projectPhaseable', Phase::class),

Bad relationship name here.

So should it be BelongsTo::make('Phase', 'projectPhase', Phase::class) or something else?

[crynobone]

From the documentation , and you can also refer to https://laravel.com/docs/11.x/eloquent-relationships#one-to-one-defining-the-inverse-of-the-relationship