The method this.emitFieldValue not works for belongsTo

[leandrogehlen]

• Laravel Version: 9.52.5
• Nova Version: 4.22.2
• PHP Version: 8.1.2
• Database Driver & Version: mysql

Description:

Building a new custom field component i need update BelongsTo relation via vue component.

using the this.emitFieldValue works fine with simple field (Text, Number ...) but for BelongsTo component
when set key value (this.emitFieldValue('city', 1)) should be displayed the city name.

update-has-one-via-vue-component.mp4

[crynobone]

BelongsTo field doesn't support this usage, you should use Dependent Field to trigger update to BelongsTo field.

[leandrogehlen]

Dependent fields has the same issue.

I have tried

BelongsTo::make(__('City'), 'city', City::class)
    ->searchable()
    ->withoutTrashed()
    ->rules('required')
    ->dependsOn(['postcode'], function (BelongsTo $field, NovaRequest $request, FormData $formData) {
       $field->value = 3550308;
   }),

But it is not works.

I believe that the problem is the same for both scenarios (dependent fields and emitFieldValue. I think that is a necessary feature and is a simple modification. It's a little strange that emitFieldValue works for all other fields except BelongsTo. This feature would be very helpful building more complex routines and custom components.

[crynobone]

https://github.com/laravel/nova-dusk-suite/blob/e7f23da12f05d15dd46ad5fc524afa049bbda1bd/app/Nova/Post.php#L64-L81

[leandrogehlen]

Ok, it works for default because it's a creation operation
But when is editing a resource the issue happens

I have detected the problem in initializeComponent method,
line: this.selectedResourceId = this.currentField.belongsToId

initializeComponent() {
   this.withTrashed = false  

  this.selectedResourceId = this.currentField.value // currentField.value is correct

  if (this.editingExistingResource) {
     // If a user is editing an existing resource with this relation
     // we'll have a belongsToId on the field, and we should prefill
     // that resource in this field
     this.initializingWithExistingResource = true
      this.selectedResourceId = this.currentField.belongsToId // this change the new value defined in dependsOn closure
   } else if (this.creatingViaRelatedResource) {
      ...

[crynobone]

I believe this limitation has been fixed in the latest Laravel Nova 4 release.