Level 75
'sometimes|exists:foobar,id'
Docs: https://laravel.com/docs/8.x/validation#validating-when-present
Always use ConvertEmptyStringsToNull middleware.
Nov 14, 2020
6
Level 9
Validate select dropdown with potential empty string
Assuming I have a form with this select tag:
<select name="foobar">
<option value="">Select:</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
I want this to be optionally empty (i.e. the first option), or to validate that the value selected exists in the database. But this validation option doesn't work:
'nullable|exists:foobar,id'
It will validate any selected option ok, but not the top (empty) option, I guess because an empty string is not null. I know there's a ConvertEmptyStringsToNull middleware but I'd rather not activate it if possible. What's the best practice here?
Level 75
So then it's your problem not mine.
Level 9
Sorry Michal, I wrote a confused reply based on a misunderstanding on my side, so I've deleted it.
I do have that middleware activated. However even with this sometimes validation rule, I still get the "The selected foobar is invalid" error message.
I am using Livewire, if that makes a difference.
Level 9
For anyone else encountering this problem, it seems it's a "feature" of Livewire:
Level 75
I don't use Livewire so I don't know but this will work with ConvertEmptyStringsToNull and for nullable it's neccesary. In classic Laravel app.
'nullable|exists:foobar,id'
Docs: https://laravel.com/docs/8.x/validation#a-note-on-optional-fields
Level 9
Yes, 'nullable|exists:foobar,id' is what I wrote in my question.
Seems it's a Livewire issue.
Please or to participate in this conversation.