how to make a update page with hasMany relatioins in laravel - php

Question

I'm trying to create a form to update a model which has one to many relations. The structure is like
item => {[arg1, arg2], [arg1, arg2], [arg1, arg2]}
Each related model has two fields to be updated. I used the code below but I don't know how to code the controller side.
#extends('app')
#section('content')
{!! Form::open(array('route' => array('Topic.update', $topic->id), 'method' => 'PATCH')) !!}
{!! Form::label('title', 'Title') !!}
{!! Form::text('title', $topic->title, array('maxlength' => 250)) !!}
#foreach($topic->pairs as $key=>$value)
<div>
{!! Form::label('title', 'Pair ' . $key . ': ') !!}
{!! Form::text('a' + $key, $value->arg1) !!}
{!! Form::text('b' + $key, $value->arg2) !!}
</div>
#endforeach
{!! Form::submit() !!}
{!! Form::close() !!}
#endsection
When I dd($response->all()), it shows below:
array:9 [▼
"_method" => "PATCH"
"_token" => "dInpiSa6O2KIMftFnICQtVM873nUF2Zp2HlzeN4S"
"title" => "Actors and Movies"
0 => "Rain Man"
1 => "Rush Hour"
2 => "Edward Scissorhands"
3 => "Titanic"
4 => "The Devil Wears Prada"
5 => "Fast & Furious"
]
The related items are not pairs but only arg1. So how should I code hasMany model? Thanks

Answer 1

The + sign in PHP is not used for concatenation of strings. It is math operator. To concatenate strings you should use dot (.).
So change your code like this:
Form::text('a' . $key, $value->arg1)
Form::text('b' . $key, $value->arg2)
Because previously you were calculating the sum of a and $key, thats why you get numerical keys in the request.
If you wish to access your pairs in array, from the form request you can change the inputs to be arrays, like this:
Form::text('items[' . $key . '][arg1]', $value->arg1)
Form::text('items[' . $key . '][arg2]', $value->arg2)
With last example the request will look like this:
items => [
[ arg1, arg2 ],
[ arg1, arg2 ],
....
]