Why can't I use method on relation in laravel? - laravel

Question

I wanna using method on relation in laravel but show error[Method Illuminate\Database\Eloquent\Collection::getMessage does not exist.].
Error was changed to Call to a member function getMessage() on null when I rewrite {{$item->board2->getMessage()}} to {{$item->aaaaaaaa->getMessage()}} so I think relation was succeed.
I have no Idea what's wrong.
please give me advice.
Board2.php(model)
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Board2 extends Model
{
protected $table = 'boards2';
protected $fillable = [
'person2_id',
'message'
];
public function person2()
{
return $this->belongsTo('App\Person2');
}
public function getMessage()
{
return $this->message;
}
}
Person2(model)
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Person2 extends Model
{
protected $table = 'people2';
protected $fillable = [
'name'
];
public function board2()
{
return $this->hasMany('App\Board2', 'person2_id');
}
}
View
<ul>
#foreach($items_p2 as $item)
<li>
{{$item->name}}
</li>
<li>
{{$item->board2->getMessage()}}
</li>
#endforeach
</ul>
controller
・
・
・
public function show2()
{
$items_p2 = Person2::all();
$data = [
'items_p2' => $items_p2
];
return view('Review.show2', $data);
}
migration files
class CreatePeople2Table extends Migration
{
/**
* Run the migrations.
*
* #return void
*/
public function up()
{
Schema::create('people2', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->timestamps();
});
}
<?php
use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;
class CreateBoards2Table extends Migration
{
/**
* Run the migrations.
*
* #return void
*/
public function up()
{
Schema::create('boards2', function (Blueprint $table) {
$table->increments('id');
$table->integer('person2_id');
$table->text('message');
$table->timestamps();
});
}

Answer 1

first:
in order to get the relation data you should load it first ...
$items_p2 = Person2::with('board2')-> all();
second: in your blade file
{{$item->board2->getMessage()}}
$item->board2 return a collection not a single board, so you should put it in foreach as well
#foreach($items_p2 as $item)
<li>
{{$item->name}}
</li>
<li>
#foreach($item->board2 as $board)
<li>
{{$item->board2->getMessage()}}
<li>
#endforeach
</li>
#endforeach
</ul>

Answer 2

Inside Board2.php(model) file, you have defined the method getMessage(), the method is loaded on the instance of the model and not the array of models (in Laravel's case, multiple models are loaded in a collection).
Inside Person2(model) file, you have defined the relation board2() which is linked to Board2 model via HasMany Relation. The catch is that HasMany relation, as the name suggests will load collection from the db and not a single instance of the model.
Try changing HasMany to HasOne inside Person2 model, your error should be resolved.

Answer 3

Accoring to the code you have written, each board2 record is connected to a single instance of person2, but on the other side, each person2 record is connected to a collection/array of board2 (not connected to single board2). This is the point keep in mind. Now let's proceed to next step.
Let's take a look in your view file. The code you wrote in view is
<ul>
#foreach($items_p2 as $item)
<li>
{{$item->name}}
</li>
<li>
{{$item->board2->getMessage()}}
</li>
#endforeach
</ul>
Here in $item->board2 , the board2 is not a single instance/record/model, rather it is a collection/array of multiple board2 instances/records/models. And each of that record/model will have the method "getmessage()" as you expected. So, the thing you have to do is, iterate through the records/models by making foreach to $item->board2, this way you will have the access to each single board2 record/model, then call the getMessage() method from that record/model. Let's modify the view code like this.
<ul>
#foreach($items_p2 as $item)
<li>
{{$item->name}}
</li>
<li>
#foreach( $item->board2 as $board )
{{$board->getMessage()}}
//this echo is just to break the line
echo '<br>';
#endforeach
</li>
#endforeach
</ul>
Hope it will work now. :)

Answer 4

You have to change this location. You write this in Person2 model
public function getMessage(){
return $this->message;
}