Why $post is not an object in the third code? - php

Question

I started learning Laravel today and I've ran into a problem.
There are 3 seperated posts. Each one has titles and I made an other title too which should be in the url of the page of the posts, for example:
something.com/posts/post_three instead of posts/3
With the id version (posts/3) it worked perfectly, but I tried to change the code so it will go to posts/post_three, but I keep getting the following error:
Trying to get property 'created_at' of non-object (View:
C:\xampp\htdocs\lsapp\resources\views\posts\show.blade.php)
I have the following codes which I've changed something in:
<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use App\Post;
class PostsController extends Controller
{
/**
* Display a listing of the resource.
*
* #return \Illuminate\Http\Response
*/
public function index()
{
$posts = Post::orderBy('urltitle', 'desc')->paginate(5);
return view('posts.index')->with('posts', $posts);
}
/**
* Show the form for creating a new resource.
*
* #return \Illuminate\Http\Response
*/
public function create()
{
//
}
/**
* Store a newly created resource in storage.
*
* #param \Illuminate\Http\Request $request
* #return \Illuminate\Http\Response
*/
public function store(Request $request)
{
//
}
/**
* Display the specified resource.
*
* #param int $id
* #return \Illuminate\Http\Response
*/
public function show($urltitle)
{
$post = Post::find($urltitle);
return view('posts.show')->with('post', $post);
}
/**
* Show the form for editing the specified resource.
*
* #param int $id
* #return \Illuminate\Http\Response
*/
public function edit($id)
{
//
}
/**
* Update the specified resource in storage.
*
* #param \Illuminate\Http\Request $request
* #param int $id
* #return \Illuminate\Http\Response
*/
public function update(Request $request, $id)
{
//
}
/**
* Remove the specified resource from storage.
*
* #param int $id
* #return \Illuminate\Http\Response
*/
public function destroy($id)
{
//
}
}
-
#extends('pages.layouts.app')
#section('content')
<h1 style="text-align: center">Posts</h1>
#if(count($posts) > 0)
#foreach($posts as $post)
{{$post->urltitle}}
<div class="card" style="padding-top: 8px">
<div class="card-body">
<h3>{{$post->title}}</h3>
<small>Written on: {{$post->created_at}}</small>
</div>
</div>
#endforeach
<div style="justify-content: center; display: flex;">{{$posts->links()}}</div>
#else
<p>No posts found</p>
#endif
#endsection
-
And here is the code which can't "recognise" $post
#extends('pages.layouts.app')
#section('content')
<div class="jumbotron text-center">
Go Back
<h1>{{$post->title}}</h1>
<div>{{$post->body}}</div>
<hr>
<small>Written at {{$post->created_at}}</small>
</div>
#endsection

Answer 1

This is where the error occurs:
public function show($urltitle)
{
$post = Post::find($urltitle); // <----
return view('posts.show')->with('post', $post);
}
The find() method will check for a primmary key (id by default) that hold the given value, so this both sentences are equal:
$post = Post::find($id);
// equals to:
$post = Post::where('id', $id)->first();
but given the fact that you are passing the urltitle instead of the $id, you should use a more generic approach:
$post = Post::where('urltitle', $urltitle)->first();
Also, as #devon said, you should check if a value is returned:
$post = Post::where('urltitle', $urltitle)->first();
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
if( ! $post)
{
// do something
}
or throw an error if the query returns nothing:
$post = Post::where('urltitle', $urltitle)->firstOrFail();
^^^^^^^^^^^^^