使用 laravel 中的 controller 将数据从数据库传递到刀片视图

Question

I found several ways to do what I need to do, the first way was using the rounting using the web.php file. But according to serveral posts this creates vulnerabilities in the application. So I found out the correct usage is with a controller that manages the database queries.

I created a controller, named EventsController and put this into it:

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class EventsController extends Controller
{
    public function index()
    {
        $events = DB::table('eventaries')->select('id','coursname','start', 'end', 'category')->get();

        return view('components.course-list')->with('eventaries', $events);
    }
}

the blade is inside the folder: /resources/views/components/course-list.blade.php

Inside the blade I use this code:

<div class="px-6 py-20">
    <div class="max-w-7xl mx-auto">
        <!-- Course List -->

        {{ $events->coursname}}


    </div>
</div>

But I get the error:

Undefined variable $events (View: D:\laragon\www\censored\resources\views\components\course-list.blade.php)

Answer 1

->with('eventaries', $events) means that you are passing the value of $events as eventaries. So in the blade you need to access it using $eventaries instead. So now blade code would be:

    <div class="px-6 py-20">
    <div class="max-w-7xl mx-auto">
        <!-- Course List -->

        {{ $eventaries->coursname}}


    </div>
</div>

Answer 2

You have given 'eventaries' as the name for events. So you can only access it with $eventaries within the view, not as events.

Answer 3

you are passing to the view the value using the "with" method, and it does it like a value/key pair (->with($key, $value)). In your case you declare it like

return view('components.course-list')->with('eventaries', $events);

so, in the view you can access the value through the $eventaries, not the $events. Also, the query result is a collection and you will need to loop it to get each item

<div class="px-6 py-20">
    <div class="max-w-7xl mx-auto">
        <!-- Course List -->
        @foreach($eventaries as $event)
        {{ $event->coursename }}
        @endforeach
    </div>
</div>

Answer 4

When using the with method on a view the first argument (key) becomes the name of the variable in the view and the second argument (value) becomes it's value.

This means you need to use $eventaries in your view instead of $events or rename the key in your controller return view('components.course-list')->with('events', $events); .

Also, I'm not sure about defining the action directly in the routes file causes vulnerabilities. I just think that the routes file, which is often the first entry point for developers when exploring a Laravel app, becomes hard to read/manage.

Answer 5

What caused the issue?
The issue of this question was created because the router was never accessing the controller I created. I added the following code to my router to access the controller:

Route::get('/kursangebote/{course}', ['App\Http\Controllers\EventaryController', 'index'])->name('course.list-list');

In there I added the logic I wanted.

['App\Http\Controllers\EventaryController', 'index']

App\Http\Controllers\EventaryController is the controller I use, and index the function inside the controller I need to call. It might be a better Idea to use Eloquent for this https://laravel.com/docs/8.x/eloquent