实现地点访问/取消访问功能报错：Trying to get property of non-object

Alright, let's walk through exactly what's causing that error and fix it up step by step. The root issue is that your place_id is coming through as null in the controller, which breaks subsequent code that tries to access properties on a non-existent Place object. Here's how to fix it:

1. Fix the AJAX Parameter Mismatch & Unreliable DOM Selection #

First, your JavaScript is sending the parameter as place_id, but your controller is trying to fetch $request['placeId'] (notice the camelCase vs snake_case mismatch). That's why $place_id is null right off the bat.

Also, your current way of grabbing placeId via event.target.parentNode.parentNode is fragile—if the DOM structure changes even a little, this will break. Use jQuery's closest() method to reliably find the parent element with the data-place_id attribute instead.

Here's the corrected AJAX code:

var token = '{{ Session::token() }}';
var urlVisit = '{{ route('visitss') }}';

$('.visit').on('click', function(event){
    event.preventDefault();
    // Grab the place ID from the closest parent with the data attribute
    var placeId = $(this).closest('[data-place_id]').data('place_id');
    
    // Add a quick check to avoid sending invalid requests
    if (!placeId) {
        console.error("Couldn't find a valid place ID for this button");
        return;
    }

    $.ajax({
        method: 'POST',
        url: urlVisit,
        data: {
            place_id: placeId, // Match the snake_case parameter name the controller expects
            _token: token
        }
    })
    .done(function(response) {
        // Optional: Add UI feedback (e.g., toggle a "visited" class on the button)
        $(this).toggleClass('visited');
        console.log(response.status);
    })
    .fail(function(xhr) {
        console.error("Toggle visit failed:", xhr.responseText);
    });
});

2. Fix Controller Logic Errors #

Your controller has two critical issues that contribute to the error:

• You're trying to access $place->id even when $place is null (when $place_id is invalid)
• You're assigning Auth::user() directly to $visited->user_id—this should be the user's ID, not the entire user object

Here's the cleaned-up, error-resistant controller code:

use Illuminate\Http\Request;
use App\Models\Place;
use App\Models\Visit;
use Illuminate\Support\Facades\Auth;

public function toggleVisit(Request $request)
{
    // Get the place ID from the request (use input() for safer access)
    $place_id = $request->input('place_id');

    // Validate we received a valid place ID first
    if (!$place_id) {
        return response()->json(['error' => 'Invalid place ID provided'], 400);
    }

    // Find the place—if it doesn't exist, return an error
    $place = Place::find($place_id);
    if (!$place) {
        return response()->json(['error' => 'Place not found'], 404);
    }

    // Get the authenticated user (add auth middleware to your route to ensure this isn't null)
    $user = Auth::user();
    if (!$user) {
        return response()->json(['error' => 'You must be logged in to toggle visits'], 401);
    }

    // Check if the user already visited this place
    $visited = $user->visitors()->where('place_id', $place_id)->first();

    if ($visited === null) {
        // Create a new visit record
        $visited = new Visit();
        $visited->user_id = $user->id; // Assign the user's ID, not the object
        $visited->place_id = $place->id;
        $visited->save();
        return response()->json(['status' => 'visited']);
    } else {
        // Delete the existing visit record
        $visited->delete();
        return response()->json(['status' => 'unvisited']);
    }
}

3. Quick Additional Checks #

• Model Fillables: Make sure your Visit model allows mass assignment for the required fields. Add this to your Visit model:

  protected $fillable = ['place_id', 'user_id'];
  

• Route Middleware: Ensure your visitss route uses the auth middleware to prevent unauthenticated users from hitting this endpoint. Example route definition:

  Route::post('/toggle-visit', [YourController::class, 'toggleVisit'])->name('visitss')->middleware('auth');
  

• Database Table: Double-check your visits table (note: table names are typically plural) has place_id and user_id as unsigned integer fields, ideally set as foreign keys to places.id and users.id.

内容的提问来源于stack exchange，提问作者detinu20