Ajax定期工作。 有时POST请求返回错误419

Question

With the help of Laravel I create a multilingual website. When I switch languages using Ajax, sometimes I get an error. Javascript code:

$(document).ready(function(){
    $("#LanguageSwitcher").change(function(){
        var locale = $(this).val();
        var _token = $('meta[name="csrf-token"]').attr('content');

        $.ajax({
            url: "/language",
            type: 'POST',
            data: {locale: locale, _token: _token},
            datatype: 'json',
            beforeSend: function () {
                console.log('before send - ' + locale);
            },
            success: function (data) {
                console.log('success');
            },
            error: function (error) {
                console.log(error);
            },
            complete: function (data) {
                    window.location.reload(true);
            }
        });
    });
});

web.php:

Route::post('/language/', array(
    'before' => 'csrf', 
    'uses' => 'LanguageController@changeLanguage' 
));

Controller:

class LanguageController extends Controller
{
    public function changeLanguage(Request $request){
        if ($request->ajax()) {
            $request->session()->put('locale', $request->locale);
        }
    }
}

layout.blade.php:

<meta name="csrf-token" content="{{ csrf_token() }}">

        <select id="LanguageSwitcher" class="btn btn-outline-danger">
                <option>...code...</option>
                <option>...code...</option>
                <option>...code...</option>
        </select>

When I go through another browser everything works. It also works if I go through the incognito mode. Can this be due to the fact that I log in to the admin panel?

Answer 1

Put your ajax call like this.

req = $.ajax({
    type: "POST",
    url: "/search",
    data: {
        "locale": locale,
        "_token": "{{ csrf_token() }}",
    },
    dataType: "json",
    success: function(msg){

    }
});

Answer 2

As I saw your code. You passing csrf token in your request. the problem you face is, your csrf token is not being updated.

Let's say, you're not reloading your page, on first time your enter to your page, laravel give you csrf token which you providing to ajax through meta .

But after some time on the backend(laravel side). your csrf token is updated, but you don't have updated one in client-side.For get the updating one you need to reload the page.

so for this issue, you need to check whenever you get error status 419, request laravel for new csrf token(by making a new route get the csrf token from laravel helper csrf_token() return back to ajax) and update to your file. and send back that token to laravel with you request.

For updating newly token to your page

document.querySelector('meta[name=csrf-token]').setAttribute('content', res.data.csrf);

or you can refresh your token by reloading the page

Answer 3

add csrf token in meta tag in your blade view

   <meta name="csrf-token" content="{{ csrf_token() }}"/>

in your ajax function :

  $.ajax({
            url: '/search',
            headers: {'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')},
            type: 'POST',
            dataType: 'json',
            success: function(response) {

            },error:function(err){

            }
    });

Answer 4

I found the answer, but still did not understand how it works, explain who understands this. App\\Exceptions\\Handler.php

public function render($request, Exception $exception)
    {
        // code for updating token when session is expired
        if ($exception instanceof \Illuminate\Session\TokenMismatchException) {            
            return Redirect::back()->withErrors(['session' => 'Sorry, your session seems to have expired. Try Again']);
        }

        return parent::render($request, $exception);
    }