Pass fixed variable from route to controller in La

2019-05-21 00:37发布

问题:

I'm trying to pass a variable through my route to my controller, but I have multiple routes (categories) leading to the same controller i.e.

Route::get('/category1/{region}/{suburb?}', 'SearchController@search');
Route::get('/category2/{region}/{suburb?}', 'SearchController@search');

Making /category1, 2, etc. to be a parameter /{category} is not an option and I don't want to make separate controller function for each category.

How do I send the first segment of the url to my search controller? i.e. category1 or category2?

At present controller is as follows:

public function search($region, $suburb = null) { }

Thanks!

回答1:

You can specify a mask for your {category} parameter so that it must fit the format "category[0-9]+" in order to match the route.

Route::get('/{category}/{region}/{suburb?}', 'SearchController@search')
    ->where('category', 'category[0-9]+');

Now, your example url (from the comments) www.a.com/var1/var2/var3 will only match the route if var1 matches the given category regex.

More information can be found in the documentation for route parameters here.

Edit

Yes, this can work with an array of string values. It is a regex, so you just need to put your array of string values into that context:

Route::get('/{category}/{region}/{suburb?}', 'SearchController@search')
    ->where('category', 'hairdresser|cooper|fletcher');

Or, if you have the array built somewhere else:

$arr = ['hairdresser', 'cooper', 'fletcher'];

// run each array entry through preg_quote and then glue
// the resulting array together with pipes
Route::get('/{category}/{region}/{suburb?}', 'SearchController@search')
    ->where('category', implode('|', array_map('preg_quote', $arr)));

Edit 2 (solutions for original request)

Your original question was how to pass the hardcoded category segment into the controller. If, for some reason, you didn't wish to use the solution above, you have two other options.

Option 1: don't pass the value in, just access the segments of the request in the controller.

public function search($region, $suburb = null) {
    $category = \Request::segment(1);
    dd($category);
}

Option 2: modify the route parameters using a before filter (L4) or before middleware (L5).

Before filters (and middleware) have access to the route object, and can use the methods on the route object to modify the route parameters. These route parameters are eventually passed into the controller action. The route parameters are stored as an associative array, so that needs to be kept in mind when trying to get the order correct.

If using Laravel 4, you'd need a before filter. Define the routes to use the before filter and pass in the hardcoded value to be added onto the parameters.

Route::get('/hairdresser/{region}/{suburb?}', ['before' => 'shiftParameter:hairdresser', 'uses' => 'SearchController@search']);
Route::get('/cooper/{region}/{suburb?}', ['before' => 'shiftParameter:cooper', 'uses' => 'SearchController@search']);
Route::get('/fletcher/{region}/{suburb?}', ['before' => 'shiftParameter:fletcher', 'uses' => 'SearchController@search']);

Route::filter('shiftParameter', function ($route, $request, $value) {
    // save off the current route parameters    
    $parameters = $route->parameters();
    // unset the current route parameters
    foreach($parameters as $name => $parameter) {
        $route->forgetParameter($name);
    }

    // union the new parameters and the old parameters
    $parameters = ['customParameter0' => $value] + $parameters;
    // loop through the new set of parameters to add them to the route
    foreach($parameters as $name => $parameter) {
        $route->setParameter($name, $parameter);
    }
});

If using Laravel 5, you'd need to define a new before middleware. Add the new class to the app/Http/Middleware directory and register it in the $routeMiddleware variable in app/Http/Kernel.php. The logic is basically the same, with an extra hoop to go through in order to pass parameters to the middleware.

// the 'parameters' key is a custom key we're using to pass the data to the middleware
Route::get('/hairdresser/{region}/{suburb?}', ['middleware' => 'shiftParameter', 'parameters' => ['hairdresser'], 'uses' => 'SearchController@search']);
Route::get('/cooper/{region}/{suburb?}', ['middleware' => 'shiftParameter', 'parameters' => ['cooper'], 'uses' => 'SearchController@search']);
Route::get('/fletcher/{region}/{suburb?}', ['middleware' => 'shiftParameter', 'parameters' => ['fletcher'], 'uses' => 'SearchController@search']);

// middleware class to go in app/Http/Middleware
// generate with "php artisan make:middleware" statement and copy logic below
class ShiftParameterMiddleware {
    public function handle($request, Closure $next) {
        // get the route from the request
        $route = $request->route();

        // save off the current route parameters
        $parameters = $route->parameters();
        // unset the current route parameters
        foreach ($parameters as $name => $parameter) {
            $route->forgetParameter($name);
        }

        // build the new parameters to shift onto the array
        // from the data passed to the middleware
        $newParameters = [];
        foreach ($this->getParameters($request) as $key => $value) {
            $newParameters['customParameter' . $key] = $value;
        }

        // union the new parameters and the old parameters
        $parameters = $newParameters + $parameters;
        // loop through the new set of parameters to add them to the route
        foreach ($parameters as $name => $parameter) {
            $route->setParameter($name, $parameter);
        }

        return $next($request);
    }

    /**
     * Method to get the data from the custom 'parameters' key added
     * on the route definition.
     */
    protected function getParameters($request) {
        $actions = $request->route()->getAction();
        return $actions['parameters'];
    }
}

Now, with the filter (or middleware) setup and in use, the category will be passed into the controller method as the first parameter.

public function search($category, $region, $suburb = null) {
    dd($category);
}