Laravel中RedirectResponse的with()方法及withDemo语法疑问

Hey there! I totally get why this might feel confusing at first—those "magic" methods seem like they come out of nowhere. Let me break down exactly how they work, using the withDemo() example you mentioned.

It's All About PHP Magic Methods #

Laravel leverages PHP's __call() magic method to make these shorthand methods work. Here's the breakdown:

When you call something like return view('name')->withDemo($demo);, PHP checks if the withDemo() method exists in the View class. Since it doesn't (Laravel doesn't define a method for every possible withXxx variation), it triggers the __call() method that Laravel has built into the View (and RedirectResponse) class.

What __call() Does Behind the Scenes #

The __call() method takes the name of the method you tried to call (withDemo) and strips off the "with" prefix. It then converts the remaining part (in this case, "Demo") to lowercase, turning it into the variable key demo.

After that, it simply calls the standard with() method for you, passing the lowercase key and the value you provided. So:

return view('name')->withDemo($demo);

is exactly equivalent to:

return view('name')->with('demo', $demo);

Same Logic Applies to RedirectResponse #

You mentioned RedirectResponse's with() method too—this magic shorthand works there identically! For redirects, withXxx($value) stores the data in the session as flash data (just like the regular with() method does), so you can access it on the next request using session('xxx').

Why Use This Shorthand? #

It's purely a readability and convenience feature. Instead of writing ->with('user_name', $username), you can write ->withUserName($username) which flows a bit more naturally in code, especially when you're passing multiple pieces of data.

内容的提问来源于stack exchange，提问作者Rahul