How to compress the output of an HTML in Laravel?

Assuming you use Laravel 5.2 you can use the render method, then in Controller it would look something like, this is an example just to show how to use it, I changed the contents of $ data by a new output with return :

<?php

namespace App\Http\Controllers;

use App\User;
use App\Http\Controllers\Controller;

class UserController extends Controller
{
    public function home()
    {
        $v = view('welcome')->render(function ($obj, $data) {
            return 'Hello world!';
        });

        return $v;
    }
}

So just merge to the other link code getting something like:

function reduzirHtml($data)
{
    $search = array(
        '/\>[^\S ]+/s',  // strip whitespaces after tags, except space
        '/[^\S ]+\</s',  // strip whitespaces before tags, except space
        '/(\s)+/s'       // shorten multiple whitespace sequences
    );

    $replace = array(
        '>',
        '<',
        '\1'
    );

    return preg_replace($search, $replace, $data);
}

class UserController extends Controller
{
    public function home()
    {
        return view('welcome')->render(function ($obj, $data) {
             return reduzirHtml($data);
        });
    }

    public function about()
    {
        return view('welcome')->render(function ($obj, $data) {
             return reduzirHtml($data);
        });
    }
}

If you change the function to function reduzirHtml($obj, $data) you can call directly:

return view('welcome')->render("\App\Http\Controllers\reduzirHtml");

Or you can even move the reduzirHtml function to a file or method in a class and call it as in the example:

//Função
return view('welcome')->render("\reduzirHtml");

//Classe
return view('welcome')->render("\Namespace\Classe\reduzirHtml");

To capture all HTML output from the application, you can also use a Middleware , which will preprocess this.

First run the command:

 php artisan make:middleware HtmlCompressor

Next, leave the handle method as in the example below:

namespace App\Http\Middleware;

use Closure;

/**
 * 
 * @author Wallace de Souza Vizerra <[email protected]>
 * 
 * */
class HtmlCompressor
{

    public function handle()
    {
        $response = $next($request);

        // Verifica se a saída é HTML

        if (str_contains($response->headers->get('content-type'), 'text/html')) {

            $search = [
                '/\>[^\S ]+/s',  // strip whitespaces after tags, except space
                '/[^\S ]+\</s',  // strip whitespaces before tags, except space
                '/(\s)+/s'       // shorten multiple whitespace sequences
            ];

            $replace = [
                '>',
                '<',
                '\1'
            ];

            $response->setContent(preg_replace($search, $replace, $response->getContent()));

            return $response;

        }

        return $response;
    }
}

In the App\Http\Kernel class of your application, you will add this middewlare that we create in the $middleware property:

protected $middleware = [
   // outros middlewares
   \App\Http\Middleware\HtmlCompressor
];