Added web-middleware based theme events

app/Http/Kernel.php

@@ -28,6 +28,7 @@ class Kernel extends HttpKernel
             \Illuminate\Session\Middleware\StartSession::class,
             \Illuminate\View\Middleware\ShareErrorsFromSession::class,
             \BookStack\Http\Middleware\VerifyCsrfToken::class,
+            \BookStack\Http\Middleware\RunThemeActions::class,
             \BookStack\Http\Middleware\Localization::class,
         ],
         'api' => [

app/Http/Middleware/RunThemeActions.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace BookStack\Http\Middleware;
+
+use BookStack\Facades\Theme;
+use BookStack\Theming\ThemeEvents;
+use Closure;
+
+class RunThemeActions
+{
+    /**
+     * Handle an incoming request.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @param  \Closure  $next
+     * @return mixed
+     */
+    public function handle($request, Closure $next)
+    {
+        $earlyResponse = Theme::dispatch(ThemeEvents::WEB_MIDDLEWARE_BEFORE, $request);
+        if (!is_null($earlyResponse)) {
+            return $earlyResponse;
+        }
+
+        $response = $next($request);
+        $response = Theme::dispatch(ThemeEvents::WEB_MIDDLEWARE_AFTER, $request, $response) ?? $response;
+        return $response;
+    }
+}

app/Theming/ThemeEvents.php

@@ -20,6 +20,27 @@ class ThemeEvents
      */
     const APP_BOOT = 'app_boot';
 
+    /**
+     * Web before middleware action.
+     * Runs before the request is handled but after all other middleware apart from those
+     * that depend on the current session user (Localization for example).
+     * Provides the original request to use.
+     * Return values, if provided, will be used as a new response to use.
+     * @param \Illuminate\Http\Request $request
+     * @returns \Illuminate\Http\Response|null
+     */
+    const WEB_MIDDLEWARE_BEFORE = 'web_middleware_before';
+
+    /**
+     * Web after middleware action.
+     * Runs after the request is handled but before the response is sent.
+     * Provides both the original request and the currently resolved response.
+     * Return values, if provided, will be used as a new response to use.
+     * @param \Illuminate\Http\Request $request
+     * @returns \Illuminate\Http\Response|null
+     */
+    const WEB_MIDDLEWARE_AFTER = 'web_middleware_after';
+
     /**
      * Commonmark environment configure.
      * Provides the commonmark library environment for customization