Introduce async local storage for request access, more view globals, and improved welcome view

src/views/ViewEngine.ts

@@ -1,8 +1,10 @@
 import {AppClass} from '../lifecycle/AppClass'
 import {Config} from '../service/Config'
 import {Container} from '../di'
-import {ErrorWithContext, UniversalPath} from '../util'
+import {ErrorWithContext, hasOwnProperty, Maybe, UniversalPath} from '../util'
 import {Routing} from '../service/Routing'
+import {RequestLocalStorage} from '../http/RequestLocalStorage'
+import {Request} from '../http/lifecycle/Request'
 
 /**
  * Abstract base class for rendering views via different view engines.
@@ -12,14 +14,19 @@ export abstract class ViewEngine extends AppClass {
 
     protected readonly routing: Routing
 
+    protected readonly request: RequestLocalStorage
+
     protected readonly debug: boolean
 
     protected readonly namespaces: {[key: string]: UniversalPath} = {}
 
+    protected readonly globals: {[key: string]: (req: Maybe<Request>) => any} = {}
+
     constructor() {
         super()
         this.config = Container.getContainer().make(Config)
         this.routing = Container.getContainer().make(Routing)
+        this.request = Container.getContainer().make(RequestLocalStorage)
         this.debug = (this.config.get('server.mode', 'production') === 'development'
                         || this.config.get('server.debug', false))
     }
@@ -56,7 +63,7 @@ export abstract class ViewEngine extends AppClass {
      * @protected
      */
     protected getGlobals(): {[key: string]: any} {
-        return {
+        const globals: {[key: string]: any} = {
             app: this.app(),
             config: (key: string, fallback?: any) => this.config.get(key, fallback),
             asset: (...parts: string[]) => this.routing.getAssetPath(...parts).toRemote,
@@ -65,6 +72,31 @@ export abstract class ViewEngine extends AppClass {
             route: (...parts: string[]) => this.routing.getAppUrl().concat(...parts).toRemote,
             hasRoute: (name: string) => this.routing.hasNamedRoute(name),
         }
+
+        const req = this.request.get()
+        if ( req ) {
+            globals.request = () => req
+        }
+
+        for ( const key in this.globals ) {
+            if ( !hasOwnProperty(this.globals, key) ) {
+                continue
+            }
+
+            globals[key] = this.globals[key](req)
+        }
+
+        return globals
+    }
+
+    /**
+     * Register a new factory that produces a global available in the templates by default.
+     * @param name
+     * @param factory
+     */
+    public registerGlobalFactory(name: string, factory: (req: Maybe<Request>) => any): this {
+        this.globals[name] = factory
+        return this
     }
 
     /**