Convert DataContext to ES2015 class

ValueFormatter.js

@@ -10,6 +10,7 @@ const { AsyncSeriesEventEmitter } = require('@themost/events');
 const { round } = require('@themost/query');
 const MD5 = require('crypto-js/md5');
 const { DataAttributeResolver } = require('./data-attribute-resolver');
+const { firstValueFrom } = require('rxjs');
 
 const testFieldRegex = /^\$\w+(\.\w+)*$/g;
 
@@ -166,15 +167,14 @@ class ValueDialect {
    * @param {string=} property 
    * @returns Promise<any>
    */
-  $user(property) {
+  async $user(property) {
     const selectAttribute = property || 'id';
-    let name = this.context.user && this.context.user.name;
-    if (Object.prototype.hasOwnProperty.call(this.context, 'interactiveUser') === true) {
-      name = this.context.interactiveUser && this.context.interactiveUser.name;
+    const source$ = this.context.interactiveUser ? this.context.interactiveUser$ : this.context.user$;
+    const user = await firstValueFrom(source$);
+    if (user == null) {
+      return null;
     }
-    return this.context.model('User').asQueryable().where((x, username) => {
-      return x.name === username && x.name != null && x.name != 'anonymous';
-    }, name).select(selectAttribute).value();
+    return getProperty(user, selectAttribute);
   }
   /**
    * A shorthand for $user method

data-context.d.ts

@@ -1,15 +1,22 @@
 // MOST Web Framework 2.0 Codename Blueshift BSD-3-Clause license Copyright (c) 2017-2022, THEMOST LP All rights reserved
+import { DataModel } from "data-model";
 import {DataAdapter, DataContext} from "./types";
-import { DataAdapterBase } from '@themost/common';
+import { ConfigurationBase, DataAdapterBase } from '@themost/common';
 
 export declare class DefaultDataContext extends DataContext {
+    model(name: any): DataModel;
+    getConfiguration(): ConfigurationBase;
+    finalize(callback?: (err?: Error) => void): void;
     constructor();
     readonly name: string;
     getDb(): DataAdapterBase;
     setDb(db: DataAdapterBase): void;
 }
 
 export declare class NamedDataContext extends DataContext {
+    model(name: any): DataModel;
+    getConfiguration(): ConfigurationBase;
+    finalize(callback?: (err?: Error) => void): void;
     constructor(name: string);
     readonly name: string;
     getName(): string