add Subscriptions

README.md

@@ -54,7 +54,7 @@ npx tsc --init --rootDir src --outDir build \
 ```
 
 ```
-npm install --save-dev ts-node nodemon rimraf uuid @types/uuid
+npm install --save-dev ts-node nodemon rimraf uuid @types/uuid apollo-link-ws
 ```
 
 

backend/graphql.schema.json

@@ -7,7 +7,9 @@
     "mutationType": {
       "name": "Mutation"
     },
-    "subscriptionType": null,
+    "subscriptionType": {
+      "name": "Subscription"
+    },
     "types": [
       {
         "kind": "OBJECT",
@@ -547,6 +549,57 @@
         "enumValues": null,
         "possibleTypes": null
       },
+      {
+        "kind": "OBJECT",
+        "name": "Subscription",
+        "description": null,
+        "fields": [
+          {
+            "name": "pizzasChanged",
+            "description": null,
+            "args": [],
+            "type": {
+              "kind": "NON_NULL",
+              "name": null,
+              "ofType": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "Pizza",
+                  "ofType": null
+                }
+              }
+            },
+            "isDeprecated": false,
+            "deprecationReason": null
+          },
+          {
+            "name": "toppingsChanged",
+            "description": null,
+            "args": [],
+            "type": {
+              "kind": "NON_NULL",
+              "name": null,
+              "ofType": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "Topping",
+                  "ofType": null
+                }
+              }
+            },
+            "isDeprecated": false,
+            "deprecationReason": null
+          }
+        ],
+        "inputFields": null,
+        "interfaces": [],
+        "enumValues": null,
+        "possibleTypes": null
+      },
       {
         "kind": "OBJECT",
         "name": "__Schema",

backend/src/generated/graphql.ts

@@ -96,6 +96,12 @@ export type MutationUpdateToppingArgs = {
   updatedToppingDto: ChangeToppingDto;
 };
 
+export type Subscription = {
+  __typename?: 'Subscription';
+  pizzasChanged: Array<Maybe<Pizza>>;
+  toppingsChanged: Array<Maybe<Topping>>;
+};
+
 
 
 export type ResolverTypeWrapper<T> = Promise<T> | T;
@@ -183,6 +189,7 @@ export type ResolversTypes = {
   ChangePizzaDto: ChangePizzaDto;
   ChangeToppingDto: ChangeToppingDto;
   Mutation: ResolverTypeWrapper<{}>;
+  Subscription: ResolverTypeWrapper<{}>;
 };
 
 /** Mapping between all available schema types and the resolvers parents */
@@ -196,6 +203,7 @@ export type ResolversParentTypes = {
   ChangePizzaDto: ChangePizzaDto;
   ChangeToppingDto: ChangeToppingDto;
   Mutation: {};
+  Subscription: {};
 };
 
 export type PizzaResolvers<ContextType = any, ParentType extends ResolversParentTypes['Pizza'] = ResolversParentTypes['Pizza']> = {
@@ -227,11 +235,17 @@ export type MutationResolvers<ContextType = any, ParentType extends ResolversPar
   updateTopping?: Resolver<ResolversTypes['Topping'], ParentType, ContextType, RequireFields<MutationUpdateToppingArgs, 'toppingId' | 'updatedToppingDto'>>;
 };
 
+export type SubscriptionResolvers<ContextType = any, ParentType extends ResolversParentTypes['Subscription'] = ResolversParentTypes['Subscription']> = {
+  pizzasChanged?: SubscriptionResolver<Array<Maybe<ResolversTypes['Pizza']>>, "pizzasChanged", ParentType, ContextType>;
+  toppingsChanged?: SubscriptionResolver<Array<Maybe<ResolversTypes['Topping']>>, "toppingsChanged", ParentType, ContextType>;
+};
+
 export type Resolvers<ContextType = any> = {
   Pizza?: PizzaResolvers<ContextType>;
   Topping?: ToppingResolvers<ContextType>;
   Query?: QueryResolvers<ContextType>;
   Mutation?: MutationResolvers<ContextType>;
+  Subscription?: SubscriptionResolvers<ContextType>;
 };
 
 

backend/src/index.ts

@@ -1,11 +1,9 @@
-import { ApolloServer } from "apollo-server/dist";
+import { ApolloServer, PubSub } from "apollo-server/dist";
 import { Resolvers, ChangePizzaDto, ChangeToppingDto } from "./generated/graphql";
 import { pizzaSchema } from "./schema/pizza";
 import { PizzaResolver } from "./resolver/pizza-resolver";
 import { ToppingResolver } from "./resolver/topping-resolver";
 
-
-
 const resolvers: Resolvers = {
     Topping: {
         id: (root, args, context) => {
@@ -59,14 +57,25 @@ const resolvers: Resolvers = {
         updateTopping: (root, args, context) => {
             return ToppingResolver.update(args.toppingId, args.updatedToppingDto as ChangeToppingDto);
         },
+    },
+    Subscription: {
+        pizzasChanged: {
+            subscribe: () => PizzaResolver.pizzaEvent.asyncIterator(PizzaResolver.events.PIZZA_CHANGED)
+
+        },
+        toppingsChanged: {
+            subscribe: () => ToppingResolver.toppingEvent.asyncIterator(ToppingResolver.events.TOPPING_CHANGED)
+        },
     }
 }
 
 const server = new ApolloServer({
     typeDefs: pizzaSchema,
-    resolvers: resolvers as any
-});
+    resolvers: resolvers as any,
+}
+);
 
-server.listen().then(({ url }) => {
+server.listen().then(({ url, subscriptionsUrl }) => {
     console.log(`🚀 Server ready at ${url}`)
+    console.log(`🚀 Subscriptions ready at ${subscriptionsUrl}`);
 });

backend/src/resolver/pizza-resolver.ts

@@ -2,9 +2,15 @@ import { Topping, Pizza, ChangePizzaDto, Maybe } from "../generated/graphql";
 import { PizzaList } from "../data/pizza-list";
 import { v4 as uuidv4 } from 'uuid';
 import { ToppingResolver } from "./topping-resolver";
+import { PubSub } from "apollo-server";
 
 export class PizzaResolver {
 
+    static pizzaEvent = new PubSub();
+    static events = {
+        PIZZA_CHANGED: "pizzaChanged",
+    }    
+
     static getById = (id: string): Pizza => {
         return PizzaList.filter(pizza => pizza.id === id)[0];
     };
@@ -18,14 +24,21 @@ export class PizzaResolver {
     };
 
     static create = (pizzaCreateDto: ChangePizzaDto): Pizza => {
+        // Get Topping Objects by Ids
         const toppings: Topping[] = pizzaCreateDto.toppingIds
             .map<string>((toppingId) => toppingId as string)
             .map<Topping>((toppingId) => ToppingResolver.getById(toppingId));
+        // Init new Pizza Object
         const pizza: Pizza = {
             id: uuidv4(),
             name: pizzaCreateDto.name,
             toppings: toppings
         }
+        // Add Pizza to 'Database'
+        PizzaList.push(pizza);
+        PizzaResolver.pizzaEvent.publish(PizzaResolver.events.PIZZA_CHANGED, {
+            pizzasChanged: PizzaList
+        });
         console.log(`Create Pizza ...`, pizza)
         return pizza;
     };
@@ -42,7 +55,12 @@ export class PizzaResolver {
             .map<Topping>((toppingId: string) => ToppingResolver.getById(toppingId));
         pizza.name = pizzaUpdateDto.name;
         pizza.toppings = toppings;
+        const pizzaIndex = PizzaList.indexOf(pizza);
+        PizzaList[pizzaIndex] = pizza;
         console.log(`Update Pizza ...`, pizza)
+        PizzaResolver.pizzaEvent.publish(PizzaResolver.events.PIZZA_CHANGED, {
+            pizzasChanged: PizzaList
+        });
         return pizza;
     };
 

backend/src/resolver/topping-resolver.ts

@@ -2,7 +2,16 @@ import { Topping, ChangeToppingDto, } from "../generated/graphql";
 import { ToppingList } from "../data/topping-list";
 import { v4 as uuidv4 } from 'uuid';
 import { EEXIST } from "constants";
+import { PubSub } from "apollo-server";
+
+
 export class ToppingResolver {
+
+    static toppingEvent = new PubSub();
+    static events = {
+        TOPPING_CHANGED: "toppingChanged",
+    }
+
     static getById = (id: string): Topping => {
         return ToppingList.filter(topping => topping.id === id)[0];
     };
@@ -20,7 +29,11 @@ export class ToppingResolver {
             id: uuidv4(),
             name: toppingCreateDto.name,
         }
-        console.log(`Create Topping ...`, topping)
+        ToppingList.push(topping);
+        console.log(`Create Topping ...`, topping);
+        ToppingResolver.toppingEvent.publish(ToppingResolver.events.TOPPING_CHANGED, {
+            toppingsChanged: ToppingList
+        });
         return topping;
     };
 
@@ -32,7 +45,12 @@ export class ToppingResolver {
                 `No Topping found with id ${toppingId}`
             )
         }
-        topping.name = toppingUpdateDto.name; 
+        topping.name = toppingUpdateDto.name;
+        const toppingIndex = ToppingList.indexOf(topping);
+        ToppingList[toppingIndex] = topping;
+        ToppingResolver.toppingEvent.publish(ToppingResolver.events.TOPPING_CHANGED, {
+            toppingsChanged: ToppingList
+        });
         console.log(`Update Topping ...`, topping)
         return topping;
     };

backend/src/schema/pizza.ts

@@ -43,4 +43,9 @@ export const pizzaSchema = gql`
     createTopping(createToppingDto: ChangeToppingDto): Topping!
     updateTopping(toppingId: ID!, updatedToppingDto: ChangeToppingDto!): Topping!
   }
+
+  type Subscription {
+    pizzasChanged: [Pizza]!
+    toppingsChanged: [Topping]!
+  }
 `;

backend/tsconfig.json

@@ -7,7 +7,7 @@
     ] /* Specify library files to be included in the compilation. */,
     "allowJs": true /* Allow javascript files to be compiled. */,
     "outDir": "build" /* Redirect output structure to the directory. */,
-    "rootDir": "../srceal.js/assets/src" /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */,
+    "rootDir": "./src" /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */,
     "strict": true /* Enable all strict type-checking options. */,
     "skipLibCheck": true,
     "noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,

frontend/package-lock.json

@@ -3281,6 +3281,22 @@
         }
       }
     },
+    "apollo-link-ws": {
+      "version": "1.0.20",
+      "resolved": "https://registry.npmjs.org/apollo-link-ws/-/apollo-link-ws-1.0.20.tgz",
+      "integrity": "sha512-mjSFPlQxmoLArpHBeUb2Xj+2HDYeTaJqFGOqQ+I8NVJxgL9lJe84PDWcPah/yMLv3rB7QgBDSuZ0xoRFBPlySw==",
+      "requires": {
+        "apollo-link": "^1.2.14",
+        "tslib": "^1.9.3"
+      },
+      "dependencies": {
+        "tslib": {
+          "version": "1.13.0",
+          "resolved": "https://registry.npmjs.org/tslib/-/tslib-1.13.0.tgz",
+          "integrity": "sha512-i/6DQjL8Xf3be4K/E6Wgpekn5Qasl1usyw++dAA35Ue5orEn65VIxOA+YvNNl9HV3qv70T7CNwjODHZrLwvd1Q=="
+        }
+      }
+    },
     "apollo-utilities": {
       "version": "1.3.4",
       "resolved": "https://registry.npmjs.org/apollo-utilities/-/apollo-utilities-1.3.4.tgz",
@@ -3486,8 +3502,7 @@
     "async-limiter": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/async-limiter/-/async-limiter-1.0.1.tgz",
-      "integrity": "sha512-csOlWGAcRFJaI6m+F2WKdnMKr4HhdhFVBk0H/QbJFMCr+uO2kwohwXQPxw/9OCxp05r5ghVBFSyioixx3gfkNQ==",
-      "dev": true
+      "integrity": "sha512-csOlWGAcRFJaI6m+F2WKdnMKr4HhdhFVBk0H/QbJFMCr+uO2kwohwXQPxw/9OCxp05r5ghVBFSyioixx3gfkNQ=="
     },
     "asynckit": {
       "version": "0.4.0",
@@ -3648,8 +3663,7 @@
     "backo2": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/backo2/-/backo2-1.0.2.tgz",
-      "integrity": "sha1-MasayLEpNjRj41s+u2n038+6eUc=",
-      "dev": true
+      "integrity": "sha1-MasayLEpNjRj41s+u2n038+6eUc="
     },
     "balanced-match": {
       "version": "1.0.0",
@@ -8240,8 +8254,7 @@
     "iterall": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/iterall/-/iterall-1.3.0.tgz",
-      "integrity": "sha512-QZ9qOMdF+QLHxy1QIpUHUU1D5pS2CG2P69LF6L6CPjPYA/XMOmKV3PZpawHoAjHNyB0swdVTRxdYT4tbBbxqwg==",
-      "dev": true
+      "integrity": "sha512-QZ9qOMdF+QLHxy1QIpUHUU1D5pS2CG2P69LF6L6CPjPYA/XMOmKV3PZpawHoAjHNyB0swdVTRxdYT4tbBbxqwg=="
     },
     "jasmine": {
       "version": "2.8.0",
@@ -14214,7 +14227,6 @@
       "version": "0.9.17",
       "resolved": "https://registry.npmjs.org/subscriptions-transport-ws/-/subscriptions-transport-ws-0.9.17.tgz",
       "integrity": "sha512-hNHi2N80PBz4T0V0QhnnsMGvG3XDFDS9mS6BhZ3R12T6EBywC8d/uJscsga0cVO4DKtXCkCRrWm2sOYrbOdhEA==",
-      "dev": true,
       "requires": {
         "backo2": "^1.0.2",
         "eventemitter3": "^3.1.0",
@@ -14226,14 +14238,12 @@
         "eventemitter3": {
           "version": "3.1.2",
           "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-3.1.2.tgz",
-          "integrity": "sha512-tvtQIeLVHjDkJYnzf2dgVMxfuSGJeM/7UCG17TT4EumTfNtF+0nebF/4zWOIkCreAbtNqhGEboB6BWrwqNaw4Q==",
-          "dev": true
+          "integrity": "sha512-tvtQIeLVHjDkJYnzf2dgVMxfuSGJeM/7UCG17TT4EumTfNtF+0nebF/4zWOIkCreAbtNqhGEboB6BWrwqNaw4Q=="
         },
         "ws": {
           "version": "5.2.2",
           "resolved": "https://registry.npmjs.org/ws/-/ws-5.2.2.tgz",
           "integrity": "sha512-jaHFD6PFv6UgoIVda6qZllptQsMlDEJkTQcybzzXDYM1XO9Y8em691FGMPmM46WGyLU4z9KMgQN+qrux/nhlHA==",
-          "dev": true,
           "requires": {
             "async-limiter": "~1.0.0"
           }

frontend/package.json

@@ -27,9 +27,11 @@
     "apollo-cache-inmemory": "^1.6.0",
     "apollo-client": "^2.6.0",
     "apollo-link": "^1.2.11",
+    "apollo-link-ws": "^1.0.20",
     "graphql": "^15.3.0",
     "graphql-tag": "^2.10.0",
     "rxjs": "~6.5.5",
+    "subscriptions-transport-ws": "^0.9.17",
     "tslib": "^2.0.0",
     "zone.js": "~0.10.3"
   },

frontend/src/app/app.component.html

@@ -15,6 +15,12 @@
     <mat-sidenav-content>
       <app-pizza-list></app-pizza-list>
       <app-pizza-list-with-topping></app-pizza-list-with-topping>
+
+      <div class=row>
+        <app-pizza-create class="col-6"></app-pizza-create>
+        <app-topping-create class="col-6"></app-topping-create>
+      </div>
+
       <mat-toolbar class="footer"></mat-toolbar>
     </mat-sidenav-content>
   </mat-sidenav-container>

frontend/src/app/app.module.ts

@@ -1,32 +1,46 @@
-import { BrowserModule } from '@angular/platform-browser';
+import { CommonModule } from '@angular/common';
+import { HttpClientModule } from '@angular/common/http';
 import { NgModule } from '@angular/core';
+import { ReactiveFormsModule } from '@angular/forms';
+import { MatButtonModule } from '@angular/material/button';
 import { MatCardModule } from '@angular/material/card';
 import { MatCheckboxModule } from '@angular/material/checkbox';
+import { MatFormFieldModule } from '@angular/material/form-field';
 import { MatIconModule } from '@angular/material/icon';
 import { MatInputModule } from '@angular/material/input';
 import { MatListModule } from '@angular/material/list';
 import { MatMenuModule } from '@angular/material/menu';
+import { MatSelectModule } from '@angular/material/select';
 import { MatSidenavModule } from '@angular/material/sidenav';
 import { MatTableModule } from '@angular/material/table';
 import { MatTabsModule } from '@angular/material/tabs';
 import { MatToolbarModule } from '@angular/material/toolbar';
-import { MatButtonModule } from '@angular/material/button';
-import { AppComponent } from './app.component';
-import { GraphQLModule } from '../graphql.module';
-import { HttpClientModule } from '@angular/common/http';
+import { MatSnackBarModule } from '@angular/material/snack-bar';
+import { BrowserModule } from '@angular/platform-browser';
 import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
-import { PizzaListComponent } from './pizza-list/pizza-list.component';
+import { Apollo } from 'apollo-angular';
+import { HttpLink } from 'apollo-angular-link-http';
+import { GraphQLModule } from '../graphql.module';
+import { AppComponent } from './app.component';
+import { PizzaCreateComponent } from './pizza-create/pizza-create.component';
 import { PizzaListWithToppingComponent } from './pizza-list-with-topping/pizza-list-with-topping.component';
-import { CommonModule } from '@angular/common';
-import { FormsModule } from '@angular/forms';
+import { PizzaListComponent } from './pizza-list/pizza-list.component';
+import { ToppingCreateComponent } from './topping-create/topping-create.component';
+
+
 
 @NgModule({
   declarations: [
     AppComponent,
     PizzaListComponent,
     PizzaListWithToppingComponent,
+    PizzaCreateComponent,
+    ToppingCreateComponent,
   ],
   imports: [
+    MatSnackBarModule,
+    MatSelectModule,
+    MatFormFieldModule,
     MatCheckboxModule,
     MatCardModule,
     MatInputModule,
@@ -41,7 +55,7 @@ import { FormsModule } from '@angular/forms';
     BrowserModule,
     HttpClientModule,
     CommonModule,
-    FormsModule,
+    ReactiveFormsModule,
     GraphQLModule,
     BrowserModule,
     GraphQLModule,
@@ -51,4 +65,40 @@ import { FormsModule } from '@angular/forms';
   providers: [],
   bootstrap: [AppComponent]
 })
-export class AppModule { }
+export class AppModule {
+  constructor(
+    apollo: Apollo,
+    httpLink: HttpLink
+  ) {
+    // // Create an http link:
+    // const http = httpLink.create({
+    //   uri: 'http://localhost:4000'
+    // });
+
+    // // Create a WebSocket link:
+    // const ws = new WebSocketLink({
+    //   uri: `ws://localhost:4000/`,
+    //   options: {
+    //     reconnect: true
+    //   }
+    // });
+
+    // // using the ability to split links, you can send data to each link
+    // // depending on what kind of operation is being sent
+    // const link = split(
+    //   // split based on operation type
+    //   ({ query }) => {
+    //     const { kind } = getMainDefinition(query);
+    //     return kind === 'OperationDefinition';
+    //   },
+    //   ws,
+    //   http,
+    // );
+
+    // apollo.create({
+    //   link,
+    //   cache: null
+    // });
+  }
+
+}

frontend/src/app/pizza-create/pizza-create-topping-subscription.graphql

@@ -0,0 +1,6 @@
+subscription ToppingChanged {
+  toppingsChanged {
+    id
+    name
+  }
+}

frontend/src/app/pizza-create/pizza-create-toppings.graphql

@@ -0,0 +1,6 @@
+query ListToppingsForPizzaCreate {
+  listTopping {
+    id
+    name
+  }
+}

frontend/src/app/pizza-create/pizza-create.component.html

@@ -0,0 +1,36 @@
+<div class="container">
+  <form [formGroup]="pizzaCreateForm" (ngSubmit)="create()" class="form">
+    <h1>Create Pizza</h1>
+    <mat-form-field class="form-element">
+      <mat-label>
+        Name
+      </mat-label>
+      <input matInput type="text" formControlName="pizzaName" />
+    </mat-form-field>
+
+    <mat-form-field appearance="fill">
+      <mat-label>Toppings</mat-label>
+      <mat-select
+        name="selectedToppings"
+        [formControl]="pizzaToppings"
+        multiple
+      >
+        <mat-select-trigger>
+          {{ pizzaToppings.value ? pizzaToppings.value[0]?.name : "" }}
+          <span
+            *ngIf="pizzaToppings.value?.length > 1"
+            class="example-additional-selection"
+          >
+            (+{{ pizzaToppings.value?.length - 1 }}
+            {{ pizzaToppings.value?.length === 2 ? "other" : "others" }})
+          </span>
+        </mat-select-trigger>
+        <mat-option *ngFor="let topping of toppings" [value]="topping">{{
+          topping.name
+        }}</mat-option>
+      </mat-select>
+    </mat-form-field>
+    <br>
+    <button mat-button type="submit">Submit</button>
+  </form>
+</div>

frontend/src/app/pizza-create/pizza-create.component.spec.ts

@@ -0,0 +1,25 @@
+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+
+import { PizzaCreateComponent } from './pizza-create.component';
+
+describe('PizzaCreateComponent', () => {
+  let component: PizzaCreateComponent;
+  let fixture: ComponentFixture<PizzaCreateComponent>;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      declarations: [ PizzaCreateComponent ]
+    })
+    .compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(PizzaCreateComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});

frontend/src/app/pizza-create/pizza-create.component.ts

@@ -0,0 +1,69 @@
+import { Component, OnInit } from '@angular/core';
+import { FormControl, FormGroup } from '@angular/forms';
+import { map } from 'rxjs/operators';
+import { ChangePizzaDto, CreatePizzaGQL, ListToppingsForPizzaCreateGQL, Topping, ToppingChangedGQL } from 'src/generated/graphql';
+import { MatSnackBar } from '@angular/material/snack-bar';
+
+@Component({
+  selector: 'app-pizza-create',
+  templateUrl: './pizza-create.component.html',
+  styleUrls: ['./pizza-create.component.scss']
+})
+export class PizzaCreateComponent implements OnInit {
+
+
+  pizzaName = new FormControl('');
+  pizzaToppings = new FormControl([]);
+  pizzaCreateForm = new FormGroup({
+    pizzaName: this.pizzaName,
+    pizzaToppings: this.pizzaToppings,
+  });
+
+  toppings: Topping[];
+
+  create(): void {
+    if (!this.pizzaCreateForm.valid) {
+      return;
+    }
+    const createPizzaDto: ChangePizzaDto = {
+      name: this.pizzaName.value,
+      toppingIds: this.pizzaToppings.value.map((topping: Topping) => topping.id)
+    };
+    this.createPizza
+      .mutate({ createPizzaDto })
+      .subscribe((res) => {
+        this.snackBar.open(
+          `created Pizza ${res.data.createPizza.name}`,
+          'ok',
+          {
+            duration: 1000
+          }
+        );
+      });
+    this.pizzaName.setValue(null);
+    this.pizzaToppings.setValue([]);
+  }
+
+  ngOnInit(): void {
+  }
+
+  constructor(
+    listToppings: ListToppingsForPizzaCreateGQL,
+    protected createPizza: CreatePizzaGQL,
+    toppingChanged: ToppingChangedGQL,
+    private snackBar: MatSnackBar
+  ) {
+    listToppings
+      .watch()
+      .valueChanges
+      .pipe(map(result => result.data.listTopping as Topping[]))
+      .subscribe(toppings => this.toppings = toppings);
+    toppingChanged
+      .subscribe()
+      .pipe(map(event => event.data.toppingsChanged as Topping[]))
+      .subscribe(toppings => this.toppings = toppings);
+  }
+
+
+
+}

frontend/src/app/pizza-create/pizza-create.graphql

@@ -0,0 +1,5 @@
+mutation CreatePizza($createPizzaDto: ChangePizzaDto) {
+  createPizza (createPizzaDto: $createPizzaDto) {
+    name
+  }
+}

frontend/src/app/pizza-list-with-topping/pizza-list-with-topping-subscription.graphql

@@ -0,0 +1,9 @@
+subscription PizzaWithToppingChanged {
+  pizzasChanged {
+    id,
+    name
+    toppings {
+      name
+    }
+  }
+}

frontend/src/app/pizza-list-with-topping/pizza-list-with-topping.component.html

@@ -1,34 +1,36 @@
-<mat-toolbar>
-  <mat-toolbar-row>
-    <h1>Pizzas With topping</h1>
-  </mat-toolbar-row>
-</mat-toolbar>
+<div class="container">
+  <mat-toolbar>
+    <mat-toolbar-row>
+      <h1>Pizzas With topping</h1>
+    </mat-toolbar-row>
+  </mat-toolbar>
 
-<table mat-table [dataSource]="pizzas">
-  <ng-container matColumnDef="id">
-    <th class="id" mat-header-cell *matHeaderCellDef>ID</th>
-    <td class="id" mat-cell *matCellDef="let pizza; let i = index">
-      {{ pizza.id }}
-    </td>
-  </ng-container>
+  <table mat-table [dataSource]="pizzas">
+    <ng-container matColumnDef="id">
+      <th class="id" mat-header-cell *matHeaderCellDef>ID</th>
+      <td class="id" mat-cell *matCellDef="let pizza; let i = index">
+        {{ pizza.id }}
+      </td>
+    </ng-container>
 
-  <ng-container matColumnDef="name">
-    <th class="name" mat-header-cell *matHeaderCellDef>Name</th>
-    <td class="name" mat-cell *matCellDef="let pizza; let i = index">
-      {{ pizza.name }}
-    </td>
-  </ng-container>
+    <ng-container matColumnDef="name">
+      <th class="name" mat-header-cell *matHeaderCellDef>Name</th>
+      <td class="name" mat-cell *matCellDef="let pizza; let i = index">
+        {{ pizza.name }}
+      </td>
+    </ng-container>
 
-  <ng-container matColumnDef="toppings">
-    <th class="toppings" mat-header-cell *matHeaderCellDef>Name</th>
-    <td class="toppings" mat-cell *matCellDef="let pizza; let i = index">
-      {{ getToppingListString(pizza.toppings) }}
-    </td>
-  </ng-container>
+    <ng-container matColumnDef="toppings">
+      <th class="toppings" mat-header-cell *matHeaderCellDef>Name</th>
+      <td class="toppings" mat-cell *matCellDef="let pizza; let i = index">
+        {{ getToppingListString(pizza.toppings) }}
+      </td>
+    </ng-container>
 
-  <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
-  <tr mat-row *matRowDef="let row; columns: displayedColumns"></tr>
-</table>
-<ng-template #nopizzaSelected>
-  no pizza selected, please select a pizza to see events!
-</ng-template>
+    <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
+    <tr mat-row *matRowDef="let row; columns: displayedColumns"></tr>
+  </table>
+  <ng-template #nopizzaSelected>
+    no pizza selected, please select a pizza to see events!
+  </ng-template>
+</div>

frontend/src/app/pizza-list-with-topping/pizza-list-with-topping.component.ts

@@ -1,7 +1,7 @@
 import { Component, OnInit } from '@angular/core';
-import { Pizza, ListPizzaGQL, ListPizzaWithToppingGQL, Topping } from 'src/generated/graphql';
-import { Observable } from 'rxjs';
+import { Subject } from 'rxjs';
 import { map } from 'rxjs/operators';
+import { ListPizzaWithToppingGQL, Pizza, PizzaWithToppingChangedGQL, Topping } from 'src/generated/graphql';
 
 
 @Component({
@@ -18,15 +18,17 @@ export class PizzaListWithToppingComponent implements OnInit {
     'toppings'
   ];
 
-  pizzas: Observable<Pizza[]>;
+  pizzas = new Subject<Pizza[]>();
 
-
-
-  constructor(listPizzaWithToppings: ListPizzaWithToppingGQL) {
-    this.pizzas = listPizzaWithToppings
+  constructor(listPizzaWithToppings: ListPizzaWithToppingGQL, pizzaChanged: PizzaWithToppingChangedGQL) {
+    listPizzaWithToppings
       .watch()
       .valueChanges
-      .pipe(map(result => result.data.listPizza as Pizza[]));
+      .pipe(map(result => result.data.listPizza as Pizza[]))
+      .subscribe((pizzas => this.pizzas.next(pizzas)));
+    pizzaChanged.subscribe().pipe(map(event => event.data.pizzasChanged as Pizza[]))
+      .subscribe((pizzas => this.pizzas.next(pizzas)));
+
   }
 
   ngOnInit(): void {

frontend/src/app/pizza-list/pizza-list-subscription.graphql

@@ -0,0 +1,6 @@
+subscription PizzaChanged {
+  pizzasChanged {
+    id
+    name
+  }
+}

frontend/src/app/pizza-list/pizza-list.component.html

@@ -1,27 +1,29 @@
-<mat-toolbar>
-  <mat-toolbar-row>
-    <h1>Pizza</h1>
-  </mat-toolbar-row>
-</mat-toolbar>
+<div class="container">
+  <mat-toolbar>
+    <mat-toolbar-row>
+      <h1>Pizza</h1>
+    </mat-toolbar-row>
+  </mat-toolbar>
 
-<table mat-table [dataSource]="pizzas">
-  <ng-container matColumnDef="id">
-    <th class="id" mat-header-cell *matHeaderCellDef>ID</th>
-    <td class="id" mat-cell *matCellDef="let pizza; let i = index">
-      {{ pizza.id }}
-    </td>
-  </ng-container>
+  <table mat-table [dataSource]="pizzas">
+    <ng-container matColumnDef="id">
+      <th class="id" mat-header-cell *matHeaderCellDef>ID</th>
+      <td class="id" mat-cell *matCellDef="let pizza; let i = index">
+        {{ pizza.id }}
+      </td>
+    </ng-container>
 
-  <ng-container matColumnDef="name">
-    <th class="name" mat-header-cell *matHeaderCellDef>Name</th>
-    <td class="name" mat-cell *matCellDef="let pizza; let i = index">
-      {{ pizza.name }}
-    </td>
-  </ng-container>
+    <ng-container matColumnDef="name">
+      <th class="name" mat-header-cell *matHeaderCellDef>Name</th>
+      <td class="name" mat-cell *matCellDef="let pizza; let i = index">
+        {{ pizza.name }}
+      </td>
+    </ng-container>
 
-  <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
-  <tr mat-row *matRowDef="let row; columns: displayedColumns"></tr>
-</table>
-<ng-template #nopizzaSelected>
-  no pizza selected, please select a pizza to see events!
-</ng-template>
+    <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
+    <tr mat-row *matRowDef="let row; columns: displayedColumns"></tr>
+  </table>
+  <ng-template #nopizzaSelected>
+    no pizza selected, please select a pizza to see events!
+  </ng-template>
+</div>

frontend/src/app/pizza-list/pizza-list.component.ts

@@ -1,6 +1,6 @@
-import { Component, OnInit } from '@angular/core';
-import { Pizza, ListPizzaGQL } from 'src/generated/graphql';
-import { Observable } from 'rxjs';
+import { Component, OnInit, DebugElement } from '@angular/core';
+import { Pizza, ListPizzaGQL, PizzaChangedGQL } from 'src/generated/graphql';
+import { Observable, race, combineLatest, concat, Subject } from 'rxjs';
 import { map } from 'rxjs/operators';
 
 
@@ -17,13 +17,17 @@ export class PizzaListComponent implements OnInit {
     'name',
   ];
 
-  pizzas: Observable<Pizza[]>;
+  pizzas = new Subject<Pizza[]>();
 
-  constructor(listPizza: ListPizzaGQL) {
-    this.pizzas = listPizza
-    .watch()
-    .valueChanges
-    .pipe(map(result => result.data.listPizza as Pizza[]));
+  constructor(listPizza: ListPizzaGQL, pizzaChanged: PizzaChangedGQL) {
+
+    listPizza
+      .watch()
+      .valueChanges
+      .pipe(map(result => result.data.listPizza as Pizza[]))
+      .subscribe((pizzas => this.pizzas.next(pizzas)));
+    pizzaChanged.subscribe().pipe(map(event => event.data.pizzasChanged as Pizza[]))
+      .subscribe((pizzas => this.pizzas.next(pizzas)));
   }
 
   ngOnInit(): void {

frontend/src/app/topping-create/topping-create.component.html

@@ -0,0 +1,13 @@
+<div class="container">
+  <form [formGroup]="toppingCreateForm" (ngSubmit)="create()" class="form">
+    <h1>Create Topping</h1>
+    <mat-form-field class="form-element">
+      <mat-label>
+        Name
+      </mat-label>
+      <input matInput type="text" formControlName="toppingName" />
+    </mat-form-field>
+    <br>
+    <button mat-button type="submit">Submit</button>
+  </form>
+</div>

frontend/src/app/topping-create/topping-create.component.spec.ts

@@ -0,0 +1,25 @@
+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+
+import { ToppingCreateComponent } from './topping-create.component';
+
+describe('ToppingCreateComponent', () => {
+  let component: ToppingCreateComponent;
+  let fixture: ComponentFixture<ToppingCreateComponent>;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      declarations: [ ToppingCreateComponent ]
+    })
+    .compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(ToppingCreateComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});

frontend/src/app/topping-create/topping-create.component.ts

@@ -0,0 +1,49 @@
+import { Component, OnInit } from '@angular/core';
+import { FormControl, FormGroup } from '@angular/forms';
+import { ChangeToppingDto, CreateToppingGQL } from 'src/generated/graphql';
+import { MatSnackBar } from '@angular/material/snack-bar';
+
+@Component({
+  selector: 'app-topping-create',
+  templateUrl: './topping-create.component.html',
+  styleUrls: ['./topping-create.component.scss']
+})
+export class ToppingCreateComponent implements OnInit {
+
+  toppingName = new FormControl('');
+  toppingCreateForm = new FormGroup({
+    toppingName: this.toppingName,
+  });
+
+
+  create(): void {
+    if (!this.toppingCreateForm.valid) {
+      return;
+    }
+    const createToppingDto: ChangeToppingDto = {
+      name: this.toppingName.value,
+    };
+    this.createToping
+      .mutate({ createToppingDto })
+      .subscribe((res) => {
+        this.snackBar.open(
+          `created Topping ${res.data.createTopping.name}`,
+          'ok',
+          {
+            duration: 1000
+          }
+        );
+      });
+    this.toppingName.setValue(null);
+  }
+
+  ngOnInit(): void {
+  }
+
+  constructor(
+    protected createToping: CreateToppingGQL,
+    private snackBar: MatSnackBar
+  ) {
+  }
+
+}

frontend/src/app/topping-create/topping-create.graphql

@@ -0,0 +1,5 @@
+mutation CreateTopping($createToppingDto: ChangeToppingDto) {
+  createTopping (createToppingDto: $createToppingDto) {
+    name
+  }
+}

frontend/src/generated/graphql.ts

@@ -59,12 +59,107 @@ export type QueryGetToppingByNameArgs = {
   toppingName: Scalars['ID'];
 };
 
+export type ChangePizzaDto = {
+  name: Scalars['String'];
+  toppingIds: Array<Maybe<Scalars['ID']>>;
+};
+
+export type ChangeToppingDto = {
+  name: Scalars['String'];
+};
+
+export type Mutation = {
+  __typename?: 'Mutation';
+  createPizza: Pizza;
+  updatePizza: Pizza;
+  createTopping: Topping;
+  updateTopping: Topping;
+};
+
+
+export type MutationCreatePizzaArgs = {
+  createPizzaDto?: Maybe<ChangePizzaDto>;
+};
+
+
+export type MutationUpdatePizzaArgs = {
+  pizzaId: Scalars['ID'];
+  updatedPizzaDto: ChangePizzaDto;
+};
+
+
+export type MutationCreateToppingArgs = {
+  createToppingDto?: Maybe<ChangeToppingDto>;
+};
+
+
+export type MutationUpdateToppingArgs = {
+  toppingId: Scalars['ID'];
+  updatedToppingDto: ChangeToppingDto;
+};
+
+export type Subscription = {
+  __typename?: 'Subscription';
+  pizzasChanged: Array<Maybe<Pizza>>;
+  toppingsChanged: Array<Maybe<Topping>>;
+};
+
 export enum CacheControlScope {
   Public = 'PUBLIC',
   Private = 'PRIVATE'
 }
 
 
+export type ToppingChangedSubscriptionVariables = Exact<{ [key: string]: never; }>;
+
+
+export type ToppingChangedSubscription = (
+  { __typename?: 'Subscription' }
+  & { toppingsChanged: Array<Maybe<(
+    { __typename?: 'Topping' }
+    & Pick<Topping, 'id' | 'name'>
+  )>> }
+);
+
+export type ListToppingsForPizzaCreateQueryVariables = Exact<{ [key: string]: never; }>;
+
+
+export type ListToppingsForPizzaCreateQuery = (
+  { __typename?: 'Query' }
+  & { listTopping: Array<Maybe<(
+    { __typename?: 'Topping' }
+    & Pick<Topping, 'id' | 'name'>
+  )>> }
+);
+
+export type CreatePizzaMutationVariables = Exact<{
+  createPizzaDto?: Maybe<ChangePizzaDto>;
+}>;
+
+
+export type CreatePizzaMutation = (
+  { __typename?: 'Mutation' }
+  & { createPizza: (
+    { __typename?: 'Pizza' }
+    & Pick<Pizza, 'name'>
+  ) }
+);
+
+export type PizzaWithToppingChangedSubscriptionVariables = Exact<{ [key: string]: never; }>;
+
+
+export type PizzaWithToppingChangedSubscription = (
+  { __typename?: 'Subscription' }
+  & { pizzasChanged: Array<Maybe<(
+    { __typename?: 'Pizza' }
+    & Pick<Pizza, 'id' | 'name'>
+    & { toppings: Array<(
+      { __typename?: 'Topping' }
+      & Pick<Topping, 'name'>
+    )> }
+  )>> }
+);
+
 export type ListPizzaWithToppingQueryVariables = Exact<{ [key: string]: never; }>;
 
 
@@ -80,6 +175,17 @@ export type ListPizzaWithToppingQuery = (
   )>> }
 );
 
+export type PizzaChangedSubscriptionVariables = Exact<{ [key: string]: never; }>;
+
+
+export type PizzaChangedSubscription = (
+  { __typename?: 'Subscription' }
+  & { pizzasChanged: Array<Maybe<(
+    { __typename?: 'Pizza' }
+    & Pick<Pizza, 'id' | 'name'>
+  )>> }
+);
+
 export type ListPizzaQueryVariables = Exact<{ [key: string]: never; }>;
 
 
@@ -91,6 +197,85 @@ export type ListPizzaQuery = (
   )>> }
 );
 
+export type CreateToppingMutationVariables = Exact<{
+  createToppingDto?: Maybe<ChangeToppingDto>;
+}>;
+
+
+export type CreateToppingMutation = (
+  { __typename?: 'Mutation' }
+  & { createTopping: (
+    { __typename?: 'Topping' }
+    & Pick<Topping, 'name'>
+  ) }
+);
+
+export const ToppingChangedDocument = gql`
+    subscription ToppingChanged {
+  toppingsChanged {
+    id
+    name
+  }
+}
+    `;
+
+  @Injectable({
+    providedIn: 'root'
+  })
+  export class ToppingChangedGQL extends Apollo.Subscription<ToppingChangedSubscription, ToppingChangedSubscriptionVariables> {
+    document = ToppingChangedDocument;
+    
+  }
+export const ListToppingsForPizzaCreateDocument = gql`
+    query ListToppingsForPizzaCreate {
+  listTopping {
+    id
+    name
+  }
+}
+    `;
+
+  @Injectable({
+    providedIn: 'root'
+  })
+  export class ListToppingsForPizzaCreateGQL extends Apollo.Query<ListToppingsForPizzaCreateQuery, ListToppingsForPizzaCreateQueryVariables> {
+    document = ListToppingsForPizzaCreateDocument;
+    
+  }
+export const CreatePizzaDocument = gql`
+    mutation CreatePizza($createPizzaDto: ChangePizzaDto) {
+  createPizza(createPizzaDto: $createPizzaDto) {
+    name
+  }
+}
+    `;
+
+  @Injectable({
+    providedIn: 'root'
+  })
+  export class CreatePizzaGQL extends Apollo.Mutation<CreatePizzaMutation, CreatePizzaMutationVariables> {
+    document = CreatePizzaDocument;
+    
+  }
+export const PizzaWithToppingChangedDocument = gql`
+    subscription PizzaWithToppingChanged {
+  pizzasChanged {
+    id
+    name
+    toppings {
+      name
+    }
+  }
+}
+    `;
+
+  @Injectable({
+    providedIn: 'root'
+  })
+  export class PizzaWithToppingChangedGQL extends Apollo.Subscription<PizzaWithToppingChangedSubscription, PizzaWithToppingChangedSubscriptionVariables> {
+    document = PizzaWithToppingChangedDocument;
+    
+  }
 export const ListPizzaWithToppingDocument = gql`
     query ListPizzaWithTopping {
   listPizza {
@@ -109,6 +294,22 @@ export const ListPizzaWithToppingDocument = gql`
   export class ListPizzaWithToppingGQL extends Apollo.Query<ListPizzaWithToppingQuery, ListPizzaWithToppingQueryVariables> {
     document = ListPizzaWithToppingDocument;
     
+  }
+export const PizzaChangedDocument = gql`
+    subscription PizzaChanged {
+  pizzasChanged {
+    id
+    name
+  }
+}
+    `;
+
+  @Injectable({
+    providedIn: 'root'
+  })
+  export class PizzaChangedGQL extends Apollo.Subscription<PizzaChangedSubscription, PizzaChangedSubscriptionVariables> {
+    document = PizzaChangedDocument;
+    
   }
 export const ListPizzaDocument = gql`
     query ListPizza {
@@ -125,4 +326,19 @@ export const ListPizzaDocument = gql`
   export class ListPizzaGQL extends Apollo.Query<ListPizzaQuery, ListPizzaQueryVariables> {
     document = ListPizzaDocument;
     
+  }
+export const CreateToppingDocument = gql`
+    mutation CreateTopping($createToppingDto: ChangeToppingDto) {
+  createTopping(createToppingDto: $createToppingDto) {
+    name
+  }
+}
+    `;
+
+  @Injectable({
+    providedIn: 'root'
+  })
+  export class CreateToppingGQL extends Apollo.Mutation<CreateToppingMutation, CreateToppingMutationVariables> {
+    document = CreateToppingDocument;
+    
   }

frontend/src/graphql.module.ts

@@ -1,13 +1,43 @@
-import {NgModule} from '@angular/core';
-import {ApolloModule, APOLLO_OPTIONS} from 'apollo-angular';
-import {HttpLinkModule, HttpLink} from 'apollo-angular-link-http';
-import {InMemoryCache} from 'apollo-cache-inmemory';
+import { NgModule } from '@angular/core';
+import { ApolloModule, APOLLO_OPTIONS, Apollo } from 'apollo-angular';
+import { HttpLink, HttpLinkModule } from 'apollo-angular-link-http';
+import { InMemoryCache } from 'apollo-cache-inmemory';
+import { WebSocketLink } from 'apollo-link-ws';
+import { split } from 'apollo-link';
+import { getMainDefinition } from 'apollo-utilities';
+import { OperationDefinitionNode } from 'graphql';
+
 
 const uri = 'http://localhost:4000'; // <-- add the URL of the GraphQL server here
-export function createApollo(httpLink: HttpLink) {
+const wsUri = 'ws://localhost:4000/graphql'; // <-- add the URL of the GraphQL server here
+export function createApollo(
+  httpLink: HttpLink
+) {
+
+  const http = httpLink.create({
+    uri
+  });
+
+  const ws = new WebSocketLink({
+    uri: wsUri,
+    options: {
+      reconnect: true,
+    },
+  });
+  const link = split(
+    // split based on operation type
+    ({ query }) => {
+      const { kind, operation } = getMainDefinition(query) as OperationDefinitionNode;
+      return kind === 'OperationDefinition' && operation === 'subscription';
+    },
+    ws,
+    http,
+  );
+
   return {
-    link: httpLink.create({uri}),
+    link,
     cache: new InMemoryCache(),
+
   };
 }
 
@@ -21,4 +51,4 @@ export function createApollo(httpLink: HttpLink) {
     },
   ],
 })
-export class GraphQLModule {}
+export class GraphQLModule { }

frontend/src/styles.scss

@@ -318,3 +318,19 @@ h1.main-app-name {
 table {
   width: 100%;
 }
+
+
+.container {
+  padding: 10px;
+}
+
+.form {
+  min-width: 150px;
+  max-width: 500px;
+  width: 100%;
+}
+
+.form-element {
+  padding: 5px 0px 25px 2px;
+  width: 100%;
+}

presentation/index.html

@@ -272,7 +272,8 @@
             </code>
             </pre>
           </section>
-
+        </section>
+        <section>
           <section>
             <img
               src="/assets/apollo-logo.png"