From 2c3e2c651df5979c0f7de642a7d5c5f8cf82af2b Mon Sep 17 00:00:00 2001
From: Ben Goldsworthy <b.r.goldsworthy@lancaster.ac.uk>
Date: Sat, 28 Nov 2020 19:36:19 +0000
Subject: [PATCH 1/2] Add database connection check

---
 src/app/app.module.ts            | 13 ++++++++++++-
 src/app/providers/api-service.ts |  7 +++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/app/app.module.ts b/src/app/app.module.ts
index 067c810..934d439 100644
--- a/src/app/app.module.ts
+++ b/src/app/app.module.ts
@@ -93,7 +93,18 @@ import { FilterPipeModule } from 'ngx-filter-pipe';
   bootstrap: [ AppComponent ]
 })
 export class AppModule {
-  constructor () {
+  constructor (
+    private api: ApiService,
+  ) {
+    this.api.checkDatabaseConnection().subscribe(
+      result => {
+      },
+      error => {
+        document.location = '#/500';
+        throw new Error('Server connection fail');
+      }
+    );
+
     if (environment.enableAnalytics) {
       (<any>window).ga('create', environment.analyticsKey, 'auto');
     }
diff --git a/src/app/providers/api-service.ts b/src/app/providers/api-service.ts
index 8307371..a468ee9 100644
--- a/src/app/providers/api-service.ts
+++ b/src/app/providers/api-service.ts
@@ -42,6 +42,13 @@ export class ApiService {
     localStorage.removeItem('sessionKey');
   }
 
+  public checkDatabaseConnection() {
+    return this.http.post<any>(
+      this.apiUrl,
+      null
+    );
+  }
+
   public register(data) {
     return this.http.post<any>(
       this.apiUrl + '/register',

From 4e5edece48ed6af4f72cb97154ccf51dd489520f Mon Sep 17 00:00:00 2001
From: Ben Goldsworthy <b.r.goldsworthy@lancaster.ac.uk>
Date: Sat, 28 Nov 2020 19:36:31 +0000
Subject: [PATCH 2/2] Correct HTTP500 error text

---
 src/app/pages/500.component.html | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/app/pages/500.component.html b/src/app/pages/500.component.html
index e09fae4..79ff5ec 100644
--- a/src/app/pages/500.component.html
+++ b/src/app/pages/500.component.html
@@ -5,7 +5,7 @@
         <div class="clearfix">
           <h1 class="float-left display-3 mr-4">500</h1>
           <h4 class="pt-3">Houston, we have a problem!</h4>
-          <p class="text-muted">The page you are looking for is temporarily unavailable.</p>
+          <p class="text-muted">Server connection unavailable.</p>
         </div>
         <span class="input-group-btn">
           <button class="btn btn-primary btn-lg" type="button"(click)="goBack()">Go Back</button>