From 8bd61e52b76ec8c64a7de894fb165e303db8a532 Mon Sep 17 00:00:00 2001
From: Alexis Hernandez <alexis22229@gmail.com>
Date: Sun, 11 Mar 2018 12:27:44 -0600
Subject: [PATCH] web-ui: Add ErrorService

---
 web-ui/src/app/app.component.ts          |  1 +
 web-ui/src/app/app.module.ts             |  2 +
 web-ui/src/app/services/error.service.ts | 92 ++++++++++++++++++++++++
 3 files changed, 95 insertions(+)
 create mode 100644 web-ui/src/app/services/error.service.ts

diff --git a/web-ui/src/app/app.component.ts b/web-ui/src/app/app.component.ts
index 78a8b03..99e38a8 100644
--- a/web-ui/src/app/app.component.ts
+++ b/web-ui/src/app/app.component.ts
@@ -24,6 +24,7 @@ export class AppComponent {
 
   englishLang(): Object {
     return {
+      'message.serverUnavailable': 'The server unavailable, please try again in a minute',
       'action.find': 'Find',
       'label.transactionId': 'Transaction Id'
     };
diff --git a/web-ui/src/app/app.module.ts b/web-ui/src/app/app.module.ts
index e8380fb..283ca0d 100644
--- a/web-ui/src/app/app.module.ts
+++ b/web-ui/src/app/app.module.ts
@@ -12,6 +12,7 @@ import { ToastrModule } from 'ngx-toastr';
 
 import { NgHttpLoaderModule } from 'ng-http-loader/ng-http-loader.module'
 
+import { ErrorService } from './services/error.service';
 import { LanguageService } from './services/language.service';
 import { NotificationService } from './services/notification.service';
 import { TransactionsService } from './services/transactions.service';
@@ -50,6 +51,7 @@ import { TransactionFinderComponent } from './components/transaction-finder/tran
     TranslateModule.forRoot(),
   ],
   providers: [
+    ErrorService,
     LanguageService,
     NotificationService,
     TransactionsService
diff --git a/web-ui/src/app/services/error.service.ts b/web-ui/src/app/services/error.service.ts
new file mode 100644
index 0000000..a7a5051
--- /dev/null
+++ b/web-ui/src/app/services/error.service.ts
@@ -0,0 +1,92 @@
+import { Injectable } from '@angular/core';
+import { AbstractControl, FormGroup } from '@angular/forms/src/model';
+
+import { TranslateService } from '@ngx-translate/core';
+
+import { NotificationService } from './notification.service';
+
+@Injectable()
+export class ErrorService {
+
+  constructor(
+    private translateService: TranslateService,
+    private notificationService: NotificationService) { }
+
+  renderServerErrors(form: FormGroup, response: any) {
+    if (response.error.errors == null) {
+      // server error responses are consistent, if the errors array is not defined
+      // it is very likely that there are issues with the server.
+      this.translateService.get('message.serverUnavailable')
+        .subscribe(msg => this.notificationService.error(msg));
+
+      return;
+    }
+
+    response.error.errors.forEach((element: any) => {
+      // field errors are handled here, different errors should be handled globally
+      if (element.type === 'field-validation-error') {
+        const fieldName = element.field;
+        const message = element.message;
+        if (form == null || !this.hasFieldName(form, fieldName)) {
+          this.notificationService.error(`${fieldName}: ${message}`);
+        } else {
+          this.setFieldError(form, fieldName, message);
+        }
+      } else {
+        const message = element.message;
+        this.notificationService.error(message);
+      }
+    });
+  }
+
+  hasWrongValue(form: FormGroup, fieldName: string): boolean {
+    return this.getFieldErrors(form, fieldName).length > 0;
+  }
+
+  // a field is correct only if it is filled and have no errors
+  hasCorrectValue(form: FormGroup, fieldName: string): boolean {
+    const control = this.findFieldControl(form, fieldName);
+    // field found && user changed it && it doesn't hold a wrong value
+    const isCorrect = control && !control.pristine && !this.hasWrongValue(form, fieldName);
+
+    return isCorrect;
+  }
+
+  // right now we are rendering one error only for a field
+  getFieldError(form: FormGroup, fieldName: string): string {
+    return this.getFieldErrors(form, fieldName)[0];
+  }
+
+  getFieldErrors(form: FormGroup, fieldName: string): string[] {
+    const control = this.findFieldControl(form, fieldName);
+    if (control && control.touched && control.errors) {
+      return this.getErrors(control);
+    } else {
+      return [];
+    }
+  }
+
+  getErrors(control: AbstractControl): string[] {
+    return Object.keys(control.errors)
+      .filter((error: any) => control.errors[error])
+      .map((error: any) => {
+        const params = control.errors[error];
+        return error;
+      });
+  }
+
+  private hasFieldName(form: FormGroup, fieldName: string): boolean {
+    const control = this.findFieldControl(form, fieldName);
+    return control != null;
+  }
+
+  private setFieldError(form: FormGroup, fieldName: string, message: string) {
+    const control = this.findFieldControl(form, fieldName);
+    const errors = { [message]: true };
+    control.setErrors(errors);
+  }
+
+  private findFieldControl(form: FormGroup, fieldName: string): AbstractControl {
+    return form.get(fieldName);
+  }
+}