Fix exception being thrown on invalid routes (#218)

Author: rafaelss95

src/app/pages/component-list/component-list.ts

@@ -3,7 +3,7 @@ import {
   DocumentationItems,
   DocCategory
 } from '../../shared/documentation-items/documentation-items';
-import {ActivatedRoute, RouterModule} from '@angular/router';
+import {ActivatedRoute, Router, RouterModule} from '@angular/router';
 import {ComponentPageTitle} from '../page-title/page-title';
 import {SvgViewerModule} from '../../shared/svg-viewer/svg-viewer';
 import {CommonModule} from '@angular/common';
@@ -19,10 +19,16 @@ export class ComponentList {
 
   constructor(public docItems: DocumentationItems,
               private _componentPageTitle: ComponentPageTitle,
-              private _route: ActivatedRoute) {
+              private _route: ActivatedRoute,
+              private router: Router) {
     _route.params.subscribe(p => {
       this.category = docItems.getCategoryById(p['id']);
-      this._componentPageTitle.title = this.category.name;
+
+      if (this.category) {
+        this._componentPageTitle.title = this.category.name;
+      } else {
+        this.router.navigate(['/categories']);
+      }
     });
   }
 }

src/app/pages/guide-viewer/guide-viewer.ts

@@ -1,5 +1,5 @@
 import {Component, NgModule} from '@angular/core';
-import {ActivatedRoute, RouterModule} from '@angular/router';
+import {ActivatedRoute, Router, RouterModule} from '@angular/router';
 import {GuideItem, GuideItems} from '../../shared/guide-items/guide-items';
 import {FooterModule} from '../../shared/footer/footer';
 import {DocViewerModule} from '../../shared/doc-viewer/doc-viewer-module';
@@ -13,9 +13,15 @@ import {DocViewerModule} from '../../shared/doc-viewer/doc-viewer-module';
 export class GuideViewer {
   guide: GuideItem;
 
-  constructor(private _route: ActivatedRoute, public guideItems: GuideItems) {
+  constructor(private _route: ActivatedRoute,
+              private router: Router,
+              public guideItems: GuideItems) {
     _route.params.subscribe(p => {
       this.guide = guideItems.getItemById(p['id']);
+
+      if (!this.guide) {
+        this.router.navigate(['/guides']);
+      }
     });
   }
 }