diff --git a/core/package.json b/core/package.json
index 508b1a527d..2457a7c3e3 100644
--- a/core/package.json
+++ b/core/package.json
@@ -53,7 +53,7 @@
     "stylelint-order": "~1.0.0",
     "swiper": "4.4.1",
     "tslint": "^5.10.0",
-    "tslint-ionic-rules": "0.0.20",
+    "tslint-ionic-rules": "0.0.21",
     "tslint-react": "^3.6.0",
     "typescript": "^2.9.2"
   },
diff --git a/core/src/components.d.ts b/core/src/components.d.ts
index b2370e43fb..6fcce7bf8e 100644
--- a/core/src/components.d.ts
+++ b/core/src/components.d.ts
@@ -2795,7 +2795,7 @@ export namespace Components {
     * Set the root for the current navigation stack.
     */
     'setRoot': <T extends NavComponent>(component: T, componentProps?: ComponentProps<T> | null | undefined, opts?: NavOptions | null | undefined, done?: TransitionDoneFn | undefined) => Promise<boolean>;
-    'setRouteId': (id: string, params: { [key: string]: any; } | undefined, direction: number) => Promise<RouteWrite>;
+    'setRouteId': (id: string, params: { [key: string]: any; } | undefined, direction: RouterDirection) => Promise<RouteWrite>;
     /**
     * If the nav component should allow for swipe-to-go-back.
     */
@@ -3626,7 +3626,7 @@ export namespace Components {
     'delegate'?: FrameworkDelegate;
     'getRouteId': () => Promise<RouteID | undefined>;
     'mode': Mode;
-    'setRouteId': (id: string, params: { [key: string]: any; } | undefined, direction: number) => Promise<RouteWrite>;
+    'setRouteId': (id: string, params: { [key: string]: any; } | undefined, direction: RouterDirection) => Promise<RouteWrite>;
     'swipeHandler'?: SwipeGestureHandler;
   }
   interface IonRouterOutletAttributes extends StencilHTMLAttributes {
@@ -3651,7 +3651,7 @@ export namespace Components {
     * Go back to previous page in the window.history.
     */
     'goBack': () => Promise<void>;
-    'navChanged': (intent: number) => Promise<boolean>;
+    'navChanged': (direction: RouterDirection) => Promise<boolean>;
     'printDebug': () => void;
     /**
     * Navigate to the specified URL.
diff --git a/core/src/components/nav/constants.ts b/core/src/components/nav/constants.ts
new file mode 100644
index 0000000000..dc9b0417ff
--- /dev/null
+++ b/core/src/components/nav/constants.ts
@@ -0,0 +1,5 @@
+export const LIFECYCLE_WILL_ENTER = 'ionViewWillEnter';
+export const LIFECYCLE_DID_ENTER = 'ionViewDidEnter';
+export const LIFECYCLE_WILL_LEAVE = 'ionViewWillLeave';
+export const LIFECYCLE_DID_LEAVE = 'ionViewDidLeave';
+export const LIFECYCLE_WILL_UNLOAD = 'ionViewWillUnload';
diff --git a/core/src/components/nav/nav-interface.ts b/core/src/components/nav/nav-interface.ts
index ee649df197..66d4e2ab47 100644
--- a/core/src/components/nav/nav-interface.ts
+++ b/core/src/components/nav/nav-interface.ts
@@ -1,4 +1,6 @@
-import { Animation, AnimationBuilder, ComponentRef, FrameworkDelegate, Mode, ViewController } from '../../interface';
+import { Animation, AnimationBuilder, ComponentRef, FrameworkDelegate, Mode } from '../../interface';
+
+import { ViewController } from './view-controller';
 
 export type NavDirection = 'back' | 'forward';
 
@@ -62,3 +64,5 @@ export interface TransitionInstruction {
   leavingRequiresTransition?: boolean;
   enteringRequiresTransition?: boolean;
 }
+
+export { ViewController };
diff --git a/core/src/components/nav/nav.tsx b/core/src/components/nav/nav.tsx
index d37213137d..92ba7f3ada 100644
--- a/core/src/components/nav/nav.tsx
+++ b/core/src/components/nav/nav.tsx
@@ -1,11 +1,11 @@
 import { Build, Component, Element, Event, EventEmitter, Method, Prop, QueueApi, Watch } from '@stencil/core';
 
-import { ViewLifecycle } from '../..';
-import { Animation, AnimationBuilder, ComponentProps, Config, FrameworkDelegate, Gesture, Mode, NavComponent, NavOptions, NavOutlet, NavResult, RouteID, RouteWrite, TransitionDoneFn, TransitionInstruction, ViewController } from '../../interface';
+import { Animation, AnimationBuilder, ComponentProps, Config, FrameworkDelegate, Gesture, Mode, NavComponent, NavOptions, NavOutlet, NavResult, RouteID, RouteWrite, RouterDirection, TransitionDoneFn, TransitionInstruction, ViewController } from '../../interface';
 import { assert } from '../../utils/helpers';
 import { TransitionOptions, lifecycle, setPageHidden, transition } from '../../utils/transition';
 
-import { ViewState, convertToViews, matches } from './view-controller';
+import { LIFECYCLE_DID_LEAVE, LIFECYCLE_WILL_LEAVE, LIFECYCLE_WILL_UNLOAD } from './constants';
+import { VIEW_STATE_ATTACHED, VIEW_STATE_DESTROYED, VIEW_STATE_NEW, convertToViews, matches } from './view-controller';
 
 @Component({
   tag: 'ion-nav',
@@ -124,7 +124,7 @@ export class Nav implements NavOutlet {
 
   componentDidUnload() {
     for (const view of this.views) {
-      lifecycle(view.element!, ViewLifecycle.WillUnload);
+      lifecycle(view.element!, LIFECYCLE_WILL_UNLOAD);
       view._destroy();
     }
 
@@ -324,7 +324,7 @@ export class Nav implements NavOutlet {
   setRouteId(
     id: string,
     params: ComponentProps | undefined,
-    direction: number
+    direction: RouterDirection
   ): Promise<RouteWrite> {
     const active = this.getActiveSync();
     if (matches(active, id, params)) {
@@ -354,7 +354,7 @@ export class Nav implements NavOutlet {
       }
     };
 
-    if (direction === 0) {
+    if (direction === 'root') {
       finish = this.setRoot(id, params, commonOpts);
     } else {
       const viewController = this.views.find(v => matches(v, id, params));
@@ -364,9 +364,9 @@ export class Nav implements NavOutlet {
           ...commonOpts,
           direction: 'back'
         });
-      } else if (direction === 1) {
+      } else if (direction === 'forward') {
         finish = this.push(id, params, commonOpts);
-      } else if (direction === -1) {
+      } else if (direction === 'back') {
         finish = this.setRoot(id, params, {
           ...commonOpts,
           direction: 'back',
@@ -502,7 +502,7 @@ export class Nav implements NavOutlet {
     if (ti.opts!.updateURL !== false && this.useRouter) {
       const router = this.win.document.querySelector('ion-router');
       if (router) {
-        const direction = result.direction === 'back' ? -1 : 1;
+        const direction = result.direction === 'back' ? 'back' : 'forward';
         router.navChanged(direction);
       }
     }
@@ -560,7 +560,7 @@ export class Nav implements NavOutlet {
         throw new Error('no views in the stack to be removed');
       }
 
-      if (enteringView && enteringView.state === ViewState.New) {
+      if (enteringView && enteringView.state === VIEW_STATE_NEW) {
         await enteringView.init(this.el);
       }
       this.postViewInit(enteringView, leavingView, ti);
@@ -645,7 +645,7 @@ export class Nav implements NavOutlet {
       if (nav && nav !== this) {
         throw new Error('inserted view was already inserted');
       }
-      if (view.state === ViewState.Destroyed) {
+      if (view.state === VIEW_STATE_DESTROYED) {
         throw new Error('inserted view was already destroyed');
       }
     }
@@ -749,9 +749,9 @@ export class Nav implements NavOutlet {
     // let's make sure, callbacks are zoned
     if (destroyQueue && destroyQueue.length > 0) {
       for (const view of destroyQueue) {
-        lifecycle(view.element, ViewLifecycle.WillLeave);
-        lifecycle(view.element, ViewLifecycle.DidLeave);
-        lifecycle(view.element, ViewLifecycle.WillUnload);
+        lifecycle(view.element, LIFECYCLE_WILL_LEAVE);
+        lifecycle(view.element, LIFECYCLE_DID_LEAVE);
+        lifecycle(view.element, LIFECYCLE_WILL_UNLOAD);
       }
 
       // once all lifecycle events has been delivered, we can safely detroy the views
@@ -837,7 +837,7 @@ export class Nav implements NavOutlet {
 
   private removeView(view: ViewController) {
     assert(
-      view.state === ViewState.Attached || view.state === ViewState.Destroyed,
+      view.state === VIEW_STATE_ATTACHED || view.state === VIEW_STATE_DESTROYED,
       'view state should be loaded or destroyed'
     );
 
@@ -873,7 +873,7 @@ export class Nav implements NavOutlet {
       if (i > activeViewIndex) {
         // this view comes after the active view
         // let's unload it
-        lifecycle(element, ViewLifecycle.WillUnload);
+        lifecycle(element, LIFECYCLE_WILL_UNLOAD);
         this.destroyView(view);
       } else if (i < activeViewIndex) {
         // this view comes before the active view
diff --git a/core/src/components/nav/test/nav-controller.spec.ts b/core/src/components/nav/test/nav-controller.spec.ts
index 44983af950..fe604f0d87 100644
--- a/core/src/components/nav/test/nav-controller.spec.ts
+++ b/core/src/components/nav/test/nav-controller.spec.ts
@@ -952,7 +952,7 @@ describe('NavController', () => {
           ? win.document.createElement(enteringView.component)
           : enteringView.element = enteringView.component as HTMLElement;
       }
-      enteringView.state = ViewState.Attached;
+      enteringView.state = VIEW_STATE_ATTACHED;
     };
     return navI;
   }
diff --git a/core/src/components/nav/view-controller.ts b/core/src/components/nav/view-controller.ts
index da06a1924a..99903f2335 100644
--- a/core/src/components/nav/view-controller.ts
+++ b/core/src/components/nav/view-controller.ts
@@ -2,15 +2,13 @@ import { ComponentProps, FrameworkDelegate } from '../../interface';
 import { attachComponent } from '../../utils/framework-delegate';
 import { assert } from '../../utils/helpers';
 
-export const enum ViewState {
-  New = 1,
-  Attached,
-  Destroyed
-}
+export const VIEW_STATE_NEW = 1;
+export const VIEW_STATE_ATTACHED = 2;
+export const VIEW_STATE_DESTROYED = 3;
 
 export class ViewController {
 
-  state: ViewState = ViewState.New;
+  state = VIEW_STATE_NEW;
   nav?: any;
   element?: HTMLElement;
   delegate?: FrameworkDelegate;
@@ -21,7 +19,7 @@ export class ViewController {
   ) {}
 
   async init(container: HTMLElement) {
-    this.state = ViewState.Attached;
+    this.state = VIEW_STATE_ATTACHED;
 
     if (!this.element) {
       const component = this.component;
@@ -33,7 +31,7 @@ export class ViewController {
    * DOM WRITE
    */
   _destroy() {
-    assert(this.state !== ViewState.Destroyed, 'view state must be ATTACHED');
+    assert(this.state !== VIEW_STATE_DESTROYED, 'view state must be ATTACHED');
 
     const element = this.element;
     if (element) {
@@ -44,7 +42,7 @@ export class ViewController {
       }
     }
     this.nav = undefined;
-    this.state = ViewState.Destroyed;
+    this.state = VIEW_STATE_DESTROYED;
   }
 }
 
diff --git a/core/src/components/router-outlet/route-outlet.tsx b/core/src/components/router-outlet/route-outlet.tsx
index 870e24054a..5a374fd507 100644
--- a/core/src/components/router-outlet/route-outlet.tsx
+++ b/core/src/components/router-outlet/route-outlet.tsx
@@ -1,6 +1,6 @@
 import { Component, ComponentInterface, Element, Event, EventEmitter, Method, Prop, QueueApi, Watch } from '@stencil/core';
 
-import { Animation, AnimationBuilder, ComponentProps, ComponentRef, Config, FrameworkDelegate, Gesture, Mode, NavOutlet, RouteID, RouteWrite, RouterOutletOptions, SwipeGestureHandler } from '../../interface';
+import { Animation, AnimationBuilder, ComponentProps, ComponentRef, Config, FrameworkDelegate, Gesture, Mode, NavOutlet, RouteID, RouteWrite, RouterDirection, RouterOutletOptions, SwipeGestureHandler } from '../../interface';
 import { transition } from '../../utils';
 import { attachComponent, detachComponent } from '../../utils/framework-delegate';
 
@@ -102,10 +102,10 @@ export class RouterOutlet implements ComponentInterface, NavOutlet {
 
   /** @internal */
   @Method()
-  async setRouteId(id: string, params: ComponentProps | undefined, direction: number): Promise<RouteWrite> {
+  async setRouteId(id: string, params: ComponentProps | undefined, direction: RouterDirection): Promise<RouteWrite> {
     const changed = await this.setRoot(id, params, {
-      duration: direction === 0 ? 0 : undefined,
-      direction: direction === -1 ? 'back' : 'forward',
+      duration: direction === 'root' ? 0 : undefined,
+      direction: direction === 'back' ? 'back' : 'forward',
     });
     return {
       changed,
diff --git a/core/src/components/router/router.tsx b/core/src/components/router/router.tsx
index b6d0ade2a2..2eba8ce468 100644
--- a/core/src/components/router/router.tsx
+++ b/core/src/components/router/router.tsx
@@ -3,7 +3,7 @@ import { Component, ComponentInterface, Element, Event, EventEmitter, Listen, Me
 import { BackButtonEvent, Config, RouteChain, RouterDirection, RouterEventDetail } from '../../interface';
 import { debounce } from '../../utils/helpers';
 
-import { RouterIntent } from './utils/constants';
+import { ROUTER_INTENT_BACK, ROUTER_INTENT_FORWARD, ROUTER_INTENT_NONE } from './utils/constants';
 import { printRedirects, printRoutes } from './utils/debug';
 import { readNavState, waitUntilNavNode, writeNavState } from './utils/dom';
 import { routeRedirect, routerIDsToChain, routerPathToChain } from './utils/matching';
@@ -97,9 +97,8 @@ export class Router implements ComponentInterface {
     console.debug('[ion-router] URL pushed -> updating nav', url, direction);
 
     const path = parsePath(url);
-    const intent = DIRECTION_TO_INTENT[direction];
-    this.setPath(path, intent);
-    return this.writeNavStateRoot(path, intent);
+    this.setPath(path, direction);
+    return this.writeNavStateRoot(path, direction);
   }
 
   /**
@@ -122,7 +121,7 @@ export class Router implements ComponentInterface {
 
   /** @internal */
   @Method()
-  async navChanged(intent: number): Promise<boolean> {
+  async navChanged(direction: RouterDirection): Promise<boolean> {
     if (this.busy) {
       console.warn('[ion-router] router is busy, navChanged was cancelled');
       return false;
@@ -142,21 +141,21 @@ export class Router implements ComponentInterface {
     }
 
     console.debug('[ion-router] nav changed -> update URL', ids, path);
-    this.setPath(path, intent);
+    this.setPath(path, direction);
 
-    await this.safeWriteNavState(outlet, chain, RouterIntent.None, path, null, ids.length);
+    await this.safeWriteNavState(outlet, chain, ROUTER_INTENT_NONE, path, null, ids.length);
     return true;
   }
 
   private onRedirectChanged() {
     const path = this.getPath();
     if (path && routeRedirect(path, readRedirects(this.el))) {
-      this.writeNavStateRoot(path, RouterIntent.None);
+      this.writeNavStateRoot(path, ROUTER_INTENT_NONE);
     }
   }
 
   private onRoutesChanged() {
-    return this.writeNavStateRoot(this.getPath(), RouterIntent.None);
+    return this.writeNavStateRoot(this.getPath(), ROUTER_INTENT_NONE);
   }
 
   private historyDirection() {
@@ -172,15 +171,15 @@ export class Router implements ComponentInterface {
     this.lastState = state;
 
     if (state > lastState) {
-      return RouterIntent.Forward;
+      return ROUTER_INTENT_FORWARD;
     } else if (state < lastState) {
-      return RouterIntent.Back;
+      return ROUTER_INTENT_BACK;
     } else {
-      return RouterIntent.None;
+      return ROUTER_INTENT_NONE;
     }
   }
 
-  private async writeNavStateRoot(path: string[] | null, intent: RouterIntent): Promise<boolean> {
+  private async writeNavStateRoot(path: string[] | null, direction: RouterDirection): Promise<boolean> {
     if (!path) {
       console.error('[ion-router] URL is not part of the routing set');
       return false;
@@ -191,7 +190,7 @@ export class Router implements ComponentInterface {
     const redirect = routeRedirect(path, redirects);
     let redirectFrom: string[] | null = null;
     if (redirect) {
-      this.setPath(redirect.to!, intent);
+      this.setPath(redirect.to!, direction);
       redirectFrom = redirect.from;
       path = redirect.to!;
     }
@@ -205,18 +204,18 @@ export class Router implements ComponentInterface {
     }
 
     // write DOM give
-    return this.safeWriteNavState(this.win.document.body, chain, intent, path, redirectFrom);
+    return this.safeWriteNavState(this.win.document.body, chain, direction, path, redirectFrom);
   }
 
   private async safeWriteNavState(
-    node: HTMLElement | undefined, chain: RouteChain, intent: RouterIntent,
+    node: HTMLElement | undefined, chain: RouteChain, direction: RouterDirection,
     path: string[], redirectFrom: string[] | null,
     index = 0
   ): Promise<boolean> {
     const unlock = await this.lock();
     let changed = false;
     try {
-      changed = await this.writeNavState(node, chain, intent, path, redirectFrom, index);
+      changed = await this.writeNavState(node, chain, direction, path, redirectFrom, index);
     } catch (e) {
       console.error(e);
     }
@@ -236,7 +235,7 @@ export class Router implements ComponentInterface {
   }
 
   private async writeNavState(
-    node: HTMLElement | undefined, chain: RouteChain, intent: RouterIntent,
+    node: HTMLElement | undefined, chain: RouteChain, direction: RouterDirection,
     path: string[], redirectFrom: string[] | null,
     index = 0
   ): Promise<boolean> {
@@ -252,7 +251,7 @@ export class Router implements ComponentInterface {
       this.ionRouteWillChange.emit(routeEvent);
     }
 
-    const changed = await writeNavState(node, chain, intent, index);
+    const changed = await writeNavState(node, chain, direction, index);
     this.busy = false;
 
     if (changed) {
@@ -266,9 +265,9 @@ export class Router implements ComponentInterface {
     return changed;
   }
 
-  private setPath(path: string[], intent: RouterIntent) {
+  private setPath(path: string[], direction: RouterDirection) {
     this.state++;
-    writePath(this.win.history, this.root, this.useHash, path, intent, this.state);
+    writePath(this.win.history, this.root, this.useHash, path, direction, this.state);
   }
 
   private getPath(): string[] | null {
@@ -290,9 +289,3 @@ export class Router implements ComponentInterface {
     };
   }
 }
-
-const DIRECTION_TO_INTENT = {
-  'back': RouterIntent.Back,
-  'root': RouterIntent.None,
-  'forward': RouterIntent.Forward
-};
diff --git a/core/src/components/router/test/path.spec.tsx b/core/src/components/router/test/path.spec.tsx
index 6bc2749928..1c8306b3a2 100644
--- a/core/src/components/router/test/path.spec.tsx
+++ b/core/src/components/router/test/path.spec.tsx
@@ -1,4 +1,4 @@
-import { RouterIntent } from '../utils/constants';
+import { ROUTER_INTENT_FORWARD } from '../utils/constants';
 import { RouteChain } from '../utils/interface';
 import { chainToPath, generatePath, parsePath, readPath, writePath } from '../utils/path';
 
@@ -178,61 +178,61 @@ describe('readPath', () => {
 describe('writePath', () => {
   it('should write root path (no hash)', () => {
     const history = mockHistory();
-    writePath(history, '', false, [''], RouterIntent.Forward, 123);
+    writePath(history, '', false, [''], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '/');
 
-    writePath(history, '', false, ['schedule'], RouterIntent.Forward, 123);
+    writePath(history, '', false, ['schedule'], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '/schedule');
 
-    writePath(history, '/', false, [''], RouterIntent.Forward, 123);
+    writePath(history, '/', false, [''], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '/');
 
-    writePath(history, '/', false, ['to', 'schedule'], RouterIntent.Forward, 123);
+    writePath(history, '/', false, ['to', 'schedule'], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '/to/schedule');
   });
 
   it('should write non root path (no hash)', () => {
     const history = mockHistory();
-    writePath(history, '/path', false, [''], RouterIntent.Forward, 2);
+    writePath(history, '/path', false, [''], ROUTER_INTENT_FORWARD, 2);
     expect(history.pushState).toHaveBeenCalledWith(2, '', '/path');
 
-    writePath(history, '/path', false, ['to', 'page'], RouterIntent.Forward, 2);
+    writePath(history, '/path', false, ['to', 'page'], ROUTER_INTENT_FORWARD, 2);
     expect(history.pushState).toHaveBeenCalledWith(2, '', '/path/to/page');
 
-    writePath(history, 'path/to', false, ['second', 'page'], RouterIntent.Forward, 2);
+    writePath(history, 'path/to', false, ['second', 'page'], ROUTER_INTENT_FORWARD, 2);
     expect(history.pushState).toHaveBeenCalledWith(2, '', '/path/to/second/page');
 
-    writePath(history, '/path/to/', false, ['second', 'page'], RouterIntent.Forward, 2);
+    writePath(history, '/path/to/', false, ['second', 'page'], ROUTER_INTENT_FORWARD, 2);
     expect(history.pushState).toHaveBeenCalledWith(2, '', '/path/to/second/page');
   });
 
   it('should write root path (no hash)', () => {
     const history = mockHistory();
-    writePath(history, '', true, [''], RouterIntent.Forward, 123);
+    writePath(history, '', true, [''], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/');
 
-    writePath(history, '', true, ['schedule'], RouterIntent.Forward, 123);
+    writePath(history, '', true, ['schedule'], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/schedule');
 
-    writePath(history, '/', true, [''], RouterIntent.Forward, 123);
+    writePath(history, '/', true, [''], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/');
 
-    writePath(history, '/', true, ['to', 'schedule'], RouterIntent.Forward, 123);
+    writePath(history, '/', true, ['to', 'schedule'], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/to/schedule');
   });
 
   it('should write non root path (no hash)', () => {
     const history = mockHistory();
-    writePath(history, '/path', true, [''], RouterIntent.Forward, 123);
+    writePath(history, '/path', true, [''], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/path');
 
-    writePath(history, '/path', true, ['to', 'page'], RouterIntent.Forward, 123);
+    writePath(history, '/path', true, ['to', 'page'], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/path/to/page');
 
-    writePath(history, 'path/to', true, ['second', 'page'], RouterIntent.Forward, 123);
+    writePath(history, 'path/to', true, ['second', 'page'], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/path/to/second/page');
 
-    writePath(history, '/path/to/', true, ['second', 'page'], RouterIntent.Forward, 123);
+    writePath(history, '/path/to/', true, ['second', 'page'], ROUTER_INTENT_FORWARD, 123);
     expect(history.pushState).toHaveBeenCalledWith(123, '', '#/path/to/second/page');
   });
 });
diff --git a/core/src/components/router/utils/constants.ts b/core/src/components/router/utils/constants.ts
index 75de3b7d3e..7f47d466b3 100644
--- a/core/src/components/router/utils/constants.ts
+++ b/core/src/components/router/utils/constants.ts
@@ -1,6 +1,4 @@
 
-export const enum RouterIntent {
-  None = 0,
-  Forward = 1,
-  Back = -1,
-}
+export const ROUTER_INTENT_NONE = 'root';
+export const ROUTER_INTENT_FORWARD = 'forward';
+export const ROUTER_INTENT_BACK = 'back';
diff --git a/core/src/components/router/utils/dom.ts b/core/src/components/router/utils/dom.ts
index 0e728763ed..e92300f595 100644
--- a/core/src/components/router/utils/dom.ts
+++ b/core/src/components/router/utils/dom.ts
@@ -1,11 +1,11 @@
-import { NavOutletElement, RouteChain, RouteID } from '../../../interface';
+import { NavOutletElement, RouteChain, RouteID, RouterDirection } from '../../../interface';
 
-import { RouterIntent } from './constants';
+import { ROUTER_INTENT_NONE } from './constants';
 
 export async function writeNavState(
   root: HTMLElement | undefined,
   chain: RouteChain,
-  intent: RouterIntent,
+  direction: RouterDirection,
   index: number,
   changed = false
 ): Promise<boolean> {
@@ -20,17 +20,17 @@ export async function writeNavState(
     await outlet.componentOnReady();
 
     const route = chain[index];
-    const result = await outlet.setRouteId(route.id, route.params, intent);
+    const result = await outlet.setRouteId(route.id, route.params, direction);
 
     // if the outlet changed the page, reset navigation to neutral (no direction)
     // this means nested outlets will not animate
     if (result.changed) {
-      intent = RouterIntent.None;
+      direction = ROUTER_INTENT_NONE;
       changed = true;
     }
 
     // recursively set nested outlets
-    changed = await writeNavState(result.element, chain, intent, index + 1, changed);
+    changed = await writeNavState(result.element, chain, direction, index + 1, changed);
 
     // once all nested outlets are visible let's make the parent visible too,
     // using markVisible prevents flickering
diff --git a/core/src/components/router/utils/interface.ts b/core/src/components/router/utils/interface.ts
index a1aa379f34..16b8eeb5a5 100644
--- a/core/src/components/router/utils/interface.ts
+++ b/core/src/components/router/utils/interface.ts
@@ -1,7 +1,7 @@
 import { ComponentProps } from '../../../interface';
 
 export interface NavOutlet {
-  setRouteId(id: string, params: ComponentProps | undefined, direction: number): Promise<RouteWrite>;
+  setRouteId(id: string, params: ComponentProps | undefined, direction: RouterDirection): Promise<RouteWrite>;
   getRouteId(): Promise<RouteID | undefined>;
 }
 
diff --git a/core/src/components/router/utils/path.ts b/core/src/components/router/utils/path.ts
index b0c05b6539..16f91baaa3 100644
--- a/core/src/components/router/utils/path.ts
+++ b/core/src/components/router/utils/path.ts
@@ -1,6 +1,6 @@
-import { RouteChain } from '../../../interface';
+import { RouteChain, RouterDirection } from '../../../interface';
 
-import { RouterIntent } from './constants';
+import { ROUTER_INTENT_FORWARD } from './constants';
 
 export function generatePath(segments: string[]): string {
   const path = segments
@@ -28,7 +28,7 @@ export function chainToPath(chain: RouteChain): string[] | null {
   return path;
 }
 
-export function writePath(history: History, root: string, useHash: boolean, path: string[], intent: RouterIntent, state: number) {
+export function writePath(history: History, root: string, useHash: boolean, path: string[], direction: RouterDirection, state: number) {
   let url = generatePath([
     ...parsePath(root),
     ...path
@@ -36,7 +36,7 @@ export function writePath(history: History, root: string, useHash: boolean, path
   if (useHash) {
     url = '#' + url;
   }
-  if (intent === RouterIntent.Forward) {
+  if (direction === ROUTER_INTENT_FORWARD) {
     history.pushState(state, '', url);
   } else {
     history.replaceState(state, '', url);
diff --git a/core/src/components/tabs/tabs.tsx b/core/src/components/tabs/tabs.tsx
index 8e0791509f..19008f977a 100644
--- a/core/src/components/tabs/tabs.tsx
+++ b/core/src/components/tabs/tabs.tsx
@@ -187,7 +187,7 @@ export class Tabs implements NavOutlet {
     if (this.useRouter) {
       const router = this.doc.querySelector('ion-router');
       if (router) {
-        return router.navChanged(1);
+        return router.navChanged('forward');
       }
     }
     return Promise.resolve(false);
diff --git a/core/src/components/virtual-scroll/constants.ts b/core/src/components/virtual-scroll/constants.ts
new file mode 100644
index 0000000000..6f05ddce7e
--- /dev/null
+++ b/core/src/components/virtual-scroll/constants.ts
@@ -0,0 +1,7 @@
+export const CELL_TYPE_ITEM = 'item';
+export const CELL_TYPE_HEADER = 'header';
+export const CELL_TYPE_FOOTER = 'footer';
+
+export const NODE_CHANGE_NONE = 0;
+export const NODE_CHANGE_POSITION = 1;
+export const NODE_CHANGE_CELL = 2;
diff --git a/core/src/components/virtual-scroll/test/virtual-scroll-utils.spec.ts b/core/src/components/virtual-scroll/test/virtual-scroll-utils.spec.ts
index e5691417e2..36efc1c9f5 100644
--- a/core/src/components/virtual-scroll/test/virtual-scroll-utils.spec.ts
+++ b/core/src/components/virtual-scroll/test/virtual-scroll-utils.spec.ts
@@ -1,6 +1,6 @@
 import { HeaderFn, ItemHeightFn, VirtualNode } from '../../../interface';
-import { CellType } from '../virtual-scroll-interface';
 import { Range, calcCells, calcHeightIndex, getRange, getShouldUpdate, getViewport, positionForIndex, resizeBuffer, updateVDom } from '../virtual-scroll-utils';
+import { CELL_TYPE_ITEM, CELL_TYPE_HEADER, CELL_TYPE_FOOTER } from '../constants';
 
 describe('getViewport', () => {
   it('should return viewport without margin', () => {
@@ -149,7 +149,7 @@ describe('calcCells', () => {
     const cells = calcCells(items, undefined, undefined, undefined, 10, 20, 30, 0, 0, items.length);
     expect(cells).toEqual([
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: '0',
         i: 0,
         index: 0,
@@ -158,7 +158,7 @@ describe('calcCells', () => {
         visible: false,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: 2,
         i: 1,
         index: 1,
@@ -167,7 +167,7 @@ describe('calcCells', () => {
         visible: false,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: 'hola',
         i: 2,
         index: 2,
@@ -176,7 +176,7 @@ describe('calcCells', () => {
         visible: false,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: { data: 'hello' },
         i: 3,
         index: 3,
@@ -200,7 +200,7 @@ describe('calcCells', () => {
     expect(called).toEqual(3);
     expect(cells).toEqual([
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: 10,
         i: 0,
         index: 0,
@@ -209,7 +209,7 @@ describe('calcCells', () => {
         visible: true,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: 9,
         i: 1,
         index: 1,
@@ -218,7 +218,7 @@ describe('calcCells', () => {
         visible: true,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: 8,
         i: 2,
         index: 2,
@@ -258,7 +258,7 @@ describe('calcCells', () => {
     expect(footerCalled).toEqual(3);
     expect(cells).toEqual([
       {
-        type: CellType.Header,
+        type: CELL_TYPE_HEADER,
         value: 'my header',
         i: 0,
         index: 0,
@@ -267,7 +267,7 @@ describe('calcCells', () => {
         visible: false,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: '10',
         i: 1,
         index: 0,
@@ -276,7 +276,7 @@ describe('calcCells', () => {
         visible: true,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: '9',
         i: 2,
         index: 1,
@@ -285,7 +285,7 @@ describe('calcCells', () => {
         visible: true,
       },
       {
-        type: CellType.Item,
+        type: CELL_TYPE_ITEM,
         value: '8',
         i: 3,
         index: 2,
@@ -294,7 +294,7 @@ describe('calcCells', () => {
         visible: true,
       },
       {
-        type: CellType.Footer,
+        type: CELL_TYPE_FOOTER,
         value: 'my footer',
         i: 4,
         index: 2,
diff --git a/core/src/components/virtual-scroll/virtual-scroll-interface.ts b/core/src/components/virtual-scroll/virtual-scroll-interface.ts
index 852c43d5cf..0ee68d3ae7 100644
--- a/core/src/components/virtual-scroll/virtual-scroll-interface.ts
+++ b/core/src/components/virtual-scroll/virtual-scroll-interface.ts
@@ -1,16 +1,4 @@
 
-export const enum CellType {
-  Item,
-  Header,
-  Footer
-}
-
-export const enum NodeChange {
-  NoChange,
-  Position,
-  Cell,
-}
-
 export interface Cell {
   i: number;
   index: number;
@@ -29,6 +17,8 @@ export interface VirtualNode {
   visible: boolean;
 }
 
+export type CellType = 'item' | 'header' | 'footer';
+export type NodeChange = number;
 export type HeaderFn = (item: any, index: number, items: any[]) => string | null | undefined;
 export type ItemHeightFn = (item: any, index: number) => number;
 export type ItemRenderFn = (el: HTMLElement | null, cell: Cell, domIndex: number) => HTMLElement;
diff --git a/core/src/components/virtual-scroll/virtual-scroll-utils.ts b/core/src/components/virtual-scroll/virtual-scroll-utils.ts
index 6ea895a50e..7ef3ae64a8 100644
--- a/core/src/components/virtual-scroll/virtual-scroll-utils.ts
+++ b/core/src/components/virtual-scroll/virtual-scroll-utils.ts
@@ -1,6 +1,7 @@
 import { Cell, HeaderFn, ItemHeightFn, ItemRenderFn, VirtualNode } from '../../interface';
 
-import { CellType, NodeChange } from './virtual-scroll-interface';
+import { CELL_TYPE_FOOTER, CELL_TYPE_HEADER, CELL_TYPE_ITEM, NODE_CHANGE_CELL, NODE_CHANGE_NONE, NODE_CHANGE_POSITION } from './constants';
+import { CellType } from './virtual-scroll-interface';
 
 export interface Viewport {
   top: number;
@@ -17,7 +18,7 @@ const MIN_READS = 2;
 export function updateVDom(dom: VirtualNode[], heightIndex: Uint32Array, cells: Cell[], range: Range) {
   // reset dom
   for (const node of dom) {
-    node.change = NodeChange.NoChange;
+    node.change = NODE_CHANGE_NONE;
     node.d = true;
   }
 
@@ -32,7 +33,7 @@ export function updateVDom(dom: VirtualNode[], heightIndex: Uint32Array, cells:
       const top = heightIndex[i];
       if (top !== node.top) {
         node.top = top;
-        node.change = NodeChange.Position;
+        node.change = NODE_CHANGE_POSITION;
       }
       node.d = false;
     } else {
@@ -48,7 +49,7 @@ export function updateVDom(dom: VirtualNode[], heightIndex: Uint32Array, cells:
     const index = cell.index;
     if (node) {
       node.d = false;
-      node.change = NodeChange.Cell;
+      node.change = NODE_CHANGE_CELL;
       node.cell = cell;
       node.top = heightIndex[index];
     } else {
@@ -56,7 +57,7 @@ export function updateVDom(dom: VirtualNode[], heightIndex: Uint32Array, cells:
         d: false,
         cell,
         visible: true,
-        change: NodeChange.Cell,
+        change: NODE_CHANGE_CELL,
         top: heightIndex[index],
       });
     }
@@ -64,7 +65,7 @@ export function updateVDom(dom: VirtualNode[], heightIndex: Uint32Array, cells:
   dom
   .filter(n => n.d && n.top !== -9999)
   .forEach(n => {
-    n.change = NodeChange.Position;
+    n.change = NODE_CHANGE_POSITION;
     n.top = -9999;
   });
 }
@@ -83,7 +84,7 @@ export function doRender(
     const cell = node.cell;
 
     // the cell change, the content must be updated
-    if (node.change === NodeChange.Cell) {
+    if (node.change === NODE_CHANGE_CELL) {
       if (i < childrenNu) {
         child = children[i] as HTMLElement;
         nodeRender(child, cell, i);
@@ -99,7 +100,7 @@ export function doRender(
     }
 
     // only update position when it changes
-    if (node.change !== NodeChange.NoChange) {
+    if (node.change !== NODE_CHANGE_NONE) {
       child.style.transform = `translate3d(0,${node.top}px,0)`;
     }
 
@@ -132,9 +133,9 @@ function createNode(el: HTMLElement, type: CellType): HTMLElement | null {
 
 function getTemplate(el: HTMLElement, type: CellType): HTMLTemplateElement | null {
   switch (type) {
-    case CellType.Item: return el.querySelector('template:not([name])');
-    case CellType.Header: return el.querySelector('template[name=header]');
-    case CellType.Footer: return el.querySelector('template[name=footer]');
+    case CELL_TYPE_ITEM: return el.querySelector('template:not([name])');
+    case CELL_TYPE_HEADER: return el.querySelector('template[name=header]');
+    case CELL_TYPE_FOOTER: return el.querySelector('template[name=footer]');
   }
 }
 
@@ -220,7 +221,7 @@ export function calcCells(
       if (value != null) {
         cells.push({
           i: j++,
-          type: CellType.Header,
+          type: CELL_TYPE_HEADER,
           value,
           index: i,
           height: approxHeaderHeight,
@@ -232,7 +233,7 @@ export function calcCells(
 
     cells.push({
       i: j++,
-      type: CellType.Item,
+      type: CELL_TYPE_ITEM,
       value: item,
       index: i,
       height: itemHeight ? itemHeight(item, i) : approxItemHeight,
@@ -245,7 +246,7 @@ export function calcCells(
       if (value != null) {
         cells.push({
           i: j++,
-          type: CellType.Footer,
+          type: CELL_TYPE_FOOTER,
           value,
           index: i,
           height: approxFooterHeight,
@@ -283,7 +284,7 @@ export function resizeBuffer(buf: Uint32Array | undefined, len: number) {
 }
 
 export function positionForIndex(index: number, cells: Cell[], heightIndex: Uint32Array): number {
-  const cell = cells.find(c => c.type === CellType.Item && c.index === index);
+  const cell = cells.find(c => c.type === CELL_TYPE_ITEM && c.index === index);
   if (cell) {
     return heightIndex[cell.i];
   }
diff --git a/core/src/components/virtual-scroll/virtual-scroll.tsx b/core/src/components/virtual-scroll/virtual-scroll.tsx
index 4ace465926..76ddc3c62f 100644
--- a/core/src/components/virtual-scroll/virtual-scroll.tsx
+++ b/core/src/components/virtual-scroll/virtual-scroll.tsx
@@ -2,7 +2,7 @@ import { Component, ComponentInterface, Element, EventListenerEnable, Functional
 
 import { Cell, DomRenderFn, HeaderFn, ItemHeightFn, ItemRenderFn, VirtualNode } from '../../interface';
 
-import { CellType } from './virtual-scroll-interface';
+import { CELL_TYPE_FOOTER, CELL_TYPE_HEADER, CELL_TYPE_ITEM } from './constants';
 import { Range, calcCells, calcHeightIndex, doRender, findCellIndex, getRange, getShouldUpdate, getViewport, inplaceUpdate, positionForIndex, resizeBuffer, updateVDom } from './virtual-scroll-utils';
 
 @Component({
@@ -411,9 +411,9 @@ export class VirtualScroll implements ComponentInterface {
   private renderVirtualNode(node: VirtualNode) {
     const { type, value, index } = node.cell;
     switch (type) {
-      case CellType.Item: return this.renderItem!(value, index);
-      case CellType.Header: return this.renderHeader!(value, index);
-      case CellType.Footer: return this.renderFooter!(value, index);
+      case CELL_TYPE_ITEM: return this.renderItem!(value, index);
+      case CELL_TYPE_HEADER: return this.renderHeader!(value, index);
+      case CELL_TYPE_FOOTER: return this.renderFooter!(value, index);
     }
   }
 
diff --git a/core/src/index.ts b/core/src/index.ts
index 699c210e96..03a860c41e 100644
--- a/core/src/index.ts
+++ b/core/src/index.ts
@@ -1,14 +1,2 @@
-
-// lifecycle
-export const enum ViewLifecycle {
-  WillEnter = 'ionViewWillEnter',
-  DidEnter = 'ionViewDidEnter',
-  WillLeave = 'ionViewWillLeave',
-  DidLeave = 'ionViewDidLeave',
-  WillUnload = 'ionViewWillUnload',
-}
-
-// util functions
 export * from './utils/platform';
 export * from './utils/config';
-export * from './utils/gesture/swipe-back';
diff --git a/core/src/interface.d.ts b/core/src/interface.d.ts
index 795e7fa221..af60a9b9e3 100644
--- a/core/src/interface.d.ts
+++ b/core/src/interface.d.ts
@@ -4,18 +4,18 @@ export * from './index';
 export * from './components/animation-controller/animation-interface';
 export * from './components/alert/alert-interface';
 export * from './components/action-sheet/action-sheet-interface';
+export * from './components/content/content-interface';
 export * from './components/datetime/datetime-interface';
+export * from './components/loading/loading-interface';
 export * from './components/menu/menu-interface';
 export * from './components/modal/modal-interface';
-export * from './components/picker/picker-interface';
-export * from './components/loading/loading-interface';
-export * from './components/popover/popover-interface';
 export * from './components/nav/nav-interface';
-export * from './components/router/utils/interface';
+export * from './components/picker/picker-interface';
+export * from './components/popover/popover-interface';
 export * from './components/range/range-interface';
+export * from './components/router/utils/interface';
 export * from './components/refresher/refresher-interface';
 export * from './components/reorder-group/reorder-group-interface';
-export * from './components/content/content-interface';
 export * from './components/segment-button/segment-button-interface';
 export * from './components/select/select-interface';
 export * from './components/select-popover/select-popover-interface';
@@ -26,7 +26,6 @@ export * from './components/virtual-scroll/virtual-scroll-interface';
 
 // TODO: review how this types are exported
 // Other types
-export * from './components/nav/view-controller';
 
 export { Gesture, GestureDetail } from './utils/gesture/gesture';
 
diff --git a/core/src/utils/transition.ts b/core/src/utils/transition.ts
index dcfa5daf51..85d6b20f58 100644
--- a/core/src/utils/transition.ts
+++ b/core/src/utils/transition.ts
@@ -1,6 +1,6 @@
 import { QueueApi } from '@stencil/core';
 
-import { ViewLifecycle } from '..';
+import { LIFECYCLE_DID_ENTER, LIFECYCLE_DID_LEAVE, LIFECYCLE_WILL_ENTER, LIFECYCLE_WILL_LEAVE } from '../components/nav/constants';
 import { Animation, AnimationBuilder, NavDirection, NavOptions } from '../interface';
 
 const iosTransitionAnimation = () => import('./animations/ios.transition');
@@ -148,22 +148,22 @@ function playTransition(trans: Animation, opts: TransitionOptions): Promise<Anim
 }
 
 function fireWillEvents(enteringEl: HTMLElement | undefined, leavingEl: HTMLElement | undefined) {
-  lifecycle(leavingEl, ViewLifecycle.WillLeave);
-  lifecycle(enteringEl, ViewLifecycle.WillEnter);
+  lifecycle(leavingEl, LIFECYCLE_WILL_LEAVE);
+  lifecycle(enteringEl, LIFECYCLE_WILL_ENTER);
 }
 
 function fireDidEvents(enteringEl: HTMLElement | undefined, leavingEl: HTMLElement | undefined) {
-  lifecycle(enteringEl, ViewLifecycle.DidEnter);
-  lifecycle(leavingEl, ViewLifecycle.DidLeave);
+  lifecycle(enteringEl, LIFECYCLE_DID_ENTER);
+  lifecycle(leavingEl, LIFECYCLE_DID_LEAVE);
 }
 
-export function lifecycle(el: HTMLElement | undefined, eventName: ViewLifecycle) {
+export function lifecycle(el: HTMLElement | undefined, eventName: string) {
   if (el) {
-    const event = new CustomEvent(eventName, {
+    const ev = new CustomEvent(eventName, {
       bubbles: false,
       cancelable: false,
     });
-    el.dispatchEvent(event);
+    el.dispatchEvent(ev);
   }
 }
 
diff --git a/core/tslint.json b/core/tslint.json
index 799a5ef95c..10f4c2b230 100644
--- a/core/tslint.json
+++ b/core/tslint.json
@@ -17,6 +17,7 @@
     "no-unbound-method": true,
     "no-floating-promises": false,
     "no-invalid-template-strings": true,
+    "ban-export-const-enum": true,
 
     "jsx-key": false,
     "jsx-self-close": false,