Rapid App Development with Live Reload

So far, we’ve seen how easy it is to develop a cross-platform app that works everywhere. The development experience is pretty quick, but what if I told you there was a way to go faster?

We can use the Ionic CLI’s Live Reload functionality to boost our productivity when building Ionic apps. When active, Live Reload will reload the browser and/or WebView when changes in the app are detected.

Live Reload

Remember ionic serve? That was Live Reload working in the browser, allowing us to iterate quickly.

We can also use it when developing on iOS and Android devices. This is particularly useful when writing code that interacts with native plugins. Since we need to run native plugin code on a device in order to verify that it works, having a way to quickly write code, build and deploy it, then test it is crucial to keeping up our development speed.

Let’s use Live Reload to implement photo deletion, the missing piece of our Photo Gallery feature. Select your platform of choice (iOS or Android) and connect a device to your computer. Next, run either command in a terminal, based on your chosen platform:

$ ionic cap run ios -l --external

$ ionic cap run android -l --external

The Live Reload server will start up, and the native IDE of choice will open if not opened already. Within the IDE, click the Play button to launch the app onto your device.

Deleting Photos

With Live Reload running and the app is open on your device, let’s implement photo deletion functionality. Open Tab2.vue then import the actionSheetController. We'll display an IonActionSheet with the option to delete a photo:

import {
  actionSheetController,
  IonPage,
  IonHeader,
  IonFab,
  IonFabButton,
  IonIcon,
  IonToolbar,
  IonTitle,
  IonContent,
  IonImg,
  IonGrid,
  IonRow,
  IonCol,
} from '@ionic/vue';
// other imports

Next, reference the deletePhoto function, which we'll create soon:

setup() {}
  const { photos, takePhoto, deletePhoto } = usePhotoGallery();
}

When a user clicks/taps on an image, we will show the action sheet. Add a click handler to the <ion-img> element:

<ion-img :src="photo.webviewPath" @click="showActionSheet(photo)"></ion-img>

Next, within setup(), call the create function to open a dialog with the option to either delete the selected photo or cancel (close) the dialog:

const showActionSheet = async (photo: UserPhoto) => {
  const actionSheet = await actionSheetController.create({
    header: 'Photos',
    buttons: [
      {
        text: 'Delete',
        role: 'destructive',
        icon: trash,
        handler: () => {
          deletePhoto(photo);
        },
      },
      {
        text: 'Cancel',
        icon: close,
        role: 'cancel',
        handler: () => {
          // Nothing to do, action sheet is automatically closed
        },
      },
    ],
  });
  await actionSheet.present();
};

Next, return the showActionSheet function:

return {
  photos,
  takePhoto,
  showActionSheet,
  camera,
  trash,
  close,
};

Next, we need to implement the deletePhoto method in the usePhotoGallery function. Open the file then add:

const deletePhoto = async (photo: UserPhoto) => {
  // Remove this photo from the Photos reference data array
  photos.value = photos.value.filter((p) => p.filepath !== photo.filepath);

  // delete photo file from filesystem
  const filename = photo.filepath.substr(photo.filepath.lastIndexOf('/') + 1);
  await Filesystem.deleteFile({
    path: filename,
    directory: Directory.Data,
  });
};

The selected photo is removed from the photos array first, then we delete the photo file using the Filesystem API.

Remember that removing the photo from the photos array triggers the cachePhotos function for us automatically:

const cachePhotos = () => {
  Preferences.set({
    key: PHOTO_STORAGE,
    value: JSON.stringify(photos.value),
  });
};

watch(photos, cachePhotos);

Finally, return the deletePhoto function:

return {
  photos,
  takePhoto,
  deletePhoto,
};

Save this file, then tap on a photo again and choose the "Delete" option. This time, the photo is deleted! Implemented much faster using Live Reload. 💪

In the final portion of this tutorial, we’ll walk you through the basics of the Appflow product used to build and deploy your application to users' devices.