Ionic 3 – HTTP Requests – Retrieving a Photo from a Google Place

WRITTEN BY GARETH DUNNE @JSDIARIES

As I become more comfortable with Ionic 3 and its functionality, I wanted to share how to connect to the Google Maps API, retrieve a specific place and then to request a photo from that requested place.

In doing so, you will then know how define a HTTP object using TypeScript and using ES6 Promises in order to make a callback function that requests the photo using that HTTP object.

This functionality stems from an app that I made called CoffeeTrail.

Android Coffee Finder Application CoffeeTrail
CoffeeTrail

It’ll be on the iOS store very soon but be sure to check it out on Android here.

Setup Project

As always we can generate our Ionic 3 project using the command

We then want to generate our locations provider.

This is a provider that contains all our methods that we will use to request data from Google’s APIs. When you open up this locations provider you will see that the Ionic CLI has automatically injected a HTTP object into the constructor for us.

This is the object we will be using to make the requests.

We will also generate a location-details component that will display our requested images.

API Key

In order to have access to multiple API calls in our app we need to request a developer API key for Google Maps.

You can generate one by going to this page and clicking Get A Key , This is required for all place and photo requests and won’t work without one.

Google API Key
Google API Key

Get Place

We will create a getLocation method that will accept latitude and longitude as parameters.

We utilize a ES6 JavaScript Promise that will use the http object created in our constructor in order to make the request along with the details of the location which you can change for your own personal preferences.

You will of course have to reference the API key that you created earlier on in the apiKey variable of type string..

This Promise will return true or resolve when the the request has been completed and the data has been returned. The results of the data is mapped to a new json object which we assign to the this.data variable through ES6’s arrow functions .

This data will be resolved/returned when we call it in our location-details file.

We also can add the getPhoto method.

This will take in a photo reference string as a parameter in order to a retrieve a specific photo based on the location from the locations/location returned from our getLocation method.
So how do we get the photo reference from the data set returned from getLocation? Well we can do this in the locations-list file.

Display Photo

Our location-details.html file should look like this to display the retrieved image of the location.

Notice how we use the async pipe with the current image template variable.

This is because some asynchronous data objects can be a bit tricky to display without async pipe. The data source is an Observable that contains an array so using the async pipe secures it so to speak.

We then use the ng-template (which is new to Angular 4) syntax to display error text if no image can be retrieved.

So in our location.details.ts file we need to use our getLocation method in order to get a place and then to send a photo reference from that place to the getPhoto method.

This is just one way to retrieve data from an API in an Ionic application. The use of Angular 4 in an Ionic 3 project enables a developer to makes a request for some data and then to easily share that data throughout the rest of the components using a service or in this case, using our location.ts. provider.

Ionic 3 Release – Whats New?

WRITTEN BY GARETH DUNNE @JSDIARIES

Ionic 3 has released and with it, has brought some impressive but not overbearing changes to the Ionic framework.

While sites like Toptal have previously covered performance differences between Ionic 1 and 2.
This post will cover the upgrade from Ionic 2 to 3 and the performance differences that come with it.

Similar to the Angular 4 release, this isn’t a core change to the platform, rather it is adding some improvements to your applications that will increase overall performance and allows hybrid app development to come a few steps close to being on par with its native development counterparts.

As always here is some useful Ionic reading material. And here is the official post from the Ionic team specifying all the changes.

Updating from Ionic 2

Updating from Ionic 2 is actually quite a simple process. This video from Paul Halliday simplifies the process even further:

Angular 4

Ionic has been updated to be compatible with Angular 4 and all the features that come with it. You can find our Angular 4 release post here.

And the official Angular blog covers it here aswell.

Lazy Loading

One of the most notable features of the release, lazy loading provides us with the ability to breakdown our bundles for our application even further.

This allows our application to only load certain bundles/modules when they are actually needed. When you lazy load, your application performance improves, particular as the app is starting up because all the modules that were previously loaded in our app.module.ts are not requested at once rather they are loaded on a page by page basis.

I would highly recommend checking out Paul Hallidays tutorial on this:

TypeScript 2.1 and 2.2 compatibility

As specified on the official Ionic blog. Ionic 3 has been updated to be compatibly with Typescript versions 2.1 and 2.2. This is inline with **Angular 4 ** being compatible with these versions as well. More information can be found here.

A Promising future

So that just about summarizes the main changse for Ionic 3. I don’t think anyone can deny the momentum and progression that this framework has going for it.

While originally I was concentrating on all things Angular. Ionic has really provided such a sleek way to use web technologies in order to reach such a wider userbase and to target them more personally through mobile applications.

If you needed even more detail regarding Ionic 3 changes please check our Joshua Morony’s detailed guide here:

I highly recommend all his content as it provides a huge insight into all potential features you might want to implement into your application.