This post will show you how to implement a kind of “expiration” for your data objects. The strategy is sufficiently abstract, so it’s applicable to any resource you need to expire, including files, logs, and so on.
Since the database does not have any built-in expiration mechanism, we’ll have to implement it on our own. Fortunately, the task is pretty easy because we have access to Backendless Business Logic. The idea is to create a Timer, which is going to run with some fixed time period and delete the resources based on your criteria.
For each entry in a given table, Backendless creates a unique
objectId property – this is a UUID. In some cases, you may want to have a unique ID based on a whole number. To do this, we will use Backendless Atomic Counters (you can read the documentation about Atomic Counters here). In this article, we will use JavaScript business logic to create a handler that will add a unique value before creating the object. You can then store that value in your table to provide the ID you’re looking for.
One of the most powerful features that Backendless 5 has available is the capability for you to implement your own License Manager for creating and checking licenses for your product/customers. In this article, we will touch on some Backendless services such as data management and Business Logic and we will use one of the Backendless Client SDKs.
Backendless Cloud Code officially supports Java, JavaScript and Codeless. Since Kotlin compiles to Java byte code, it is not an exception and can be used as well to build API Services, Event handlers and Timers. Check out an article by @vvsevolodovich describing how to configure your project so you can develop Cloud Code logic with Kotlin:
Backendless 5 is now released (hooray!) and it offers a bunch of new powerful capabilities. One of them is support for development of custom Amazon Alexa Skills. In this post I am going to demonstrate how easy it is to create a custom skill using JavaScript. You will learn how to control the dialogue flow between the user and Alexa using Backendless and custom Cloud Code.
An example we will build a trip planner skill, albeit a trivialized version of it, which will gather from the user the departure date, the departure and arrival cities. The collected information can be used to search available fares, hotels and make any other necessary arrangements.
What You Will Need
- An Amazon Developer Account
- A Backendless Developer Account and App
- Install SDK for Amazon Alexa from Backendless Marketplace
We did it! There is a new SDK in the Backendless family of libraries, please welcome the SDK for Amazon Alexa! Let’s get a few basic questions out of the way first:
Q: Can I build a custom Amazon Alexa skill without Amazon Lambda?
A: Yes, you can definitely do it by running your custom skill implementation in Backendless.
Q: Can I build a custom Amazon Alexa skill with JavaScript, Java or without any programming language?
A: Yes, with Backendless you can implement a custom Alexa skill using Java, JavaScript or Codeless, which is a visual programming environment.
Q: What is the simplest way to build a custom Alexa skill?
A: Great question! Read the announcement below:
Today we will talk about how to monitor client’s Real-Time Connections in your Angular application. This tutorial continues the guide on how to build Angular apps with Backendless. It is recommended to check out the previous article in this series before you continue for the reason that we will use the application from the previous post as the starting point for this tutorial. Alternatively, if you just want to start working with the it right away, just download the source code from this GitHub commit.
In many cases we want to see how many application users are online or offline, for example, it might be useful in a chat application. For the demo purposes, in our application we will add a simple counter for count all connected clients. As we explore adding that functionality, you will meet with Backendless Business Logic, Backendless Counters, Codeless and keep discovering Real-Time features:
Images displayed in your app often may be responsible for the bandwidth consumed by the device, which has a direct impact on the performance, battery level and the amount of memory which the app allocates. As a result, optimizing images can often bring noticeable performance improvements for your app: the fewer bytes it needs to download, the smaller impact is on the client’s bandwidth and the faster app will download and render content on the screen.
Let’s imagine you have an app where you store pictures to show them to your app’s users. But what happens if the resolution of these images is high and they are taking a lot of space? Download of these files is time-consuming and, as a result, it slows down your app making the user experience substandard.
A recommended approach is to create image thumbnails with lower resolutions relative to the original one. These thumbnails can be used to preview the image in the application.
The thumbnails can be generated using Backendless API Services (the Business Logic section). If you are not familiar with how to create your own API Service, please check the How to generate a QR code with Backendless API Service post, which describes the process of API service creation in greater detail.
In this article, we will focus on the task of generating thumbnail images with different resolutions.
Suppose your app logs in a user. As a result, the app gets user-token which uniquely identifies the user’s session with Backendless. If your app uses our SDK for Android, iOS, JS or .NET, the user-token value is managed directly by our libraries. Specifically, it is added to every API call to maintain the session and tell the server about the user’s identity. There are situations when you need to get the user object when your app has only user-token. This could happen if you used persistent login in the application, which stores user-token on the device. The implementation does not save the user object, however, there is a way to retrieve the user based on the user-token value (assuming the token is still valid). In this article, I will show you how to do this.
The technique for retrieving the user object is creating an API service which accepts a user-token in the header and retrieves the current user. I will use Codeless to create the API service because it has an intuitive interface and allows you to solve these tasks very quickly, just by building the algorithms instead of writing code:
Backendless Marketplace is a specialized store for backend functionality. Our vision for the marketplace is to make it a community driven store for algorithms and API services. We also use the Marketplace for various Backendless”extenders” to help developers to increase the limits of the Backendless Cloud pricing plans. However, most importantly, the Marketplace can be used for sharing your API services with other developers.
By publishing your Cloud Code to the Marketplace, you can share your business logic components (e.g.: API services, event handlers and/or timers) with other Backendless developers. Once your Cloud Code is published, it becomes a Marketplace product and will be visible to all Backendless users (developers). In the upcoming releases, we’ll add a possibility to set a price for your products allowing you to charge a fee for every successful installation.
