Database example app with Room ORM

With Android Architecture Components getting a stable 1.0 version, there are now no excuses of not using it šŸ™‚ Along with handling lifecycle events, realtime data updates in UI (ViewModel with LiveData) and pagination of loaded data (Paging), comes Room – small, yet powerful SQLite ORM. In this post I’m gonna demonstrate its core capabilities on an example Android application.

Remember those times implementing SQLiteOpenHelper and checking SQL queries in run-time? Good news is that you don’t have to do it anymore! Room performs compile-time checks on your SQL queries and you don’t have to write any SQLite code which is not in a direct relation with your data queries. Great, lets use it!

First of all, Room is a part of Architecture Components, which means it works really well with ViewModel, LiveData and Paging (but does not depend on them!). Also, RxJava and Kotlin are perfectly fine too. In order to add Room to the project, I’m adding the following lines in app’s build.gradle file:

    // Room
    implementation "android.arch.persistence.room:runtime:1.0.0"
    annotationProcessor "android.arch.persistence.room:compiler:1.0.0"

Check for the latest library versionĀ here.

Additionally, provide a location of DB’s schema in defaultConfig scope. This way you can always check how it looks, maybe decide to modify your tables once you notice something in scheme.

   javaCompileOptions {
        annotationProcessorOptions {
            arguments = ["room.schemaLocation":
                                 "$projectDir/schemas".toString()]
        }
    }

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AppBarLayout scroll behavior with layout_scrollFlags

Since the introduction of AppBar in 2015, Android developers have spent lots of time styling and modifying it, making beautiful and unique apps.Ā The ways of modifying Toolbar and flexible area beneath it are quite impressive. Yet, still the entry threshold is quite high for those who want to make their first steps in Material design world.

Partly, this is because of an incomplete documentation and the lack of diverse examples. I, myself struggled to make the layout I wanted and as easy as it sounds – to make it scroll the way I want to. This was the moment I decided to write this blog post, so it helps others šŸ™‚

Maybe you want to scroll a Toolbar, so it hides completely and the only thing visible is the text? Or expand and collapse an image below the Toolbar? Or, doesn’tĀ matter if the user is on the bottom of the layout, – you want to show him a Toolbar immediately on a scroll up action (there is a description of various scrolling techniques here). All of this is possible and easy to do with scroll flags!

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Online courses: Learn new skills!

If your summer was lazy and sleepy, it’s about time to wake up and do something! Why wait till New Year’s resolutions if you can still learnĀ new skills this year? šŸ˜‰

Below I present a collection of online courses,Ā on a very different topics and various difficulty levels. Some of them are free and will take a weekend to finish and others are as long as a few school semesters. Your choice which one to master. All you need is the desire and determination, the rest is available on yourĀ fingertips, literally!


Introduction to Kotlin Programming [ Free Trial, ~5h of video materials ]


Women Techmakers Nanodegree Courses [ Member’s free, ~6 months ]

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Best resources to learn RxJava

Hi,

Some time ago I got interested in reactive programming and RxJava in particular. It’s gaining more popular in Android world and I often see RxJava as an obligatory skill for a Senior or Mid Android Developer position, that’s why learning it can be of a great benefit if you’re seeking a job šŸ˜‰ But even if not, it can simplify your app development, especially if you have lots of UI fields which you fill in with some changing data or if you want to have an interactive search, or while using Retrofit for you HTTP requests. There are even smaller libs for a particular task, like RxWear, RxNotifications or RxAndroidBle (find aĀ full list of such libs here). Choosing the right one will depend on your needs šŸ˜‰

And so today I just want to share a few resources which I found very useful whileĀ learning how RxJava and RxAndroid libraries work (and what are they at all :). I have basically reviewed what’s available on ReactiveX Tutorials listĀ (which is huge!)Ā and listed the most intuitive and easy to get below, as well as a few articles and tutorials I found on the Internet myself.

AĀ separate and an absolutely must positionĀ is aĀ RxJava for Android App Development free e-book. It’s very short (only 41 pages!), and it’s a piece of cake to read, believe me, because I read it before any other docs or tutorials, and it explained the most important principles just fine šŸ™‚

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