Data Binding and You

Lightning talk overview of data binding on Android. Presented at Airbnb's Taking Flight, May 31st, San Francisco, CA.

Transcript

1. Data Binding and You Siena Aguayo Software Engineer, Indiegogo @sienatime
2. @sienatime What is data binding?
3. @sienatime Attaches model data to your view public class Pikachu { public String name = "Pikachu"; public String genus = "Mouse"; public String type = "Electric"; public int imageResource = R.drawable.sprite_25; }
4. @sienatime One- and Two-Way Binding One-Way Binding Two-Way Binding Model View Model View
5. @sienatime Why is data binding useful?
6. @sienatime Eliminate boilerplate! TextView pokeName = (TextView) findViewById(R.id.poke_name); TextView pokeGenus = (TextView) findViewById(R.id.poke_genus); TextView pokeType = (TextView) findViewById(R.id.poke_type); pokeName.setText(pikachu.name); pokeGenus.setText(String.format(R.string.genus_format, pikachu.genus)); pokeType.setText(pikachu.type) PikachuActivityBinding binding = DataBindingUtil.setContentView(this, R.layout.pikachu_activity); binding.setPikachu(new Pikachu());
7. @sienatime How do I set it up?
8. @sienatime Usage in build.gradle android { dataBinding { enabled = true } } dependencies { compile "com.android.support:appcompat-v7:23.4.0" }
9. @sienatime Usage in XML <layout xmlns:android="http://schemas.android.com/apk/res/android"> <data> <variable name="pikachu" type="net.emojiparty.databindingexample.Pikachu"/> </data> <LinearLayout> <TextView ... android:text="@{pikachu.name}"/> <TextView ... android:text="@{@string/genus_format(pikachu.genus)}"/> <TextView ... android:text="@{pikachu.type}"/> </LinearLayout> </layout>
10. @sienatime Custom @BindingAdapter XML <ImageView ... android:imageResource= "@{pikachu.imageResource}"/> ImageViewBindings.java @BindingAdapter("android:imageResource") public static void setImage(ImageView view, int resourceId) { view.setImageDrawable(view.getContext().getDrawable(resourceId)); } Pikachu.java public int imageResource = R.drawable.sprite_25;
11. @sienatime Data binding works back to API 7! compile "com.android.support:appcompat-v7:23.4.0"
12. @sienatime Further Reading • Code used in this presentation https://github.com/sienatime/pikachu-data- binding • Official documentation https://developer.android.com/topic/libraries/data- binding/index.html • “Data Binding Techniques” by Jacob Tabak’s (video from Droidcon NYC 2015) https://www.youtube.com/watch?v=WdUbXWztKNY • “Marshmallow Brings Data Bindings to Android” by Yiğit Boyar and George Mount (video and transcription from Bay Area Android Dev Group, Oct. 2015) https://realm.io/news/data-binding-android-boyar-mount/ • “Advanced Data Binding” by Yiğit Boyar (video from Google I/O 2016) https: //www.youtube.com/watch?v=DAmMN7m3wLU