AutoValue: Cursor Extension

An extension for Google's AutoValue that generates a createFromCursor(Cursor c) method for AutoValue annotated objects.

Usage

Include auto-value-cursor in your project and add a static factory method to your auto-value object.

import com.gabrielittner.auto.value.cursor.ColumnName;

@AutoValue public abstract class User {
  abstract String id();
  abstract String name();
  // use the annotation if column name and field name aren't the same
  @ColumnName("email_address") abstract String email();

  public static User create(Cursor cursor) {
    return AutoValue_User.createFromCursor(cursor);
  }

  // Optional: if your project includes RxJava the extension will generate a Func1<Cursor, User>
  public static Func1<Cursor, User> MAPPER = AutoValue_User.MAPPER;

  // Optional: if your project includes RxJava 2 the extension will generate a Function<Cursor, User>
  public static Function<Cursor, User> MAPPER = AutoValue_User.MAPPER_FUNCTION;

  // Optional: When you include an abstract method that returns ContentValues and doesn't have
  // any parameters the extension will implement it for you
  abstract ContentValues toContentValues();
}

Important: The extension will only be applied when there is

• a static method that returns your value type (User in the example) and takes a Cursor as parameter
• and/or a static field of type Func1<Cursor, YourValueType>
• and/or a static field of type Function<Cursor, YourValueType>

Custom types

The following types are supported by default:

• byte[]
• double/Double
• float/Float
• int/Integer
• long/Long
• short/Short
• String
• boolean/Boolean

For other types, you need to use the @ColumnAdapter annotation and specify a factory class that implements the ColumnTypeAdapter interface. When you need to map multiple columns to one custom type you can simply ignore the given columnName. Eg.:

User.java:

@AutoValue public abstract class User {
  abstract String id();
  abstract String name();
  @ColumnAdapter(AvatarAdapter.class) Avatar avatar();

  public static User createFromCursor(Cursor cursor) {
    return AutoValue_User.createFromCursor(cursor);
  }
}

AvatarAdapter.java:

public class AvatarAdapter implements ColumnTypeAdapter<Avatar> {
  public Avatar fromCursor(Cursor cursor, String columnName) {
    String smallImageUrl = cursor.getString(cursor.getColumnIndex("small_image_url");
    String largeImageUrl = cursor.getString(cursor.getColumnIndex("large_image_url");
    return new Avatar(smallImageUrl, largeImageUrl);
  }
  public void toContentValues(ContentValues values, String columnName, Avatar value) {
    // leave this empty when you don't use a "toContentValues()" method
    values.putString("small_image_url", value.smallImageUrl);
    values.putString"large_image_url", value.largeImageUrl);
  }
}

Avatar.java:

public class Avatar {
  final String smallImageUrl;
  final String largeImageUrl;

  public Avatar(String smallImageUrl, String largeImageUrl) {
    this.smallImageUrl = smallImageUrl;
    this.largeImageUrl = largeImageUrl;
  }
}

Download

Add a Gradle dependency:

annotationProcessor 'com.gabrielittner.auto.value:auto-value-cursor:2.0.1'
// if you need the @ColumnName or @ColumnAdapter annotations also include this:
implementation 'com.gabrielittner.auto.value:auto-value-cursor-annotations:2.0.1'

Snapshots of the development version are available in Sonatype's snapshots repository.

License

This project is heavily based on Ryan Harter's auto-value-gson

Copyright 2015 Ryan Harter.
Copyright 2015 Gabriel Ittner.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.