Possible to go from auto-value object back to a cursor via ContentValues? about auto-value-cursor

[rharter]

The idea of a ContentValuesBuilder might be simplified by simply adding a toContentValues() method to the generated class, so you could use it like this:

ContentValues values = User.builder()
  .id(id)
  .name(name)
  .email(email)
  .build()
  .toContentValues();

The @ContentValuesBuilder seems inflexible in that the user would have to add both Builder and ContentValuesBuilder inner classes in order to use it. I wonder if the auto-value-cursor generated class could simply override the $AutoValue_User.Builder class to add a public ContentValues asContentValues() method so that, if the class has an @AutoValue.Builder inner class, the ContentValues addition can be added with no extra code.

My suspicion is the the extension support in AutoValue will have to be extended to the Builder in order to accommodate this type of functionality.

[gabrielittner]

I'll add support for that, but I'm currently a bit busy. Maybe this or next weekend. If you want to give it a try before that I'm happy about pull requests 😃

[laurencedawson]

Can confirm this is working great. Thanks again for your help.

[gabrielittner]

Yes it is possible.

It would even be possible to generate a ContentValues Builder class similar AutoValue Builders for ContentValues. Something like this:

@AutoValue public abstract class User {
  abstract String id();
  abstract String name();
  abstract String email();

  @ContentValuesBuilder
  abstract static class ContentValuesBuilder {
    abstract ContentValuesBuilder id(String id);
    abstract ContentValuesBuilder name(String name);
    abstract ContentValuesBuilder email(String email);
    abstract ContentValues build();
  }

  // returns ContentValuesBuilder with values from current object
  abstract ContentValuesBuilder toContentValuesBuilder();

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

[rharter]

Re: the toContentValues method, you could simply check the class for an abstract method returning ContentValues, and implement that to convert the class to ContentValues and return it.

[gabrielittner]

Yeah a regular toContentValues() should definitely be done and is super easy to implement.
I just thought that it might be nice to have the ContentValuesBuilder on top of that. One major advantage of having it would be that you can use it for partial updates like only updating name and email. That would only work with either a separate Builder or extending the default Builder, because build().toContentValues() would do null checks.

[gabrielittner]

@laurencedawson The latest 0.3.0-SNAPSHOT will now generate a toContentValues() if you add an abstract one to your class.

[laurencedawson]

@gabrielittner Fantastic thanks!

[laurencedawson]

@gabrielittner sorry but can you provide a quick example? Thanks

[gabrielittner]

You just need to change the dependency to the snapshot version and add public abstract ContentValues toContentValues() to your AutoValue class.

[laurencedawson]

Have you published the snapshot or do you mean built it and add locally?

[gabrielittner]

Snapshots are published to a different repository. You have to add

maven {
    url "https://oss.sonatype.org/content/repositories/snapshots"
}

to the repositories block in your build.gradle file.

[laurencedawson]

Aha thanks!

[laurencedawson]

I created another issue but I think it's probably best discussed in here.

If a custom class is defined and setup with the @CursorAdapter annotation, the toContentValues method will cause the build to fail throwing the following error message:

Error:Property "Y" has type "X" that can't be put into ContentValues

Would it be possible to add along side the CursorAdapterFactory (containing createFromCursor) a method to saveToCursorValues?

Thanks