Usage of parceler (@Parcel) with Realm.io (Android)

[sam-ghosh]

I have the following code which produces the error: Error:Parceler: Unable to find read/write generator for type io.realm.Realm for io.realm.RealmObject.realm

It was working all fine without extends RealmObject , however I want to use Realm to put to database easily. Is there a way to exlcude the RealmObject fields and just use the basic pojo fields for @parcel?

    @Parcel
    public class Feed extends RealmObject{
        int id;
        public String text;
        public String time_created;
        String time_modified;
        int comments_count;
        int likes_count;
        String feed_type;
        int obj_id;
        String image;
        String user_name;
        String user_earthmile_points;
        boolean liked;
        boolean commented;
        boolean is_private;
        String url;
        int feed_creator_id;
  }

[johncarl81]

I have not looked into Realm deeply, but I'm disappointed to see it introduces a base class that you have to extend.

There's a couple of options here:

First, you could define a ParcelConverter that gives you the ability to define serialization manually.
Second, we (@loganj) have discussed adding a scan-limit to the processor which would allow you to tell the processor to stop and not process RealmObject or deeper. It seems that this would be the use case for such a feature.

Third, could you define your RealmObject as a wrapper instead (again, I'm nearly completely ignorant on Realm)?:

public class FeedRealmObject extends RealmObject {
    Feed feed;
}

@Parcel
public class Feed {
    //...
}

[johncarl81]

I figured I'd go ahead and implement the scan limit (#59) since it was a natural next step. I've also pushed this to 0.2.16-SNAPSHOT if you'd like to try it out.

[sam-ghosh]

Thanks, should it be in the Maven repo? What should i put in my build.girdle instead of
compile 'org.parceler:parceler:0.2.15'

Many thanks

[johncarl81]

You need to add the maven central snapshots repo:

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

And update the parceler dependency to:

compile 'org.parceler:parceler-api:0.2.16-SNAPSHOT'
provided 'org.parceler:parceler:0.2.16-SNAPSHOT'

Keep in mind that SNAPSHOTS are volatile... without notice I may redact the current functionality. That being said, give it a try and let me know if it works for you.

[sam-ghosh]

Thanks, i got an error saying:
Error:Could not find org.parceler:parceler-api:0.2.16-SNAPSHOT.
Required by:
TestAndroid:app:unspecified

[sam-ghosh]

Thanks, I found my mistake here : http://stackoverflow.com/questions/20574111/add-maven-repository-to-build-gradle

[sam-ghosh]

Due to constraints with Realm, I need to put variables as public, while Parceler wants private (for speed)

So I need to do :

    @Parcel(analysisLimit = RealObject.class, Parcel.Serialization.METHOD )

is this the right syntax inside the bracket?

Thanks again

[johncarl81]

Looks about right:

@Parcel(value = Parcel.Serialization.METHOD, analysisLimit = RealmObject.class)

I'm not sure what you mean by Parceler wants private. Parceler will warn you that it will use reflection if using the Serialization.FIELD technique and it finds private fields. Can you clarify?

[sam-ghosh]

Apologies, I meant Realm.io wants the class properties to be private (and having getter/setter), while if I put private properties without Serialization.METHOD, Parceler won't accept. hence I need to put both the arguments inside the brackets for both packages (parceler, realm) to work

[johncarl81]

Oh OK, yes, Serialization.METHOD will follow the private fields & getter/setter Java Bean standard.

[johncarl81]

By the way, I think I'm going to change the name of this Serialization technique to Serialization.BEAN to better represent what standard it follows. Any thoughts on this? (#60)

[johncarl81]

@somghosh, how did this work out for you?

[sam-ghosh]

Thanks a lot @johncarl81 . I used it and it worked out from the Parceler point of view (meaning that the parcelling method stopped at the specified limit). So it works for simple Realm objects.

However, the JSON string I get from sever is as a compound Pojo (class inside a class) and hence things did not work from the Realm point of view. I would still encourage you to put this up as a revision, as for simple objects, Parceler can be used with Realm now.

Many thanks

[johncarl81]

Thinking about this more, we could do something like specify exactly what classes are analyzed, like so:

@Parcel(value = Parcel.Serialization.METHOD, analyze = {One.class, Three.class)
class One extends Two{}
class Two extends Three{}
class Three extends BaseClass{}

Which would offer even more flexability. What do you think @somghosh?

[ppamorim]

+1, not working with ActiveAndroid too.

[sam-ghosh]

@johncarl81 I think that would solve the problem. Many thanks

[ppamorim]

@somghosh not working with snapshot, analysisLimit doesn't exist.

[johncarl81]

@ppamorim, I've been working on another branch that I pushed out to maven central. You can still get to this feature by building the limit_analysis branch on your own (#59).

[dracek]

@ppamorim I've tried 0.2.16-SNAPSHOT with ActiveAndroid 3.1.0-SNAPSHOT (and Retrofit) and it seems working flawless so far.

@Parcel(value = Parcel.Serialization.BEAN, analysisLimit = SMS.class)
@Table(name = "SMS")
public class SMS extends Model {
    @SerializedName("id")
    @Column(name = "smsid", index = true, unique = true, onUniqueConflict = Column.ConflictAction.FAIL)
    String id;
    // etc.
}

@johncarl81 many thanks for your work! I really appreciate it!

[johncarl81]

@ppamorim, @dracek, @ppamorim Any thoughts on a more specific approach mentioned above:

@Parcel(value = Parcel.Serialization.METHOD, analyze = {One.class, Three.class)
class One extends Two{}
class Two extends Three{}
class Three extends BaseClass{}

^ Where only The One and Three class would be analyzed. This allows much more control and variability to the property with the drawback of being more verbose.

[johncarl81]

This is implemented and deployed in version 0.2.16.

[ppamorim]

@johncarl81 Doc it.

[vickychijwani]

Thanks a lot for fixing this, @johncarl81!

[vickychijwani]

EDIT: please ignore this comment, do what @johncarl81 says in his comment below, i.e.,:

• Use Parcels.wrap(MyObj.class, obj) instead of Parcels.wrap(obj), OR
• Annotate your class as @Parcel(implementations={ MyObjRealmProxy.class }) (this would require you to make MyObjRealmProxy visible to the IDE by adding the android-apt plugin as below or adding the generated proxy class manually to your IDE sources)

---

For anyone actually looking to use Parceler with Realm, there's a couple more steps needed:

• Add the android-apt plugin to your build.gradle, so that the generated Parcelable class is visible to Android Studio.

buildscript {
    repositories {
      mavenCentral()
    }
    dependencies {
        // replace with the current version of the Android plugin
        classpath 'com.android.tools.build:gradle:0.14.4'
        // use the latest version, see http://gradleplease.appspot.com/#android-apt
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.4'
    }
}

apply plugin: 'com.android.application'
apply plugin: 'com.neenbedankt.android-apt'

• Use new MyObj$$Parcelable(obj) instead of Parcels.wrap(obj), otherwise your app will crash with org.parceler.ParcelerRuntimeException: Unable to create ParcelableFactory for io.realm.MyObjRealmProxy. You can still use Parcels.unwrap(...) on the other side.

[johncarl81]

@vickychijwani, does it work to specify the class type instead of referencing the generated class:
Parcels.wrap(Feed.class, obj)

[vickychijwani]

Yes, it works! Can you explain what causes the error if I call the single parameter version of Parcels.wrap(...)? Thanks!

[johncarl81]

Parcels.wrap() looks up your instance against a map of ParcelableFactorys by calling .getClass(). The downside of this is it ignores inheritance, so if your class is proxied (like I assume MyObjRealProxy is), then Parceler doesn't know what to do.

worth noting, another way to handle this is add yoru proxy class to the implementations parameter:

@Parcel(implementations={MyObjRealProxy.class})

This will add your proxy class to the Parcels wrap mappings.

[johncarl81]

@ppamorim Documented here:
https://github.com/johncarl81/parceler#advanced-configuration
http://parceler.org/#advanced_configuration

[rolandvar]

I'm trying to use Parceler (1.0.2) and Active Android (3.0.1-SNAPSHOT), but there is something wrong!

I have the following code which produces the error: org.parceler.ParcelerRuntimeException: Unable to find generated Parcelable class for com.mywebsitetest.android.model.Playlist, verify that your class is configured properly and that the Parcelable class com.mywebsitetest.android.model.Playlist$$Parcelable is generated by Parceler.

@Table(name = "Playlists")
@Parcel(value = Parcel.Serialization.BEAN, analyze = Playlist.class)
public class Playlist extends Model {

    @SerializedName("RemoteId")
    @Column(name = "RemoteId")
    private int remoreId;

    @SerializedName("Token")
    @Column(name = "Token", index = true)
    private String token = "defaultToken";

    @SerializedName("User")
    @Column(name = "User", onDelete = Column.ForeignKeyAction.CASCADE)
    private User user;

    @SerializedName("Name")
    @Column(name = "Name")
    private String name;

    @SerializedName("Create")
    @Column(name = "Created")
    private long created;

    @SerializedName("Updated")
    @Column(name = "Updated")
    private long updated;

    public Playlist() {
        super();
    }

....

And in the Main.java I have:

...

Parcelable playlistParcelable = Parcels.wrap(playlist);

...

I also tried it in this way:

...

Parcelable playlistParcelable = Parcels.wrap(Playlist.class, playlist);

...

but still it does not work, someone knows why?

[johncarl81]

Can you share your build?

[rolandvar]

Sure!

In the gradle console I also have the follow error:

build.gradle (Module: app)

apply plugin: 'com.android.application'
apply plugin: 'com.neenbedankt.android-apt'

android {
    compileSdkVersion 22
    buildToolsVersion "22.0.1"

    defaultConfig {
        applicationId "com.mywebsitetest.android"
        minSdkVersion 18
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

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

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.2.0'
    compile 'it.neokree:MaterialTabs:0.11'
    compile 'de.greenrobot:eventbus:2.4.0'
    compile 'com.squareup.retrofit:retrofit:1.9.0'

    compile 'com.michaelpardo:activeandroid:3.1.0-SNAPSHOT'

    compile "org.parceler:parceler-api:1.0.2"
    apt "org.parceler:parceler:1.0.2"
}

build.gradle (Project)

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.2.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
        // replace with the current version of the Android plugin
        // use the latest version, see http://gradleplease.appspot.com/#android-apt
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.4'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

Thanks for your help!

[johncarl81]

Ah, it looks like there's an error during compilation. From your screenshot:

Unable to find read/write generator for type com.activeandroid.TableInfo for com.activeandroid.Model.mTableInfo

Trying your code out on my test bench, it seems to work properly. What does User look like? Does User also extend Model?

[ppamorim]

@johncarl81 Same here :(

[johncarl81]

@ppamorim, @Makingweb, can you offer any more details around this?

[evasquezcr]

@johncarl81 I'm working with Realm and I got this error,
'Error:Parceler: Unable to find read/write generator for type io.realm.Realm for io.realm.RealmObject.realm
Error:Parceler: Unable to find read/write generator for type io.realm.internal.Row for io.realm.RealmObject.row
Error:Parceler: Unable to find read/write generator for type io.realm.Realm for io.realm.RealmObject.realm
Error:Parceler: Unable to find read/write generator for type io.realm.internal.Row for io.realm.RealmObject.row'

Do you know if I can change something to make it works?

[johncarl81]

@evasquezcr, you'll need to specify what classes Parceler should analyze, to avoid analyzing the RealmObject base class. People also have had success by specifying the Realm Proxy object in the implementations configuration. Example:

@Parcel(implementations = { PersonRealmProxy.class }, 
        value = Parcel.Serialization.BEAN, 
        analyze = { Person.class })
public class Person extends RealmObject {
    // ...
}

See https://realm.io/docs/java/latest/#parceler for details.

[hunain-liaquat]

HI,
How we can have refrence to Proxy class ?

[johncarl81]

What do you mean @hunain-liaquat?

[hunain-liaquat]

Issue resolved, I didn't find reference to BirthdayRealmProxy.class but found in io.realm package after build successfully compiled once.