a simple-ish json question

[Johnny TwoShoes]

Hello,

If I have two sets of data:

{"event_id":"20872","event_action":"update","event_data”:[{“a”:”1”,”b”:”1”}],"event_type”:”typea”}

{"event_id":"20873”,”event_action":"update","event_data”:[{“x”:”1”,”y”:”1”,,”z”:”1”}],”event_type”:”typeb”}

Where type a and type b, are unrelated, how do I model this in realm?

kind regards

[Kenneth Geisshirt]

Hey Johnny,

The model would be simple without the "type a and type b are unrelated". You will probably have to to:

class Event extends RealmObject {
private long event_id;
private String event_action;
private RealmList<EventData> event_data;
private EventType event_type;
}

class EventData extends RealmObject {
private String key;
private long value;
}

class EventType extends RealmObject {
private boolean typea_or_typeb;
private TypeA typea;
private TypeB typeb;
}

class TypeA extends RealmObject {
// fields
}

class TypeB extends RealmObject {
// fields
}

Best,
Kenneth

--
Kenneth Geisshirt
Member of technical staff

{#HS:159019920-2623#}

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[Johnny TwoShoes]

Hi Kenneth,

Thanks. What I was hoping for, was, if I could put something in the Event constructor, so that I could either json sets of data, through, gson, and it will automatically populate the objects?

Is that possible?

kind regards

[Kenneth Geisshirt]

Hi Johnny,

You can change the Event class to

class Event extends RealmObject {
private long event_id;
private String event_action;
private RealmList<EventData> event_data;

private boolean typea_or_typeb;
private TypeA typea;
private TypeB typeb;
}

and populate the object first as a plain Java object and use Realm.copyToRealm().

Said that, we are exploring various option on how to implement inheritance which might be useful in your case. See https://github.com/realm/realm-java/issues/761.

Best,
Kenneth

--
Kenneth Geisshirt
Member of technical staff

{#HS:159019920-2623#}

[Johnny TwoShoes]

Hi,

Thanks for your advice. I managed to get it to do what I wanted , eg a simple interface to convert the json into pojo's without extra coding, but, I resorted to a quick small regex hack, to reformat the json string, before converting it. It does the job, but, there is probably a more elegant solution out there.

So:

realm.createObjectFromJson(EventsOut.class, convertStr(loadJSONFromAsset(filename))); //works for all values

and model EventsOut has:

    private RealmList<TypeA> typeas;

    private RealmList<TypeB> typebs;

So, the hack is in the convertStr, which uses regex, to reshuffle the value of type, and replace the EventsData text with it.

So,

{"event_id":"20872","event_action":"update","event_data”:[{“a”:”1”,”b”:”1”}],"event_type”:”typea”}

becomes

{"event_id":"20872","event_action":"update","typea”:[{“a”:”1”,”b”:”1”}],"event_type”:”typea”} 

and

{"event_id":"20873”,”event_action":"update","event_data”:[{“x”:”1”,”y”:”1”,,”z”:”1”}],”event_type”:”typeb”}

becomes

{"event_id":"20873”,”event_action":"update","typeb”:[{“x”:”1”,”y”:”1”,,”z”:”1”}],”event_type”:”typeb”}

it then works. It's not very elegant, but, it saves alot of if then code, especially, if I have alot of different types.

But, I will look into your solution, maybe it's better.

kind regards