objectbox/objectbox-java

Improve DataObserver reference holding

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#215 opened on Oct 16, 2017

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enhancementhelp wanted

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Description

I'm trying to use obervable queries to detect when the user is logged in my application in order to start fetching data in background with correct authorization token.

    ...
    userBox.query().build().subscribe().observe(users -> fetchUserData());
    ...
    boxStore.subscribe(User.class).observe(class -> fetchUserData());

First "live" query doesn't work whilst the second works fine whenever I put(user) a new user in the userBox.

Is this correct? I'm not sure from which thread the user is being inserted, might this be an issue? Does it make sense to use a "live" query to observe the insertion of new objects or is it just for changes in existing objects? Live queries would be great, for my application and are the main feature that made me pick ObjectBox, hope I can get it working.

Contributor guide

Research direction
Inspect the DataObserver lifecycle and its reference management. Trace the subscription code for boxStore.query() vs boxStore.subscribe() to identify why the former does not emit on new inserts.
Tech stack
java
Domain
databasemobile
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaGit
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60