Import and export data by odweta · Pull Request #34 · LibreFitOrg/LibreFit

odweta · 2026-04-25T16:20:36Z

Solves #3.

Added the ability to import and export the app's data by extracting and importing the SQLite database.

This feature can be used by interacting with two new buttons at SettingsScreen.

IamDg

Thank you for taking the time to contribute!

While the raw SQL backup implementation is performant, I believe we should move toward a JSON-based architecture for the following reasons:

Raw SQL files are tightly coupled to the database schema, so migrations across different app versions become fragile.
Raw SQL is not human-readable, while JSON is.
Raw imports require a full file-system swap and an app restart (not ideal for UX). JSON allows granular operations (e.g., single workouts) without affecting the entire database.
The current approach only supports overwriting, not merging with the existing DB or other operations.

For these reasons, I think a more robust and idiomatic approach is to use JSON for imports/exports and implement a clear merge strategy.

Let me know what you think!

P.S.: Please merge main before proceeding. Thanks!

odweta · 2026-04-27T08:40:41Z

Hi @IamDg,

Thank you for your suggestions!

I see your point with using a JSON-based architecture for backing up data, as it is more "modular" and allows for more granular control while importing into the database -> fine-grain entity operations instead of overwriting the whole database.

I have a question though about importing a backup made from an old migration into a new version of the app with a DB with a newer migration. Would it cause conflicts? If so, what could be a viable strategy to utilize here?

Also, I have modified strings.xml directly but only for the "default" English translation while the translation guide states that contributors should not modify them directly. I just want to know whether I took the right approach or not.

"Please do not submit Pull Requests for strings.xml files directly, as they will be overwritten by the translation platform sync." [source]

Looking forward to your reply!

IamDg · 2026-04-27T21:30:30Z

I have a question though about importing a backup made from an old migration into a new version of the app with a DB with a newer migration. Would it cause conflicts? If so, what could be a viable strategy to utilize here?

I think the best solution is to include the schema version in the JSON so parsing can be based on that (errors can be handled gracefully). Implement migrations for each schema version and chain them together to be compatible with the current installation.

Also, I have modified strings.xml directly but only for the "default" English translation while the translation guide states that contributors should not modify them directly. I just want to know whether I took the right approach or not.

That warning is for translators who might open a PR on GitHub to submit translations in the base file strings.xml. Source-code contributors may of course modify it.

odweta · 2026-05-03T13:35:39Z

Hey @IamDg,

I have just committed changes that should fulfill your requirements. Exporting now creates a versioned JSON file and importing makes sure the target file is up-to-date on the version, then it upserts the entries into the SQLite DB -- e.g. previously present entries do not get overwritten.

I have tested it on a small sample dataset and both functionalities seem to be working just fine. Though, if you want to, I can try to add some test coverage via unit tests on top of that.

Let me know what you think!

IamDg

Thank you for your work on this feature.

I have reviewed the implementation and would like to suggest some architectural refinements to ensure this feature is robust, maintainable, and aligned with the project's reactive architecture.

Architectural Integrity & Reactive Data Flow

Issue: The current import process uses application-level restarts.
Recommendation: Remove the restart logic.
Reasoning: LibreFit leverages Room and Flow to observe data changes. When the database is updated, the UI layer will automatically reflect those changes. A manual restart provides a poor user experience and is unnecessary. Please rely on standard UI feedback to inform the user that the import is complete.

Introduce Data Transfer Objects (DTOs)

The Issue: It appears the Room entities are being serialized directly.
Recommendation: Introduce explicit Data Transfer Objects (DTOs) for JSON serialization, annotated with @serializable.
Reasoning: Room entities are tied to our database schema. Decoupling them via DTOs ensures that future database changes do not break our user's ability to restore their old backups. It creates a stable "contract" for the export format.

Formalize Schema Versioning

The Issue: The export version is currently hardcoded or managed inconsistently.
Recommendation: Implement an "envelope" structure for the JSON output that includes a schema_version.
Reasoning: As the app grows, our database schema will evolve. A versioned envelope allows us to write "upgrader" functions to transform older JSON structures into the current format during import, ensuring backward compatibility and preventing data loss.

Unified DAO Naming & Responsibilities

The Issue: There is some inconsistency in naming between MeasurementDao and DatasetDao for Flow (reactive) vs suspend (one-shot) methods.
Recommendation: Adopt a consistent naming convention:
Reasoning: This improves code readability and makes the intent of each method immediately clear to other developers.

Enforce Transactional Integrity

The Issue: The addition of generic @upsert methods in WorkoutDao.
Recommendation: I am concerned that these methods bypass our Aggregate Root logic. Please use the existing addWorkoutWithExercisesAndSets transaction method for all Workout-related saves. If the generic methods are not strictly required for the Repository implementation, please remove them to reduce API clutter and prevent accidental data corruption.
Reasoning: The addWorkoutWithExercisesAndSets method handles orphaned record cleanup and transactional consistency. Bypassing it could lead to an inconsistent database state. All Workout-related writes must pass through this transactional gatekeeper.

Serialization Refinement

The Issue: Using @contextual for LocalDateTime.
Recommendation: Please use @serializable(with = LocalDateTimeSerializer::class) explicitly on the data class field.
Reasoning: This is a safer, more explicit approach that doesn't rely on global SerializersModule registration. It makes the code self-documenting and resilient against configuration errors.

The feature is well-started, but we need to ensure it is "future-proofed" against schema changes and adheres to the app's reactive nature. Moving toward an envelope-based versioning system and strictly enforcing the repository-level transaction logic will significantly improve the long-term reliability of this feature.

Please let me know if you have any questions regarding these recommendations. I am happy to discuss the implementation details further!

IamDg · 2026-05-03T17:13:28Z

+
+class ImportExportRepository @Inject constructor(
+    private val db: AppDatabase,
+    @ApplicationContext private val context: Context


Suggested change

@ApplicationContext private val context: Context

@param:ApplicationContext private val context: Context

IamDg · 2026-05-03T17:20:22Z

+            }
+    }
+
+    suspend fun importFrom(uri: Uri) = withContext(Dispatchers.IO) {


Remember to inject the dispatcher ioDispatcher in the constructor marked with param:@IoDispatcher (whichis from DispatcherModule.kt ( https://github.com/LibreFitOrg/LibreFit/blob/main/app/src/main/java/org/librefit/di/DispatcherModule.kt#L27 )

Suggested change

suspend fun importFrom(uri: Uri) = withContext(Dispatchers.IO) {

suspend fun importFrom(uri: Uri) = withContext(ioDispatcher) {

IamDg · 2026-05-03T17:26:01Z

 material = { group = "com.google.android.material", name = "material", version.ref = "material" }
 coil = { group = "io.coil-kt.coil3", name = "coil-compose", version.ref = "coil" }
 reorderable = { module = "sh.calvin.reorderable:reorderable", version.ref = "reorderable" }
+androidx-compose-foundation-layout = { group = "androidx.compose.foundation", name = "foundation-layout", version.ref = "foundationLayout" }


See above

Suggested change

androidx-compose-foundation-layout = { group = "androidx.compose.foundation", name = "foundation-layout", version.ref = "foundationLayout" }

IamDg · 2026-05-03T17:26:14Z

 material = "1.14.0-beta01"
 coil = "3.4.0"
 reorderable = "3.1.0"
+foundationLayout = "1.11.0"


See above

Suggested change

foundationLayout = "1.11.0"

IamDg · 2026-05-03T17:26:42Z


 dependencies {

+    implementation(libs.androidx.compose.foundation.layout)


Why this is added? It is redundant because it's already included in implementation(platform(libs.androidx.compose.bom))

Suggested change

implementation(libs.androidx.compose.foundation.layout)

IamDg · 2026-05-03T18:00:57Z

    fun getAllMeasurements(): Flow<List<Measurement>>

+    @Query("SELECT * FROM measurements ORDER BY date DESC")
+    suspend fun getAllMeasurementsForBackup(): List<Measurement>


Use standard naming conventions

Suggested change

suspend fun getAllMeasurementsForBackup(): List<Measurement>

suspend fun getAllMeasurementsOnce(): List<Measurement>

IamDg · 2026-05-03T18:01:43Z

    fun getDataset(): Flow<List<ExerciseDC>>

+    @Query("SELECT * FROM dataset ORDER BY name")
+    suspend fun getAllExerciseDCs(): List<ExerciseDC>


Use standard naming conventions

Suggested change

suspend fun getAllExerciseDCs(): List<ExerciseDC>

suspend fun getDatasetOnce(): List<ExerciseDC>

IamDg · 2026-05-03T18:09:31Z

    @get:FloatRange(0.0, 300.0) val bodyWeight: Double = 0.0,
    @get:IntRange(0, 100) val bodyFatPercentage: Int = 0,
    @get:IntRange(0, 100) val muscleMassPercentage: Int = 0,
+    @Contextual


Use this serializer LocalDateTimeSerializer ( https://github.com/LibreFitOrg/LibreFit/blob/main/app/src/main/java/org/librefit/db/entity/LocalDateTimeSerializer.kt ) instead:

Suggested change

@Contextual

@Serializable(with = LocalDateTimeSerializer::class)

odweta · 2026-05-09T13:50:55Z

Sorry, I accidentally deleted the branch and that closed this PR. I reopened it.

odweta · 2026-05-09T13:52:49Z

Thank you for the patience with me on this one.

I believe I have followed through and implemented your suggestions. The export and import processes emit events now and simple snackbars are shown to signal the results. The app now does not restart and utilizes Flows and observing them.

Let me know your stance on this!

IamDg

Hi,

Sorry for late reply!

Firstly, I'd suggest you to merge conflicts with main branch before proceding further in order to avoid work later.
Secondly, the PR itself is much better than previous iteration but it needs major corrections/improvements.

Thank you for taking the time to contribute!

odweta · 2026-06-01T18:43:12Z

Hi,

I resolved all of your open conversations, please let me know if the current state of my changes is up to the app's standards now.

Thanks, looking forward to your review!

odweta added 2 commits April 25, 2026 15:53

add: import & export buttons in SettingsScreen

760813f

update: add import and export functionality

c17da6d

IamDg self-requested a review April 26, 2026 16:09

IamDg requested changes Apr 26, 2026

View reviewed changes

IamDg added enhancement New feature or request good first issue Good for newcomers labels Apr 27, 2026

IamDg mentioned this pull request Apr 29, 2026

Micro Ai (locally, 0.6B?!?) to build the right program for the athlete #38

Closed

3 tasks

odweta added 3 commits April 30, 2026 09:22

progress on a migration from raw SQL backup/restore to a JSON arch.

daed80b

update: JSON data export/import

1d61653

fix: remove temporary logging

e8bb260

IamDg requested changes May 3, 2026

View reviewed changes

IamDg linked an issue May 3, 2026 that may be closed by this pull request

Import and export data #3

Open

odweta added 12 commits May 9, 2026 11:05

fix: remove to-be-deprecated content

8e2aed6

fix: proper use of ioDispatcher

3bc0c36

fix: remove unused imports

a6b6f97

fix: remove redundant lib in libs.versions.toml

eb46859

fix: repair build.gradle.kts

f1ee9b5

fix: use standard naming conventions

70c7dc0

fix: use correct serializer for LocalDateTime

cab0cc9

fix: remove unused variables

aab175e

fix: revert prev commit

703cfb7

fix: remove unnecessary upsert methods

3d0f7aa

fix: correct export/import pipeline (but allows duplicates)

3ecf5e0

fix: convert toasts to snackbars

e7f57bc

odweta closed this May 9, 2026

odweta deleted the feat/import-and-export-data branch May 9, 2026 13:48

odweta restored the feat/import-and-export-data branch May 9, 2026 13:49

odweta reopened this May 9, 2026

IamDg requested changes May 23, 2026

View reviewed changes

odweta added 9 commits May 25, 2026 11:31

resolve merge conflicts with upstream

0d1f0c6

add: missing generic savePreferences function

7d6d1cf

add: datastore dependency

3988156

fix: correct jvm version

2240b70

update: use dialogs instead of snackbars

67efb57

fix: fix linted errors

d7000c9

fix: add proper migration logic

29d6a42

fix: fix typo and add animations to loading

01a3c42

fix: separated concerns regarding SettingsEvents

edb8a62

IamDg reviewed May 29, 2026

View reviewed changes

Comment thread gradle/libs.versions.toml Outdated

fix: remove redundant datastore dependency

48d9855

odweta requested a review from IamDg June 1, 2026 18:49

	@ApplicationContext private val context: Context
	@param:ApplicationContext private val context: Context

	suspend fun importFrom(uri: Uri) = withContext(Dispatchers.IO) {
	suspend fun importFrom(uri: Uri) = withContext(ioDispatcher) {


		dependencies {

		implementation(libs.androidx.compose.foundation.layout)

	suspend fun getAllMeasurementsForBackup(): List<Measurement>
	suspend fun getAllMeasurementsOnce(): List<Measurement>

	suspend fun getAllExerciseDCs(): List<ExerciseDC>
	suspend fun getDatasetOnce(): List<ExerciseDC>

	@Contextual
	@Serializable(with = LocalDateTimeSerializer::class)

Conversation

odweta commented Apr 25, 2026

Uh oh!

IamDg left a comment

Choose a reason for hiding this comment

Uh oh!

odweta commented Apr 27, 2026

Uh oh!

IamDg commented Apr 27, 2026

Uh oh!

odweta commented May 3, 2026

Uh oh!

IamDg left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

odweta commented May 9, 2026

Uh oh!

odweta commented May 9, 2026

Uh oh!

IamDg left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

odweta commented Jun 1, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

odweta commented Jun 1, 2026 •

edited

Loading