comparable_version_sync 1.2.0

Compare and merge JSON or SQLite versions with a configurable Flutter diff/merge widget.

comparable_version_sync

A Flutter package for comparing and merging versions of JSON or SQLite data with a fully configurable, git-conflict-style diff/merge widget.

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Demostration

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Features

• Two display modes — raw paginated view or per-field diff view.
• Two file types — JSON (any Map/List root) or SQLite (multi-table).
• Git-style merge resolution — Accept Local, Accept Incoming, or Manual Edit per field.
• Auto-accept compatible diffs — one-tap to accept all fields where only one side has a value.
• Side-by-side diff detail — read-only view of the parent JSON context with highlights.
• Synchronized scroll — both panels scroll together vertically; independent horizontal scroll per panel.
• Resizable split panel — drag the divider in the diff detail screen to adjust the panel ratio.
• Responsive layout — automatically switches between side-by-side and tabbed layout based on screen width.
• Fully configurable — every dimension, colour, and animation parameter is exposed via ComparableVersionTheme.
• Lazy loading — only the current page ±1 is kept in memory; safe for large files.

---

Installation

Add to your pubspec.yaml:

dependencies:
  comparable_version_sync: ^1.1.0

Then run:

flutter pub get

---

Quick Start

import 'package:comparable_version_sync/comparable_version_sync.dart';

// Diff view from in-memory JSON (no file I/O inside the package)
ComparableVersionWidget.diffViewFromJson(
  jsonA: jsonDecode(jsonStringA),   // or a Map/List you already have
  jsonB: jsonDecode(jsonStringB),
  comparisonMode: ComparisonMode.allDiffs,
  diffsPerPage: 10,
  displayWidget: (diff) => Text(
    'A: ${diff.valueA}  →  B: ${diff.valueB}',
    style: const TextStyle(fontSize: 12, color: Colors.black54),
    overflow: TextOverflow.ellipsis,
  ),
  returnType: ReturnType.json,
  onMergeComplete: (result) {
    print(result.mergedJson); // your merged data
  },
)

---

Display Modes

ComparableVersionWidget.diffViewFromJson

Shows every detected difference as a tappable tile. Tapping opens a full-screen merge overlay where the user picks Local, Incoming, or types a custom value. A "Finalize" FAB collects all choices and calls onMergeComplete.

ComparableVersionWidget.diffViewFromJson(
  jsonA: jsonA,
  jsonB: jsonB,
  comparisonMode: ComparisonMode.allDiffs,
  diffsPerPage: 10,
  displayWidget: (diff) => Text('${diff.valueA} → ${diff.valueB}'),
  // Optional: custom content above the choice cards in the merge overlay
  mergeWidget: (diff) => MyCustomDiffSummary(diff: diff),
  // Optional features
  showAcceptCompatibleButton: true,
  acceptCompatibleByDefault: true,
  showDiffDetailButton: true,
  returnType: ReturnType.json,
  onMergeComplete: (result) => handleMerge(result),
)

ComparableVersionWidget.rawViewFromJson

Shows the raw JSON records from both in-memory structures side-by-side (or in a tab view on narrow screens), paginated. No per-field resolution — "Accept File 1" FAB immediately returns the left side as the winner.

ComparableVersionWidget.rawViewFromJson(
  jsonA: jsonA,
  jsonB: jsonB,
  recordsPerPage: 10,
  returnType: ReturnType.json,
  onMergeComplete: (result) => handleMerge(result),
)

ComparableVersionWidget.diffView and .rawView (file-based)

For apps that prefer to pass file paths (JSON or SQLite), the original constructors are still available:

ComparableVersionWidget.diffView(
  fileType: FileType.json,
  file1Path: path1,
  file2Path: path2,
  comparisonMode: ComparisonMode.incompatibleOnly,
  diffsPerPage: 10,
  returnType: ReturnType.json,
  onMergeComplete: (result) => handleMerge(result),
)

---

API Reference

ComparableVersionWidget

Shared parameters (all constructors)

Parameter	Type	Default	Description
comparisonMode	ComparisonMode	— required	allDiffs or incompatibleOnly
returnType	ReturnType	— required	json, sql, or both
onMergeComplete	void Function(MergeResult)	— required	Called with the merge result
theme	ComparableVersionTheme	ComparableVersionTheme()	Visual configuration

diffViewFromJson only

Parameter	Type	Default	Description
diffsPerPage	int	10	Diffs shown per page
displayWidget	Widget Function(DiffContext)	— required	Summary row renderer
mergeWidget	Widget Function(DiffContext)?	null	Custom content above choice cards
showAcceptCompatibleButton	bool	false	Show auto-accept toggle chip
acceptCompatibleByDefault	bool	true	Pre-accept compatible diffs on load
showDiffDetailButton	bool	false	Show "View Raw Diff" button in overlay
diffDetailButtonAlignment	Alignment	Alignment.topRight	Placement of the raw diff button
toJsonConverter	String Function(dynamic)?	null	Fallback serialiser for custom types

rawViewFromJson only

Parameter	Type	Default	Description
recordsPerPage	int	10	Records shown per page

File-based constructors (diffView / rawView)

These legacy constructors accept file paths and a FileType (JSON/SQLite). On JSON, they may use platform-specific I/O; on SQLite they use sqflite / FFI factories to open the databases.

---

ComparisonMode

Value	Behaviour
ComparisonMode.allDiffs	Every field that differs between the two files
ComparisonMode.incompatibleOnly	Only true conflicts — both sides non-null and different. Fields where one side is absent or null are skipped.

---

ReturnType

Value	MergeResult fields populated
ReturnType.json	mergedJson
ReturnType.sql	mergedRows
ReturnType.both	Both mergedJson and mergedRows

---

DiffContext

Passed to displayWidget, mergeWidget, and onMergeComplete callbacks.

Field	Type	Description
path	String	Dot-notation path to the differing field (e.g. "user.address.city")
parentContext	String	Dot-notation path of the smallest shared parent
valueA	dynamic	Value from file 1 (null if absent)
valueB	dynamic	Value from file 2 (null if absent)
isCompatible	bool	true when only one side is non-null (no true conflict)
parentValueA	dynamic	Full parent JSON subtree from file 1
parentValueB	dynamic	Full parent JSON subtree from file 2

---

MergeResult

Field	Type	Description
mergedJson	Map<String, dynamic>?	Merged JSON structure; null when returnType == ReturnType.sql
mergedRows	List<Map<String, dynamic>>?	Merged rows; null when returnType == ReturnType.json

---

Theming

ComparableVersionTheme exposes every visual knob as a named parameter. All parameters are optional and have sensible defaults.

const myTheme = ComparableVersionTheme(
  // Panel split
  initialSplitRatio: 0.4,       // left panel starts at 40 %
  minSplitRatio: 0.15,
  maxSplitRatio: 0.85,
  dividerWidth: 8.0,

  // Code lines
  lineHeight: 22.0,
  linePadding: 10.0,
  codeCanvasWidth: 3000.0,      // increase for very deeply-indented JSON

  // Horizontal pan bar
  panBarHeight: 28.0,
  panBarHandleWidth: 56.0,
  panBarHandleHeight: 5.0,

  // Highlight colours (ARGB)
  localHighlightColor: Color(0x2200BCD4),     // cyan tint for local
  incomingHighlightColor: Color(0x22FF5722),  // deep-orange tint for incoming

  // Scroll animation
  scrollAnimationDuration: Duration(milliseconds: 200),
  scrollAnimationCurve: Curves.easeInOut,

  // Layout
  responsiveBreakpoint: 720.0,  // wider breakpoint for the raw view

  // Cards
  cardBorderRadius: 16.0,
  cardPadding: 14.0,
  selectedBorderWidth: 2.5,
  cardAnimationDuration: Duration(milliseconds: 120),

  // Icons & text
  iconSize: 22.0,
  smallIconSize: 20.0,
  monoFontSize: 14.0,
  smallLabelFontSize: 12.0,

  // FAB offsets
  fabBottomOffset: 24.0,
  fabRightOffset: 24.0,
  diffFabBottomOffset: 80.0,
  diffFabRightOffset: 24.0,
  listBottomPadding: 90.0,
  overlayBodyBottomPadding: 110.0,
);

ComparableVersionWidget.diffView(
  theme: myTheme,
  ...
)

Use copyWith to derive a variant from the defaults:

final compactTheme = const ComparableVersionTheme().copyWith(
  lineHeight: 16,
  panBarHeight: 18,
  monoFontSize: 11,
);

Full ComparableVersionTheme parameter reference

DiffDetailScreen — split panel

Parameter	Default	Description
initialSplitRatio	0.5	Starting width ratio of the left panel [0, 1]
minSplitRatio	0.1	Minimum ratio after dragging
maxSplitRatio	0.9	Maximum ratio after dragging
dividerWidth	6.0	Width of the draggable vertical divider (dp)

DiffDetailScreen — code lines

Parameter	Default	Description
lineHeight	20.0	Fixed height per code line (dp)
linePadding	8.0	Horizontal padding inside each line cell (dp)
codeCanvasWidth	2000.0	Virtual canvas width for horizontal scroll (dp)

DiffDetailScreen — horizontal pan bar

Parameter	Default	Description
panBarHeight	24.0	Height of the bottom pan bar (dp)
panBarHandleWidth	48.0	Width of the pill handle (dp)
panBarHandleHeight	4.0	Height of the pill handle (dp)

DiffDetailScreen — highlights

Parameter	Default	Description
localHighlightColor	Color(0x334CAF50)	Semi-transparent green for left panel
incomingHighlightColor	Color(0x33FFC107)	Semi-transparent amber for right panel

DiffDetailScreen — scroll animation

Parameter	Default	Description
scrollAnimationDuration	Duration(milliseconds: 300)	Tap-to-scroll animation duration
scrollAnimationCurve	Curves.easeOut	Tap-to-scroll animation curve

RawViewPanel

Parameter	Default	Description
responsiveBreakpoint	600.0	Width (dp) at which side-by-side layout activates

Cards (MergeOverlay, DiffViewPanel)

Parameter	Default	Description
cardBorderRadius	12.0	Corner radius of choice cards
selectedBorderWidth	2.0	Border width of the selected card
unselectedBorderWidth	1.0	Border width of unselected cards
cardPadding	12.0	Inner padding of choice cards
cardAnimationDuration	Duration(milliseconds: 150)	Selection animation duration

Icons

Parameter	Default	Description
iconSize	20.0	Standard action icon size
smallIconSize	18.0	Small/secondary icon size

Text

Parameter	Default	Description
monoFontSize	13.0	Monospace content font size
smallLabelFontSize	11.0	Index / label font size
textFieldBorderRadius	8.0	Manual-edit TextField corner radius

Layout offsets

Parameter	Default	Description
fabBottomOffset	16.0	Raw view FAB bottom offset
fabRightOffset	16.0	Raw view FAB right offset
diffFabBottomOffset	72.0	Diff view FAB bottom offset (clears nav bar)
diffFabRightOffset	16.0	Diff view FAB right offset
listBottomPadding	80.0	List bottom padding (clears FAB)
overlayBodyBottomPadding	100.0	Overlay scroll body bottom padding (clears FAB)

---

File Type Details

JSON

• Accepts any valid JSON file whose root is a Map or List.
• Comparison walks the decoded JSON object graph directly with a lightweight\n built-in comparator (no external diff dependency).
• Web: file I/O (dart:io) is unavailable; raw view shows empty pages but diff\n view works when file paths are substituted with pre-loaded data.

SQLite

• Compares tables by name across both databases.
• Within each table, rows are matched by primary key when detectable (PRAGMA table_info); falls back to positional matching otherwise.
• Records are loaded lazily in pages of 100 rows during comparison.
• Requires the sqflite family of packages (included).
• Initialises the correct FFI factory per platform automatically.

---

Comparison Modes

ComparisonMode.allDiffs

Every field that has a different value between the two files appears in the diff list, including:

• Fields present in file 1 but missing in file 2 (valueB == null).
• Fields present in file 2 but missing in file 1 (valueA == null).
• Fields present in both but with different non-null values.

ComparisonMode.incompatibleOnly

Only true conflicts are shown — both sides must have a non-null value and those values must differ. This is useful when you want to ignore additive changes and focus only on genuine conflicts.

---

Merge Resolution

Each diff in diffView mode can be resolved in three ways inside the MergeOverlay:

Option	Result
Accept Local (File 1)	Uses diff.valueA
Accept Incoming (File 2)	Uses diff.valueB
Manual Edit	Uses the text typed into the editable field

Tapping "Confirm" stores the choice. The "Finalize" FAB is always visible and calls onMergeComplete with whatever has been resolved so far — you can finalise at any point.

Auto-accept compatible diffs

When showAcceptCompatibleButton: true, a toggle chip appears above the list. Enabling it automatically resolves all diffs where isCompatible == true (i.e. only one side has a value) by choosing the non-null side. Disabling the toggle removes only the auto-resolved entries, preserving any manual choices.

---

Architecture

comparable_version_sync/
├── lib/
│   ├── comparable_version_sync.dart     ← public barrel export
│   └── src/
│       ├── enums/
│       │   ├── comparison_mode.dart
│       │   ├── file_type.dart
│       │   └── return_type.dart
│       ├── models/
│       │   ├── diff_context.dart        ← per-field diff data
│       │   └── merge_result.dart        ← final merged output
│       ├── theme/
│       │   └── comparable_version_theme.dart  ← all visual knobs
│       ├── comparison/
│       │   ├── base_comparator.dart
│       │   ├── compatibility_checker.dart
│       │   ├── context_resolver.dart
│       │   ├── json_comparator.dart     ← built-in JSON comparator
│       │   └── sqlite_comparator.dart   ← uses sqflite
│       └── widgets/
│           ├── comparable_version_widget.dart  ← entry point
│           ├── diff_view_panel.dart
│           ├── merge_overlay.dart
│           ├── diff_detail_screen.dart
│           └── raw_view_panel.dart
└── lib/third_party/                     ← (no runtime code; only legacy vendor assets if present)

Public API surface (exported by the barrel):

• ComparableVersionWidget — the widget entry point
• ComparableVersionTheme — visual configuration
• FileType, ComparisonMode, ReturnType — enums
• DiffContext, MergeResult — data models

Everything else is internal.

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License

This package is APACHE 2.0 licensed. See LICENSE.