formstack 2.5.0

A cross-platform ResearchKit and ODK alternative for Flutter. Build dynamic forms and surveys with 35 input types, 35+ validators, repeat groups, offline save, and multi-language.

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

2.5.0 - 2026-04-02

Added

• 2 new example demo screens: "Data Collection (ODK)" and "Multi-Language & Offline" (total: 12 demos)
• Data Collection demo covers: RepeatStep, calculate fields, hidden fields, cascading selects, barcode, audio, geotrace, geoshape
• Multi-Language demo covers: FormStackLocale with EN/ES/FR, DisplayStep with listTile data, runtime language switching
• geotrace and geoshape added to README input type tables
• Form-level defaultStyle parameter for applying UIStyle to all steps at once
• JSON theme key at form level for form-wide styling from JSON

Changed

• Example app now demonstrates all 35 input types and all 9 step types
• README examples table expanded to 12 demo screens
• Architecture file listing updated with all new files
• Input type count corrected to 36 throughout all docs

2.4.0 - 2026-04-02

Added

• FormStackTheme - centralized theme system with responsive sizing, dark/light mode colors, and accessibility helpers
• Responsive layout: all widgets adapt to mobile (< 600px), tablet (600-1200px), and desktop (> 1200px) screens
• Dark mode support: all colors resolve from Theme.of(context).colorScheme instead of hardcoded values
• Semantics wrappers for accessibility on interactive elements
• FormStackTheme.responsiveMaxWidth(), responsiveInputWidth(), responsivePadding(), responsiveIconSize(), responsiveButtonHeight()
• Theme-aware NPS colors (npsDetractorColor, npsPassiveColor, npsPromoterColor)
• Canvas colors adapt to dark mode (canvasStrokeColor, canvasBackgroundColor)

Changed

• Replaced 47 hardcoded color values with theme-aware alternatives across all view files
• Replaced 45+ hardcoded BoxConstraints with responsive sizing
• Error text uses Theme.of(context).colorScheme.error instead of Colors.red
• Input backgrounds use colorScheme.surfaceContainerHighest instead of hardcoded grey
• Borders use colorScheme.outline instead of Colors.grey
• Buttons use responsive heights based on screen size
• UIStyle expanded with 7 new properties: inputBackground, inputTextColor, titleColor, subtitleColor, iconColor, cardBackground, fontSize - all settable from JSON
• Form-level defaultStyle parameter applies to all steps without individual styling
• JSON theme key at form level applies default styling to all steps in that form

2.3.0 - 2026-04-02

Added

• 2 new input types: geotrace (trace path on map), geoshape (draw polygon on map)
• Offline save & resume via FormPersistence interface (enablePersistence, saveDraft, resumeDraft, deleteDraft, listDrafts)
• InMemoryFormPersistence built-in implementation for testing
• FormDraft serializable model for draft state
• ExternalDataProvider interface for loading options from CSV/API/database
• StaticDataProvider built-in implementation with fromCsv factory
• QuestionStep.optionsProvider and optionsSourceId for external data-backed choices
• All new types supported in JSON parser

2.2.0 - 2026-04-02

Added

• 4 new input types: hidden (data-only, no UI), calculate (auto-computed from other results), barcode (QR/barcode scanner), audio (recording with timer)
• RepeatStep - dynamic repeating sections where users add/remove entries (modeled after ODK repeat)
• Cascading selects via QuestionStep.choiceFilter callback - filter options based on other step results (Country -> State -> City)
• FormStackLocale class for multi-language support with runtime language switching, t() and tf() translation methods, and JSON loading
• QuestionStep.calculateCallback for auto-computing values from collected results
• QuestionStep.calculateExpression for declarative calculate formulas
• Step view widget caching to preserve state during navigation
• All new types fully supported in JSON schema parser

Fixed

2.1.1 - 2026-04-02

Fixed

• Step view widget caching to prevent state loss during navigation (TextEditingController text, slider values, selected choices now preserved when navigating back)
• Controller and FocusNode memory leaks caused by widget recreation on every step change
• Cache cleared on form reset via clearResult() for clean restarts
• Step timestamps (startTime, endTime) reset properly on form clear

2.1.0 - 2026-04-02

Added

• boolean input type - Yes/No toggle buttons
• imageChoice input type - select from a grid of images with labels
• ReviewStep - displays all collected answers for review before submission
• ConsentStep with ConsentSection model and 8 predefined section types (overview, dataGathering, privacy, dataUse, timeCommitment, studyTasks, withdrawing, custom)
• Built-in progress bar UI with step counter ("Step 3 of 10") and percentage
• Result timestamps (startTime, endTime) recorded per step for analytics
• Static image support via titleIconImagePath (asset or network URL)
• Video URL support in InstructionStep via videoUrl
• dateRange validator with minDate/maxDate bounds
• ResultFormat public constructor for custom validator subclassing
• BaseStepView and FormStepView exported for custom input widget creation
• StepResult and TaskResult classes for structured result hierarchy (modeled after ResearchKit's ORKTaskResult)
• Step lifecycle callbacks: onStepWillPresent, onStepDidComplete
• API methods: getStep(), getStepResult(), getTaskResult(), exportAsJson()
• ResearchKit migration guide in README with side-by-side Swift/Dart examples
• New exports: ReviewStep, ConsentStep, ConsentSection, ConsentSectionType, BaseStepView, FormStepView, StepResult, TaskResult

2.0.0 - 2026-04-02

Added

• 8 new input types: slider, rating, nps, consent, signature, ranking, phone, currency
• 12 new validators: min, max, range, minLength, maxLength, pattern, minSelections, maxSelections, fileSize, iban, consent, compose
• FormStep properties: helperText, defaultValue, semanticLabel
• QuestionStep properties: minValue, maxValue, stepValue, minSelections, maxSelections, consentText, currencySymbol, phoneCountryCode, ratingCount
• New exports: RelevantCondition, ExpressionRelevant, DynamicConditionalRelevant, NestedStep, DisplayStep, UIStyle
• Full JSON schema support for all new input types and properties
• Comprehensive example app with 10 demo screens
• Dartdoc comments on all public API classes and members

Changed

• Renamed formKitForm to formStackForm across codebase
• Renamed TextFeildWidgetView to TextFieldWidgetView
• Renamed inputBoder() to inputBorder() across all input fields
• Renamed intput to input in expression evaluators
• Renamed htm_field.dart to html_input_field.dart
• Renamed mapview_field.dart to map_input_field.dart
• Replaced GlobalKey anti-pattern with ValueNotifier in BaseStepView and CompletionStepView
• Updated index.html to modern FlutterLoader.load initialization
• Updated README with complete documentation, screenshots, and JSON schema reference

Fixed

• Memory leak: OTP field controllers recreated on every build
• Memory leak: verification code list growing indefinitely on rebuilds
• Memory leak: addPostFrameCallback firing on every rebuild in text, nested, and completion views
• Performance: image memory bloat from full-resolution decoding (added cacheWidth/cacheHeight)
• Performance: dynamic key-value controller text resetting on every build
• Fixed typos in class names (_TextesultType, _MultipleChoiceesultType)
• Fixed nextFormSatck typo in formstack_form.dart
• Cleaned up dead commented-out code in htm_field.dart and web_view.dart
• Removed unnecessary imports across all internal files
• Added cacheExtent to all ListView widgets for smoother scrolling

Updated

• google_maps_flutter: ^2.14.0 -> ^2.17.0
• google_maps_flutter_web: ^0.5.14+3 -> ^0.6.2
• dio: ^5.9.0 -> ^5.9.2
• uuid: ^4.5.2 -> ^4.5.3
• file_picker: ^10.3.7 -> ^10.3.10
• webview_flutter: ^4.13.0 -> ^4.13.1
• google_maps: ^8.1.1 -> ^8.2.0
• flutter_lints: ^2.0.0 -> ^6.0.0 (example)

1.1.2 - 2024-12-01

Changed

• Removed performance analysis file
• Updated version to 1.1.2

1.1.1 - 2024-11-15

Fixed

• Memory leak in Google Places autocomplete stream subscription
• Component disposal in nested step views
• Undefined mounted property in completion step view
• Auto-trigger callback firing multiple times

Changed

• Added cache size limit (50 items) to prevent unbounded memory growth
• Optimized image memory usage by clearing file results after encoding
• Optimized controller recreation to only occur when form step result changes
• Reduced unnecessary setState calls in base step view
• Added proper GoogleMapController disposal
• Added lazy loading for background animations

Updated

• webview_flutter: ^4.9.0 -> ^4.13.0
• dio: ^5.8.0+1 -> ^5.9.0
• uuid: ^4.5.1 -> ^4.5.2
• lottie: ^3.3.1 -> ^3.3.2
• file_picker: ^8.3.7 -> ^10.3.7
• google_maps_flutter_web: ^0.5.12+2 -> ^0.5.14+3
• google_maps_flutter: ^2.12.3 -> ^2.14.0
• http: ^1.4.0 -> ^1.6.0

1.1.0 - 2024-10-01

Changed

• Initial release with dependency updates and optimizations

0.9.33 - 2024-06-01

Added

• Nested step with OR condition validation expression

0.9.4 - 2024-03-01

Added

• Nested step OR condition for multiple components

0.7.7 - 2023-12-01

Added

• Location picker with Google Maps

0.7.5 - 2023-11-01

Added

• HTML editor input type

0.7.4 - 2023-10-15

Added

• Dropdown button with component styles (minimal and basic)
• Dynamic key-value widget

0.7.0 - 2023-10-01

Changed

• Date format result uses UTC format

0.6.4 - 2023-09-15

Added

• Choice field with toggle switch selection type

0.6.3 - 2023-09-01

Added

• OTP view support
• File input type (single file selection)

0.6.1 - 2023-08-15

Added

• Disable UI fields dynamically via setDisabledUI

0.6.0 - 2023-08-01

Added

• Set error messages dynamically via setError
• Set form data dynamically via setResult

0.5.1 - 2023-07-15

Changed

• Renamed NestedQuestionStep to NestedStep

0.4.0 - 2023-07-01

Added

• NestedStep to display multiple questions on a single screen

0.2.10 - 2023-06-01

Changed

• Documentation updates and code optimisation

0.1.3 - 2023-05-15

Added

• Example application

0.1.1 - 2023-05-01

Added

• Initial release with model-based UI rendering