A library to dynamically generate a ThemeData object from a JSON file or dynamic map object


License
MIT

Documentation

json_theme

Library to encode and decode ThemeData and associated objects to / from JSON. This is currently an early release of the library.

This provides two main classes.

  • ThemeDecoder -- Provides functionality to decode theme related objects from JSON maps.
  • ThemeEncoder -- Provides functionality to encode theme related objects into JSON maps.

Note: Encoding and decoding is mostly bi-directionally compatible, but it is not fully bi-directionally compatible. That's because there are some properties in theme objects that exist on the constructors, but are not re-exposed as properties and only exposed as dynamic calculated values. Likewise, there are some dynamic classes (specifically custom Shape, Slider, and Decoration classes) that have no meaningful way of being encoded to JSON nor decoded from JSON.

The decodes utilize a JSON Schema validator to ensure the JSON is well formed. This validation is enabled by default in debug mode and disabled in release mode for performance reasons. Even in development mode, you can disable the validation by setting the optional validate parameter to false.

Live Example

Decoding

The framework accepts both JSON-compatible objects as well as actual concrete instances being passed to the decode functions. For example, the following will properly decode:

var appBarTheme = ThemeDecoder.decodeAppBarTheme({
    'brightness': Brightness.dark,
    'color': '#ffdddddd'
  }, 
  validate: false,
);

Schema Validation

The framework comes with a built-in JSON Schema validator. This validator is set to be enabled by default in debug mode but disabled in release and profile mode.

The JSON Schema validator can only validate pure JSON based objects. It cannot validate mixed JSON and concrete objects. If your application uses mixed JSON and concrete objects in the implementation you will either need to disable validation in the decode calls where mixed objects can be used (as is done in the example above) or disable validation globally for the entire application via:

import 'package:json_theme/json_theme_schemas.dart';

void main() {
  SchemaValidator.enabled = false;

  /// rest of app initialization goes here
}

Class Selection

As close as possible, the names used in the Dart APIs are replicated. However, there are instances where the class is different for things like Shape objects, or there's an enum like VerticalDirection. Those are all documented in this section.

Alignment

Plain string that must be one of:

  • bottomCenter ==> Alignment.bottomCenter
  • bottomLeft ==> Alignment.bottomLeft
  • bottomRight ==> Alignment.bottomRight
  • center ==> Alignment.center
  • centerLeft ==> Alignment.centerLeft
  • centerRight ==> Alignment.centerRight
  • topCenter ==> Alignment.topCenter
  • topLeft ==> Alignment.topLeft
  • topRight ==> Alignment.topRight

AutovalidateMode

Plain string that must be one of:

  • always ==> AutovalidateMode.always
  • disabled ==> AutovalidateMode.disabled
  • onUserInteraction ==> AutovalidateMode.onUserInteraction

Axis

Plain string that must be one of:

  • horizontal ==> Axis.horizontal
  • vertical ==> Axis.vertical

BlendMode

Plain string that must be one of:

  • clear ==> BlendMode.clear
  • color ==> BlendMode.color
  • colorBurn ==> BlendMode.colorBurn
  • colorDodge ==> BlendMode.colorDodge
  • darken ==> BlendMode.darken
  • difference ==> BlendMode.difference
  • dst ==> BlendMode.dst
  • dstATop ==> BlendMode.dstATop
  • dstIn ==> BlendMode.dstIn
  • dstOut ==> BlendMode.dstOut
  • dstOver ==> BlendMode.dstOver
  • exclusion ==> BlendMode.exclusion
  • hardLight ==> BlendMode.hardLight
  • hue ==> BlendMode.hue
  • lighten ==> BlendMode.lighten
  • luminosity ==> BlendMode.luminosity
  • modulate ==> BlendMode.modulate
  • multiply ==> BlendMode.multiply
  • overlay ==> BlendMode.overlay
  • plus ==> BlendMode.plus
  • saturation ==> BlendMode.saturation
  • screen ==> BlendMode.screen
  • softLight ==> BlendMode.softLight
  • src ==> BlendMode.src
  • srcATop ==> BlendMode.srcATop
  • srcIn ==> BlendMode.srcIn
  • srcOut ==> BlendMode.srcOut
  • srcOver ==> BlendMode.srcOver
  • xor ==> BlendMode.xor

BorderRadius

Requires a type value that must be one of:

  • all ==> BorderRadius.all
  • circular ==> BorderRadius.circular
  • horizontal ==> BorderRadius.horizontal
  • only ==> BorderRadius.only
  • vertical ==> BorderRadius.vertical

BorderStyle

Plain string that must be one of:

  • none ==> BorderStyle.none
  • solid ==> BorderStyle.solid

BottomNavigationBarType

Plain string that must be one of:

  • fixed ==> BottomNavigationBarType.fixed
  • shifting ==> BottomNavigationBarType.shifting

BoxFit

Plain string that must be one of:

  • contain ==> BoxFit.contain
  • cover ==> BoxFit.cover
  • fill ==> BoxFit.fill
  • fitHeight ==> BoxFit.fitHeight
  • fitWidth ==> BoxFit.fitWidth
  • none ==> BoxFit.none
  • scaleDown ==> BoxFit.scaleDown

ButtonBarLayoutBehavior

Plain string that must be one of:

  • constrained ==> ButtonBarLayoutBehavior.constrained
  • padded ==> ButtonBarLayoutBehavior.padded

ButtonTextTheme

Plain string that must be one of:

  • accent ==> ButtonTextTheme.accent
  • normal ==> ButtonTextTheme.normal
  • primary ==> ButtonTextTheme.primary

Clip

Plain string that must be one of:

  • antiAlias ==> Clip.antiAlias
  • antiAliasWithSaveLayer ==> Clip.antiAliasWithSaveLayer
  • hardEdge ==> Clip.hardEdge
  • none ==> Clip.none

CrossAxisAlignment

Plain string that must be one of:

  • baseline ==> CrossAxisAlignment.baseline
  • center ==> CrossAxisAlignment.center
  • end ==> CrossAxisAlignment.end
  • start ==> CrossAxisAlignment.start
  • stretch ==> CrossAxisAlignment.stretch

CrossFadeState

Plain string that must be one of:

  • showFirst ==> CrossFadeState.showFirst
  • showSecond ==> CrossFadeState.showSecond

DecorationPosition

Plain string that must be one of:

  • background ==> DecorationPosition.background
  • foreground ==> DecorationPosition.foreground

DragStartBehavior

Plain string that must be one of:

  • down ==> DragStartBehavior.down
  • start ==> DragStartBehavior.start

FilterQuality Plain string that must be one of:

  • high ==> FilterQuality.high
  • low ==> FilterQuality.low
  • medium ==> FilterQuality.medium
  • none ==> FilterQuality.none

FlexFit

Plain string that must be one of:

  • loose ==> FlexFit.loose
  • tight ==> FlexFit.tight

FloatingActionButtonAnimator

Plain string that must be one of:

  • scaling ==> FloatingActionButtonAnimator.scaling

FloatingActionButtonLocation

Plain string that must be one of:

  • centerDocked ==> FloatingActionButtonLocation.centerDocked
  • centerFloat ==> FloatingActionButtonLocation.centerFloat
  • centerTop ==> FloatingActionButtonLocation.centerTop
  • endDocked ==> FloatingActionButtonLocation.endDocked
  • endFloat ==> FloatingActionButtonLocation.endFloat
  • endTop ==> FloatingActionButtonLocation.endTop
  • miniCenterDocked ==> FloatingActionButtonLocation.miniCenterDocked
  • miniCenterFloat ==> FloatingActionButtonLocation.miniCenterFloat
  • miniCenterTop ==> FloatingActionButtonLocation.miniCenterTop
  • miniEndDocked ==> FloatingActionButtonLocation.miniEndDocked
  • miniEndFloat ==> FloatingActionButtonLocation.miniEndFloat
  • miniEndTop ==> FloatingActionButtonLocation.miniEndTop
  • miniStartDocked ==> FloatingActionButtonLocation.miniStartDocked
  • miniStartFloat ==> FloatingActionButtonLocation.miniStartFloat
  • miniStartTop ==> FloatingActionButtonLocation.miniStartTop
  • startDocked ==> FloatingActionButtonLocation.startDocked
  • startFloat ==> FloatingActionButtonLocation.startFloat
  • startTop ==> FloatingActionButtonLocation.startTop

FloatingLabelBehavior

Plain string that must be one of:

  • always ==> FloatingLabelBehavior.always
  • auto ==> FloatingLabelBehavior.auto
  • never ==> FloatingLabelBehavior.never

FontWeight

Plain string that must be one of:

  • bold ==> FontWeight.bold
  • normal ==> FontWeight.normal
  • w100 ==> FontWeight.w100
  • w200 ==> FontWeight.w200
  • w300 ==> FontWeight.w300
  • w400 ==> FontWeight.w400
  • w500 ==> FontWeight.w500
  • w600 ==> FontWeight.w600
  • w700 ==> FontWeight.w700
  • w800 ==> FontWeight.w800
  • w900 ==> FontWeight.w900

FontStyle

Plain string that must be one of:

  • italic ==> FontStyle.italic
  • normal ==> FontStyle.normal

Gradient

Requires a type value that must be one of:

  • linear ==> LinearGradient
  • radial ==> RadialGradient
  • sweep ==> SweepGradient

HitTestBehavior

Plain string that must be one of:

  • deferToChild ==> HitTestBehavior.deferToChild
  • opaque ==> HitTestBehavior.opaque
  • translucent ==> HitTestBehavior.translucent

ImageProvider

Requires a type value that must be one of:

  • asset ==> AssetImage
  • memory ==> MemoryImage
  • network ==> NetworkImage

ImageRepeat

Plain string that must be one of:

  • noRepeat ==> ImageRepeat.noRepeat
  • repeat ==> ImageRepeat.repeat
  • repeatX ==> ImageRepeat.repeatX
  • repeatY ==> ImageRepeat.repeatY

InputBorder

Requires a type value that must be one of:

  • outline ==> OutlineInputBorder
  • underline ==> UnderlineInputBorder

InteractiveInkFeatureFactory

Plain string that must be one of:

  • splash ==> InkSplash.splashFactory
  • ripple ==> InkRipple.splashFactory

MainAxisAlignment

Plain string that must be one of:

  • center ==> MainAxisAlignment.center
  • end ==> MainAxisAlignment.end
  • spaceAround ==> MainAxisAlignment.spaceAround
  • spaceBetween ==> MainAxisAlignment.spaceBetween
  • spaceEvenly ==> MainAxisAlignment.spaceEvenly
  • start ==> MainAxisAlignment.start

MainAxisSize

Plain string that must be one of:

  • min ==> MainAxisSize.min
  • max ==> MainAxisSize.max

MaterialTapTargetSize

Plain string that must be one of:

  • padded ==> MaterialTapTargetSize.padded
  • shrinkWrap ==> MaterialTapTargetSize.shrinkWrap

MaterialType

Plain string that must be one of:

  • button ==> MaterialType.button
  • canvas ==> MaterialType.canvas
  • card ==> MaterialType.card
  • circle ==>MaterialType.circle
  • transparency ==> MaterialType.transparency

MouseCursor

Requires a type value that must be one of:

  • defer ==> MouseCursor.defer
  • material ==> MouseCursor.material
  • system ==> MouseCursor.system
  • uncontrolled ==> MouseCursor.uncontrolled

NavigationRailLabelType

Plain string that must be one of:

  • all ==> NavigationRailLabelType.all
  • none ==> NavigationRailLabelType.none
  • selected ==> NavigationRailLabelType.selected

NotchedShape

Plain string that must be one of:

  • circular ==> CircularNotchedRectangle

OutlinedBorder Requires a type value that must be one of:

  • stadium ==> BeveledRectangleBorder
  • circle ==> CircleBorder
  • rectangle ==> ContinuousRectangleBorder
  • rounded ==> RoundedRectangleBorder
  • stadium ==> StadiumBorder

Overflow

Plain string that must be one of:

  • clip ==> Overflow.clip
  • visible ==> Overflow.visible

PageTransitionsBuilder

Plain string that must be one of:

  • clip ==> Overflow.clip
  • visible ==> Overflow.visible

Radius

Requires a type value that must be one of:

  • circular ==> Radius.circular
  • elliptical ==> Radius.elliptical
  • zero ==> Radius.zero

RangeSliderThumbShape

Requires a type value that must be one of:

  • round ==> RoundRangeSliderThumbShape

RangeSliderTickMarkShape

Plain string that must be one of: Requires a type value that must be one of:

  • round ==> RoundRangeSliderTickMarkShape

RangeSliderTrackShape

Plain string that must be one of:

  • rectangular ==> RectangularRangeSliderTrackShape
  • rounded ==> RoundedRectRangeSliderTrackShape

RangeSliderValueIndicatorShape

Requires a type value that must be one of:

  • paddle ==> PaddleRangeSliderValueIndicatorShape
  • rectangular ==> RectangularRangeSliderValueIndicatorShape

Rect

Requires a type value that must be one of:

  • center ==> Rect.fromCenter
  • circle ==> Rect.fromCircle
  • largest ==> Rect.largest
  • ltrb ==> Rect.fromLTRB
  • ltwh ==> Rect.fromLTWH
  • points ==> Rect.fromPoints
  • zero ==> Rect.zero

ScrollPhysics

Requires a type value that must be one of:

  • always ==> AlwaysScrollableScrollPhysics
  • bouncing ==> BouncingScrollPhysics
  • clamping ==> ClampingScrollPhysics
  • fixedExtent ==> FixedExtentScrollPhysics
  • never ==> NeverScrollableScrollPhysics
  • page ==> PageScrollPhysics
  • rangeMaintaining ==> RangeMaintainingScrollPhysics

ScrollViewKeyboardDismissBehavior

Plain string that must be one of:

  • manual ==> ScrollViewKeyboardDismissBehavior.manual
  • onDrag ==> ScrollViewKeyboardDismissBehavior.onDrag

ShapeBorder

Requires a type value that must be one of:

  • circle ==> CircleBorder
  • rectangle ==> ContinuousRectangleBorder
  • rounded ==> RoundedRectangleBorder

ShowValueIndicator

Plain string that must be one of:

  • always ==> ShowValueIndicator.always
  • never ==> ShowValueIndicator.never
  • onlyForContinuous ==> ShowValueIndicator.onlyForContinuous
  • onlyForDiscrete ==> ShowValueIndicator.onlyForDiscrete

SliderComponentShape

Plain string that must be one of:

  • noOverlay ==> SliderComponentShape.noOverlay
  • noOverlay ==> SliderComponentShape.noOverlay

SliderTickMarkShape

Plain string that must be one of:

  • noTickMark ==> SliderTickMarkShape.noTickMark

SliderTrackShape

Plain string that must be one of:

  • rectangular ==> RectangularSliderTrackShape
  • rounded ==> RoundedRectSliderTrackShape

SmartDashesType

Plain string that must be one of:

  • disabled ==> SmartDashesType.disabled
  • enabled ==> SmartDashesType.enabled

SmartQuotesType

Plain string that must be one of:

  • disabled ==> SmartQuotesType.disabled
  • enabled ==> SmartQuotesType.enabled

SnackBarBehavior

Plain string that must be one of:

  • fixed ==> SnackBarBehavior.fixed
  • floating ==> SnackBarBehavior.floating

StackFit

Plain string that must be one of:

  • expand ==> StackFit.expand
  • loose ==> StackFit.loose
  • passthrough ==> StackFit.passthrough

TabBarIndicatorSize

Plain string that must be one of:

  • label ==> ButtonTextTheme.label
  • tab ==> ButtonTextTheme.tab

TargetPlatform

Plain string that must be one of:

  • android ==> TargetPlatform.android
  • fuchsia ==> TargetPlatform.fuchsia
  • iOS ==> TargetPlatform.iOS
  • linux ==> TargetPlatform.linux
  • macOS ==> TargetPlatform.macOS
  • windows ==> TargetPlatform.windows

TextAlign

Plain string that must be one of:

  • center ==> TextAlign.center
  • end ==> TextAlign.end
  • justify ==> TextAlign.justify
  • left ==> TextAlign.left
  • right ==> TextAlign.right
  • start ==> TextAlign.start

TextAlignVertical

Plain string that must be one of:

  • bottom ==> TextAlignVertical.bottom
  • center ==> TextAlignVertical.center
  • top ==> TextAlignVertical.top

TextBaseline

Plain string that must be one of:

  • alphabetic ==> TextBaseline.alphabetic
  • ideographic ==> TextBaseline.ideographic

TextCapitalization

Plain string that must be one of:

  • characters ==> TextCapitalization.characters
  • none ==> TextCapitalization.none
  • sentences ==> TextCapitalization.sentences
  • words ==> TextCapitalization.words

TextDecoration

Plain string that must be one of:

  • lineThrough ==> TextDecoration.lineThrough
  • none ==> TextDecoration.none
  • overline ==> TextDecoration.overline
  • underline ==> TextDecoration.underline

TextDecorationStyle

Plain string that must be one of:

  • dashed ==> TextDecorationStyle.dashed
  • dotted ==> TextDecorationStyle.dotted
  • double ==> TextDecorationStyle.double
  • solid ==> TextDecorationStyle.solid
  • wavy ==> TextDecorationStyle.wavy

TextDirection

Plain string that must be one of:

  • ltr ==> TextDirection.ltr
  • rtl ==> TextDirection.rtl

TextInputAction

Plain string that must be one of:

  • continueAction ==> TextInputAction.continueAction
  • done ==> TextInputAction.done
  • emergencyCall ==> TextInputAction.emergencyCall
  • go ==> TextInputAction.go
  • join ==> TextInputAction.join
  • newline ==> TextInputAction.newline
  • next ==> TextInputAction.next
  • none ==> TextInputAction.none
  • previous ==> TextInputAction.previous
  • route ==> TextInputAction.route
  • search ==> TextInputAction.search
  • send ==> TextInputAction.send
  • unspecified ==> TextInputAction.unspecified

TextInputType

Plain string that must be one of:

  • datetime ==> TextInputType.datetime
  • emailAddress ==> TextInputType.emailAddress
  • multiline ==> TextInputType.multiline
  • name ==> TextInputType.name
  • number ==> TextInputType.number
  • phone ==> TextInputType.phone
  • streetAddress ==> TextInputType.streetAddress
  • text ==> TextInputType.text
  • url ==> TextInputType.url
  • visiblePassword ==> TextInputType.visiblePassword

TextOverflow

Plain string that must be one of:

  • clip ==> TextOverflow.clip
  • ellipsis ==> TextOverflow.ellipsis
  • fade ==> TextOverflow.fade
  • visible ==> TextOverflow.visible

TextWidthBasis

Plain string that must be one of:

  • longestLine ==> TextWidthBasis.longestLine
  • parent ==> TextWidthBasis.parent

TileMode

Plain string that must be one of:

  • clamp ==> TileMode.clamp
  • mirror ==> TileMode.mirror
  • repeated ==> TileMode.repeated

VerticalDirection

Plain string that must be one of:

  • down ==> VerticalDirection.down
  • up ==> VerticalDirection.up

VisualDensity

Plain string that must be one of:

  • adaptivePlatformDensity ==> VisualDensity.adaptivePlatformDensity
  • comfortable ==> VisualDensity.comfortable
  • compact ==> VisualDensity.compact
  • standard ==> VisualDensity.standard