json_theme

Description:

json theme

Table of Contents

json_theme
Live Example
Decoding
Schema Validation
Class Selection


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.
Important Note
Because this library allows for icons to be dynamically referenced, Flutter cannot tree shake icons because it has no way of knowing what icons may or may not be referenced. If you include this library, then you will need to add the --no-tree-shake-icons flag to your Flutter build or you will get an error stating that Flutter cannot tree shake the icons.
Live Example #

Web

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,
);
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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
}

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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

MaxLengthEnforcement
Plain string that must be one of:

enforced ==> MaxLengthEnforcement.enforced
none ==> MaxLengthEnforcement.none
truncateAfterCompositionEnds ==> MaxLengthEnforcement.truncateAfterCompositionEnds

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

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
decal ==> TileMode.decal
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