polkadart_scale_codec

Description:

polkadart scale codec

polkadart_scale_codec #
polkadart_scale_codec is a flutter and dart library for encoding and decoding types supported by polkadot.
Lets Get Started #
Supported types: #



Types
Sign




Unsigned Int
u8, u16, u32, u64, u128, u256


Signed Int
i8, i16, i32, i64, i128, i256


String
Str


Boolean
bool


Compact
Compact<T>


Enum
_enum


Composite
{}


FixedVec
[u8, length]


BitVec
BitVec


Option
Option<T>


Tuple
(K, V, T....)


Result
Result<Ok, Err>



Usage #
Unsigned Integers ( u8 | u16 | u32 ) #
//
// Encode
var output = HexOutput();

final value = 69;

U8Codec.codec.encodeTo(value, output);

// 0x45
var encodedHex = output.toString();

//
// Decode
var input = Input.fromHex(encodedHex);

// 69
var decoded = U8Codec.codec.decode(input);
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Unsigned Integers ( u64 | u128 | u256 ) #
//
// Encode
var output = HexOutput();

final value = BigInt.parse('115792089237316195423570985008687907853269984665640564039457584007913129639935');

U256Codec.codec.encodeTo(value, output);

// 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
var encodedHex = output.toString();

//
// Decode
var input = Input.fromHex(encodedHex);

// BigInt.parse('115792089237316195423570985008687907853269984665640564039457584007913129639935');
var decoded = U256Codec.codec.decode(input);
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Signed Integers ( i8 | i16 | i32 ) #
//
// Encode
var output = HexOutput();

final value = -128;

I8Codec.codec.encodeTo(value, output);

// 0x80
var encodedHex = output.toString();

//
// Decode
var input = Input.fromHex(encodedHex);

// -128
var decoded = I8Codec.codec.decode(input);
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Signed Integers ( i64 | i128 | i256 ) #
//
// Encode
var output = HexOutput();

final value = BigInt.parse('-9223372036854775808');

I64Codec.codec.encodeTo(value, output);

// 0x0000000000000080
var encodedHex = output.toString();

//
// Decode
var input = Input.fromHex(encodedHex);

// BigInt.parse('-9223372036854775808')
var decoded = I64Codec.codec.decode(input);
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Compact #
//
// Encode
var output = HexOutput();

final value = 69;

CompactCodec.codec.encodeTo(value, output);

// 0x1501
var encodedHex = output.toString();

//
// Decode
var input = Input.fromHex(encodedHex);

// 69
var decoded = CompactCodec.codec.decode(input);
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Option #
final value = Option.some(true);

final output = HexOutput();

OptionCodec(BoolCodec.codec).encodeTo(value, output);

// 0x0101
var encodedHex = output.toString();

final input = Input.fromHex(encodedHex);

// Option.some(true)
var decoded = OptionCodec(BoolCodec.codec).decode(input);

// or
// None
final value = Option.none();


final output = HexOutput();

OptionCodec(BoolCodec.codec).encodeTo(value, output);

// 0x00
var encodedHex = output.toString();

final input = Input.fromHex(encodedHex);

// Option.none()
var decoded = OptionCodec(BoolCodec.codec).decode(input);
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BitVec #
// Initializing Codec object
final codec = BitSequenceCodec(BitStore.U8, BitOrder.LSB);

final value = '11111';

final bitArray = BitArray.parseBinary(value);

final output = HexOutput();

codec.encodeTo(value, output);

// 0x1f
final encodedHex = output.toString();

final input = Input.fromHex(encodedHex);

// BitArray.parseBinary('11111')
var decoded = codec.decode(input);
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Enum #
// ignore: unnecessary_cast
final extraDataCodec = CompositeCodec({
'index': U8Codec.codec,
'name': StrCodec.codec,
'customTuple': TupleCodec([
SimpleEnumCodec.fromList(['Red', 'Orange']),
BoolCodec.codec,
]),
}) as Codec;

final codec = ComplexEnumCodec.sparse(
{
0: MapEntry('Plain', StrCodec.codec),
1: MapEntry('ExtraData', extraDataCodec),
},
);

final value = MapEntry('ExtraData', );
final output = HexOutput();

codec.encodeTo(value, output);

// 0x010124706f6c6b61646172740001
final encodedHex = output.toString();

final input = Input.fromHex(encodedHex);

// MapEntry('ExtraData', {
// 'index': 1,
// 'name': 'polkadart',
// 'customTuple': ['Red', true],
// })
var decoded = codec.decode(input);
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Composite #
// Composite Codec
final codec = CompositeCodec({
'index': U8Codec.codec,
'name': StrCodec.codec,
'customTuple': TupleCodec([
SimpleEnumCodec.fromList(['Red', 'Orange']),
BoolCodec.codec,
]),
}) as Codec;

final value = {
'index': 1,
'name': 'polkadart',
'customTuple': ['Red', true],
};

final output = HexOutput();

codec.encodeTo(value, output);

// 0x0124706f6c6b61646172740001
final encodedHex = output.toString();

final input = Input.fromHex(encodedHex);

// {
// 'index': 1,
// 'name': 'polkadart',
// 'customTuple': ['Red', true],
// }
var decoded = codec.decode(input);
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Result<Ok, Err> #
// Creates the registry for parsing the types
final registry = Registry();

// register the customCodec of your choice
registry.registerCustomCodec(<String, dynamic>{'A':'Result<u8, bool>'});

// Initialize the scale codec
final codec = ScaleCodec(registry);

final output = HexOutput();

codec.encodeTo('A', MapEntry('Ok', 42), output);

// 0x002a
final encodedHex = output.toString();

final input = Input.fromHex(encodedHex);

// MapEntry('Ok', 42)
var decoded = codec.decode('A', input);


// or
//
// For Err field
//
final value = MapEntry('Err', false);

codec.encodeTo('A', value, output);
// 0x0100
final encodedHex = output.toString();

// MapEntry('Err', false)
var decoded = codec.decode('A', input);
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Resources #

substrate.dev
Parity-scale-codec
Polkadot.js
Squid

License

For personal and professional use. You cannot resell or redistribute these repositories in their original state.

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