@radixdlt/data-formats
v2.1.1 Data
@radixdlt/data-formats
Usage
JSON Decoding
Examples
Without dependencies, using provided taggedStringDecoder:
import { JSONDecoding, taggedStringDecoder } from '@radixdlt/data-formats'
const strTagDecoder = taggedStringDecoder(':str:')((value) => ok(value))
const { fromJSON } = JSONDecoding.withDecoders(strTagDecoder).create()
fromJSON(':str:xyz') // Ok('xyz')
An object with dependencies:
import { JSONDecoding, taggedStringDecoder } from '@radixdlt/data-formats'
import { ok } from 'neverthrow'
const strTagDecoder = taggedStringDecoder(':str:')((value) => ok(value))
const Object1 = {
...JSONDecoding.withDecoders(strTagDecoder).create()
}
const tstTagDecoder = taggedStringDecoder(':tst:')((value) => ok(value))
const { fromJSON } = JSONDecoding
.withDependencies(Object1)
.withDecoders(testTagDecoder)
.create()
fromJSON({
a: ':str:foo',
b: ':tst:bar'
}) // ok({ a: 'foo', b: 'bar' })
JSON decoding takes an object and applies decoder
s to each key-value pair. taggedObjectDecoder
and taggedStringDecoder
are provided, but you can easily define a new decoder. Here is how taggedStringDecoder
is defined:
import { decoder } from '@radixdlt/data-formats'
export const taggedStringDecoder = (tag: string) => <T>(
algorithm: (value: string) => Result<T, Error>,
): Decoder =>
decoder<T>((value) =>
isString(value) && `:${value.split(':')[1]}:` === tag
? algorithm(value.slice(tag.length))
: undefined,
)
A decoder
should supply a function that defines how the decoding should be applied. First it should do some validation logic (does this decoder apply to this value?), in this case checking if the value is a string and if has a matching tag. Then, apply some algorithm
function, which is the actual decoding (create an instance of some object). If the validation fails, the decoder has to return undefined
.
npm i @radixdlt/[email protected]
Metadata
- Apache-2.0
- >=15.5.0 <16
- Alexander Cyon
- released 7/13/2021