Work with JSON using a schema!
JSON-Typedef is an easy-to-learn, portable, and standardized way to describe the shape of your JSON data. This library provides encoders and decoders for the JSON-Typedef schema format, and can generate Gleam encoders and decoders for a given schema.
For example, if you have this JSON-Typedef schema:
{
"properties": {
"id": { "type": "string" },
"createdAt": { "type": "timestamp" },
"karma": { "type": "int32" },
"isAdmin": { "type": "boolean" }
}
}Then you can use this package to generate this Gleam source code:
import decode
import gleam/json
pub type Data {
Data(
created_at: String,
id: String,
is_admin: Bool,
karma: Int,
)
}
pub fn data_decoder() -> decode.Decoder(Data) {
decode.into({
use created_at <- decode.parameter
use id <- decode.parameter
use is_admin <- decode.parameter
use karma <- decode.parameter
Data(created_at:, id:, is_admin:, karma:)
})
|> decode.field("createdAt", decode.string)
|> decode.field("id", decode.string)
|> decode.field("isAdmin", decode.bool)
|> decode.field("karma", decode.int)
}
pub fn data_to_json(data: Data) -> json.Json {
json.object([
#("createdAt", json.string(data.created_at)),
#("id", json.string(data.id)),
#("isAdmin", json.bool(data.is_admin)),
#("karma", json.int(data.karma)),
])
}Further documentation can be found at https://hexdocs.pm/json_typedef.