This is my attempt to implement some Sourcery templates which automatically generates JSON bindings for your struct
s and classes
.
My objective here is to provide a fully tested code generation template that will let you skip the pain of writing this code:
extension Contact: JSONDeserializable {
enum Fields: String {
case identifier = "id"
case firstName = "first_name"
case lastName = "last_name"
case age = "age"
}
init?(JSONObject: [String : Any]) {
guard let id = JSONObject[Fields.identifier.rawValue] as? String,
let firstName = JSONObject[Fields.firstName.rawValue] as? String,
let lastName = JSONObject[Fields.lastName.rawValue] as? String,
let age = JSONObject[Fields.age.rawValue] as? Int
else {
return nil
}
self.id = id
self.firstName = firstName
self.lastName = lastName
self.age = age
}
}
The JSON serialization/deserialization is based on two protocols.
protocol JSONDeserializable {
init?(JSONObject: [String: Any])
}
protocol JSONSerializable {
func toJSONObject() -> [String: Any]
}
With this tool, you do not need to implement these protocols, the Sourcery templates will do the boiler plate code for you.
To do this, all you need to do is conform to one (or both) of these protocols:
protocol AutoJSONDeserializable {}
protocol AutoJSONSerializable {}
And then run Sourcery using the templates found in the Templates/
folder of this repository.
Let say you have a model struct like this one:
struct Contact {
let id: String
let firstName: String
let lastName: String
let age: Int
}
Making it conform to AutoJSONDeserializable would result make it support this JSON:
{
"id": "SomeID",
"firstName": "John",
"lastName": "Doe'"
}
- Primitive JSON types (String, Int, Double).
- ISO8601 formatted dates.
- Optionals.
- Nested structures.
- Nested types with custom JSONSerializable or JSONDeserializable implementation.
- JSONKey annotation.
- Arrays of primitive JSON types,
Date
s and JSON*able types.
When mapping your JSON to your model structure, you may sometimes want to use a different attribute name as the one in the JSON file.
Let's say you have this JSON:
{
"id": "SomeID",
"first_name": "John",
"last_name": "Doe'"
}
As you can see, the naming convention does not follow camel case. To fix this you can use Sourcery annotations.
On a property, you can define the JSONKey
attribute with the JSON name you want to bind the property to:
struct Contact {
let id: String
// sourcery: JSONKey = "first_name"
let firstName: String
// sourcery: JSONKey = "last_name"
let lastName: String
}
If you want to nest some types that are not currently supported (for example: enums with associated values) or if you want to provide a special implementation of the serde methods for those types, you can simply implement the JSONSerializable
and/or JSONDeserializable
protocols.
For example, if Job
is an enum, you can still add it to Contact
:
struct Contact {
let id: String
let job: Job
}
enum Job: JSONSerializable {
[…]
func toJSONObject() -> [String: Any] {
// Implemnt your custom serializer.
}
}
Add pod 'Sourcery-AutoJSONSerializable'
to your Podfile.
Configure your .sourcery.yml
file with this:
[…]
templates:
- Pods/Sourcery-AutoJSONSerializable/Templates/
[…]
Add those protocols anywhere in your source code:
protocol AutoJSONSerializable {}
protocol AutoJSONDeserializable {}
public protocol JSONSerializable {
func toJSONObject() -> [String: Any]
}
protocol JSONDeserializable {
init?(JSONObject: [String: Any])
}
And, finally, to use it on a structure, just add one of the "Auto" protocols:
struct Contact: AutoJSONSerializable {
[...]
}
To install just copy the following source files in your project:
Sources/AutoJSONSerialization/AutoJSONSerializable.swift
Sources/AutoJSONSerialization/AutoJSONDeserializable.swift
And then copy the Templates files and configure Sourcery.