Access JSON properties dynamically like JavaScript using Swift 4.2's new @dynamicMemberLookup feature
Installation • Usage • License
DynamicJSON is a dynamically typed JSON parser built upon the new @dynamicMemberLookup
feature introduced by Chris Lattner in Swift 4.2. This allows us to access arbitrary object members which are resolved at runtime, allowing Swift to be as flexible as JavaScript when it comes to JSON.
if let jsonObject = try? JSONSerialization.jsonObject(with: data, options: []) as? [String: Any],
let user = jsonObject["user"] as? [String: Any],
let username = user["username"] as? String {
// ...
}
let username = JSON(data).user.username.string
pod 'DynamicJSON', '~> 2.0.2'
(if you run into problems, pod repo update
and try again)
github "saoudrizwan/DynamicJSON"
DynamicJSON.swift
into your project.And import DynamicJSON
in the files you'd like to use it.
Throw Any
thing into a JSON
object to get started
let json = JSON(Data())
JSON(123)
JSON(["key": "value"])
JSON(["element", 1])
JSON("Hello world")
JSON(false)
...or cast a literal as JSON
let json = "Hello world" as JSON
123 as JSON
[1, 2, 3] as JSON
let user: JSON = [
"username": "Saoud",
"age": 21,
"address": [
"zip": "12345",
"city": "San Diego"
]
]
Treat JSON
objects like you're in JavaScript Land
let dictionary = json.dictionary
let array = json[0].cars.array
let string = json.users[1].username.string
let nsnumber = json.creditCard.pin.number
let double = json[3][1].height.double
let int = json[0].age.int
let bool = json.biography.isHuman.bool
Note how JSON
doesn't actually have properties like cars
or users
, instead it uses dynamic member lookup to traverse through its associated JSON data to find the object you're looking for.
In case you have a key that's an actual property of JSON
, like number
or description
for example, just use the string subscript accessor like so:
let number = json.account.contact["number"].number
let description = json.user.biography["description"].string
JSON
conforms to Comparable
let json1 = JSON(jsonData1)
let json2 = JSON(jsonData2)
// Equality applies to all types (Dictionary, Array, String, NSNumber, Bool, NSNull)
let isEqual = json1 == json2
// Less/greater than only applies to NSNumbers (Double, Int) and Strings
let isLessThan = json1 < json2
let isLessThanOrEqual = json1 <= json2
let isGreaterThan = json1 > json2
let isGreaterThanOrEqual = json1 >= json2
Pretty print for debug purposes
print(json)
Convert to raw object
let anyObject = json.object
Convert to Data
let data = json.data() // optionally specify options...
DynamicJSON uses the MIT license. Please file an issue if you have any questions or if you'd like to share how you're using DynamicJSON.
DynamicJSON is in its infancy, but provides the barebones of a revolutionary new way to work with JSON in Swift. Please feel free to send pull requests of any features you think would add to DynamicJSON and its philosophy.
Contact me by email [email protected], or by twitter @sdrzn. Please create an issue if you come across a bug or would like a feature to be added.
@dynamicMemberLookup