⚠ Important Notice: Farewell ws... hello Networking !
Networking is the next generation of the ws project. Think of it as ws 2.0 built for iOS13. It uses Combine native Apple's framework over Then Promise Library, removes Arrow dependency to favour Codable (Arrow can still be adapted easily though) and removes the Alamofire dependency in favour of a simpler purely native URLSession implementation. In essence, less dependencies and more native stuff with an almost identical api. If your app supports iOS13 and up, it is strongly advised to migrate to Networking. WS will be "maintained" for backwards compatibility reasons but consider it deprected starting iOS13.
ws
Reason - Example - Installation
let ws = WS("http://jsonplaceholder.typicode.com")
ws.get("/users").then { json in
// Get back some json \o/
}
Because JSON apis are used in 99% of iOS Apps, this should be simple.
We developers should focus on our app logic rather than boilerplate code .
Less code is better code
Try it!
ws is part of freshOS iOS toolset. Try it in an example App ! Download Starter Project
How
By providing a lightweight client that automates boilerplate code everyone has to write.
By exposing a delightfully simple api to get the job done simply, clearly, quickly.
Getting swift models from a JSON api is now a problem of the past
What
- Build concise Apis
- Automatically maps your models
- Built-in network logger
- Stands on the shoulder of giants (Alamofire & Promises)
- Pure Swift, Simple & Lightweight
Usage
Bare JSON
import ws // Import ws at the top of your file
import Arrow // Import Arrow to get access to the JSON type
class ViewController: UIViewController {
// Set webservice base URL
let ws = WS("http://jsonplaceholder.typicode.com")
override func viewDidLoad() {
super.viewDidLoad()
// Get back some json instantly \o/
ws.get("/users").then { (json:JSON) in
print(json)
}
}
}
Set up Model parsing
Create a User+JSON.swift
file and map the JSON keys to your model properties
import Arrow
extension User: ArrowParsable {
mutating func deserialize(_ json: JSON) {
identifier <-- json["id"]
username <-- json["username"]
email <-- json["email"]
}
}
Note: ws
uses Arrow
for JSON Parsing
https://github.com/freshOS/Arrow
Choose what you want back
Here you are going to create a function that wraps your request. There are different ways of writing that function depending on what you want back. An empty block, the JSON, the model or the array of models.
func voidCall() -> Promise<Void> {
return ws.get("/users")
}
func jsonCall() -> Promise<JSON> {
return ws.get("/users")
}
func singleModelCall() -> Promise<User> {
return ws.get("/users/3")
}
func modelArrayCall() -> Promise<[User]> {
return ws.get("/users")
}
As you can notice, only by changing the return type,
ws automatically knows what to do, for instance, try to parse the response into User
models.
This enables us to stay concise without having to write extra code. \o/
Note: ws
uses then
for Promises
https://github.com/freshOS/then
Get it!
voidCall().then {
print("done")
}
jsonCall().then { json in
print(json)
}
singleModelCall().then { user in
print(user) // Strongly typed User \o/
}
modelArrayCall().then { users in
print(users) // Strongly typed [User] \o/
}
Settings
Want to log all network calls and responses?
ws.logLevels = .debug
Want to hide network activity indicator?
ws.showsNetworkActivityIndicator = false
Want to override the default session manager to customize trust policies?
import Alamofire
ws.sessionManager = SessionManager(serverTrustPolicyManager: ServerTrustPolicyManager(
policies: ["myspecialhostname.com" : .disableEvaluation]
))
Api Example
Here is a Typical CRUD example for Articles :
extension Article {
static func list() -> Promise<[Article]> {
return ws.get("/articles")
}
func save() -> Promise<Article> {
return ws.post("/articles", params: ["name":name])
}
func fetch() -> Promise<Article> {
return ws.get("/articles/\(id)")
}
func update() -> Promise<Void> {
return ws.put("/articles/\(id)", params: ["name":name])
}
func delete() -> Promise<Void> {
return ws.delete("/articles/\(id)")
}
}
Here is how we use it in code :
// List Articles
Article.list().then { articles in
}
// Create Article
var newArticle = Article(name:"Cool story")
newArticle.save().then { createdArticle in
}
// Fetch Article
var existingArticle = Article(id:42)
existingArticle.fetch().then { fetchedArticle in
}
// Edit Article
existingArticle.name = "My new name"
existingArticle.update().then {
}
// Delete Article
existingArticle.delete().then {
}
HTTP Status code
When a request fails, we often want to know the reason thanks to the HTTP status code. Here is how to get it :
ws.get("/users").then {
// Do something
}.onError { e in
if let wsError = e as? WSError {
print(wsError.status)
print(wsError.status.rawValue) // RawValue for Int status
}
}
You can find the full WSError
enum here -> https://github.com/freshOS/ws/blob/master/ws/WSError.swift
Bonus - Load More pattern
Very often we deal we lists and the ability to load more
items.
Here we are going to see an example implementation of this pattern using ws
.
This is not included because the logic itself depends on your backend implementation.
This will give you an example for you to roll out your own version.
Implementation
import ws
import then
import Arrow
class LoadMoreRequest<T:ArrowParsable> {
var limit = 12
private var params = [String:Any]()
private var offset = 0
private var call: WSRequest!
private var canLoadMore = true
private var aCallback:((_ ts: [T]) -> [T])? = nil
init(_ aCall: WSRequest) {
call = aCall
}
func resetOffset() {
offset = 0
canLoadMore = true
}
func hasMoreItemsToload() -> Bool {
return canLoadMore
}
func fetchNext() -> Promise<[T]> {
params = call.params
params["limit"] = limit
params["offset"] = offset
call.params = params
offset += limit
return call.fetch()
.registerThen(parseModels)
.resolveOnMainThread()
}
private func parseModels(_ json: JSON) -> [T] {
let mapper = WSModelJSONParser<T>()
let models = mapper.toModels(json)
if models.count < limit {
canLoadMore = false
}
return models
}
}
As you can see, we have a strongly typed request.
The limit is adjustable.
It encapsulates a WSRequest.
It handles the offset logic and also wether or not there are more items to load.
And that's all we need!
Now, this is how we build a LoadMoreRequest
func loadMoreUsersRequest() -> LoadMoreRequest<User> {
return LoadMoreRequest(ws.getRequest("/users"))
}
Usage
And here is how we use it in our controllers :
class ViewController: UIViewController {
// Get a request
let request = api.loadMoreUsersRequest()
override func viewDidLoad() {
super.viewDidLoad()
request.limit = 5 // Set a limit if needed
}
func refresh() {
// Resets the request, usually plugged with
// the pull to refresh feature of a tableview
request.resetOffset()
}
func loadMore() {
// Get the next round of users
request.fetchNext().then { users in
print(users)
}
}
func shouldDisplayLoadMoreSpinner() -> Bool {
// This asks the requests if there are more items to come
// This is useful to know if we show the "load more" spinner
return request.hasMoreItemsToload()
}
}
Here you go you now have a simple way to deal with load more requests in your App
Bonus - Simplifying restful routes usage
When working with a RESTFUL
api, we can have fun and go a little further.
By introducing a RestResource
protocol
public protocol RestResource {
static func restName() -> String
func restId() -> String
}
We can have a function that builds our REST
URL
public func restURL<T:RestResource>(_ r:T) -> String {
return "/\(T.restName())/\(r.restId())"
}
We conform our User
Model to the protocol
extension User:RestResource {
static func restName() -> String { return "users" }
func restId() -> String { return "\(identifier)" }
}
And we can implement a version of get
that takes our a RestResource
public func get<T:ArrowParsable & RestResource>(_ restResource:T, params:[String:Any] = [String:Any]()) -> Promise<T> {
return get(restURL(restResource), params: params)
}
then
ws.get("/users/\(user.identifier)")
Can be written like :
ws.get(user)
Of course, the same logic can be applied to the all the other ws functions (post
, put
delete
etc) !
Installation
Swift Package Manager (SPM)
Due to the challenge of supporting all package manager at once, SPM support is availlable on a separate branch spm-only
.
Carthage
In your Cartfile
github "freshOS/ws"
- Run
carthage update
- Drag and drop
ws.framework
fromCarthage/Build/iOS
toLinked Frameworks and Libraries
(“General” settings tab) - Go to
Project
>Target
>Build Phases
+New run Script Phase
/usr/local/bin/carthage copy-frameworks
Add input files
$(SRCROOT)/Carthage/Build/iOS/ws.framework
$(SRCROOT)/Carthage/Build/iOS/Alamofire.framework
$(SRCROOT)/Carthage/Build/iOS/Arrow.framework
$(SRCROOT)/Carthage/Build/iOS/then.framework
This links ws and its dependencies.
Manually
Carthage is pretty useful since it takes care of pulling dependencies such as Arrow, then and Alamofire. What's cool is that it really is transparent. What I mean is that you could just use carthage on the side to pull and build dependencies and manually link frameworks to your Xcode project.
Without Carthage, I'd see 2 solutions : 1 - Copy paste all the source code : ws / then / Arrow / Alamofire which doesn't sound like a lot of fun ;) 2 - Manually link the frameworks (ws + dependencies) by A grabbing .frameworks them on each repo, or B use Carthage to build them
Cocoapods
target 'MyApp'
pod 'ws'
use_frameworks!
Swift Version
Swift 2 -> version 1.3.0
Swift 3 -> version 2.0.4
Swift 4 -> version 3.0.0
Swift 4.1 -> version 3.1.0
Swift 4.2 -> version 3.2.0
Swift 5.0 -> version 5.0.0
Swift 5.1 -> version 5.1.0
Swift 5.1.3 -> version 5.1.1
Backers
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Sponsors
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