Find out how to make a PWA for iOS?
A progressive net utility is only a particular sort of web site, that may look and behave like a local iOS app. So as to construct a PWA, first we will create a daily web site utilizing SwiftHtml. We will begin with a daily executable Swift package deal with the next dependencies.
import PackageDescription
let package deal = Package deal(
identify: "Instance",
platforms: [
.macOS(.v12)
],
dependencies: [
.package(url: "https://github.com/binarybirds/swift-html", from: "1.2.0"),
.package(url: "https://github.com/vapor/vapor", from: "4.54.0"),
],
targets: [
.executableTarget(name: "Example", dependencies: [
.product(name: "SwiftHtml", package: "swift-html"),
.product(name: "Vapor", package: "vapor"),
]),
.testTarget(identify: "ExampleTests", dependencies: ["Example"]),
]
)
As you possibly can see we will use the vapor Vapor library to serve our HTML web site. If you do not know a lot about Vapor let’s simply say that it’s a net utility framework, which can be utilized to construct server facet Swift purposes, it is a fairly superb software I’ve a newbie’s information submit about it.
After all we will want some elements for rendering views utilizing SwiftHtml, you need to use the supply snippets from my earlier article, however right here it’s once more how the SwiftHtml-based template engine ought to appear like. It is best to learn my different article if you wish to know extra about it. 🤓
import Vapor
import SwiftSgml
public protocol TemplateRepresentable {
@TagBuilder
func render(_ req: Request) -> Tag
}
public struct TemplateRenderer {
var req: Request
init(_ req: Request) {
self.req = req
}
public func renderHtml(_ template: TemplateRepresentable, minify: Bool = false, indent: Int = 4) -> Response {
let doc = Doc(.html) { template.render(req) }
let physique = DocumentRenderer(minify: minify, indent: indent).render(doc)
return Response(standing: .okay, headers: ["content-type": "text/html"], physique: .init(string: physique))
}
}
public extension Request {
var templates: TemplateRenderer { .init(self) }
}
We’re additionally going to want an index template for our fundamental HTML doc. Since we’re utilizing a Swift DSL to write down HTML code we do not have to fret an excessive amount of about mistyping a tag, the compiler will defend us and helps to take care of a very legitimate HTML construction.
import Vapor
import SwiftHtml
struct IndexContext {
let title: String
let message: String
}
struct IndexTemplate: TemplateRepresentable {
let context: IndexContext
init(_ context: IndexContext) {
self.context = context
}
func render(_ req: Request) -> Tag {
Html {
Head {
Title(context.title)
Meta().charset("utf-8")
Meta().identify(.viewport).content material("width=device-width, initial-scale=1")
}
Physique {
Predominant {
Div {
H1(context.title)
P(context.message)
}
}
}
}
}
}
Lastly we will merely render the bootstrap our Vapor server occasion, register our route handler and render the index template inside the principle entry level of our Swift package deal by utilizing the beforehand outlined template helper strategies on the Request object.
import Vapor
import SwiftHtml
var env = strive Surroundings.detect()
strive LoggingSystem.bootstrap(from: &env)
let app = Utility(env)
defer { app.shutdown() }
app.get { req -> Response in
let template = IndexTemplate(.init(title: "Hiya, World!",
message: "This web page was generated by the SwiftHtml library."))
return req.templates.renderHtml(template)
}
strive app.run()
It’s simply that straightforward to setup and bootstrap a completely working net server that’s able to rendering a HTML doc utilizing the facility of Swift and the Vapor framework. In the event you run the app you need to have the ability to see a working web site by visiting the http://localhost:8080/ tackle.
Turning a web site into an actual iOS PWA
Now if we wish to rework our web site right into a standalone PWA, we have now to supply a hyperlink a particular net app manifest file inside the pinnacle part of the index template.
Meta tags vs manifest.json
Looks as if Apple follows sort of a wierd route if it involves PWA assist. They’ve fairly a historical past of “pondering exterior of the field”, this mindset applies to progressive net apps on iOS, since they do not are likely to observe the requirements in any respect. For Android units you could possibly create a manifest.json file with some predefined keys and you would be simply tremendous along with your PWA. Then again Apple these days prefers numerous HTML meta tags as a substitute of the online manifest format.
Personally I do not like this method, as a result of your HTML code will probably be bloated with all of the PWA associated stuff (as you may see that is going to occur if it involves launch display screen pictures) and I imagine it is higher to separate these sort of issues, however hey it is Apple, they cannot be fallacious, proper? 😅
Anyhow, let me present you how one can assist numerous PWA options on iOS.
Enabling standalone app mode
The very first few keys that we would like so as to add to the index template has the apple-mobile-web-app-capable identify and you need to use the “sure” string as content material. It will point out that the app ought to run in full-screen mode, in any other case it is going to be displayed utilizing Safari identical to a daily web site.
struct IndexTemplate: TemplateRepresentable {
let context: IndexContext
init(_ context: IndexContext) {
self.context = context
}
func render(_ req: Request) -> Tag {
Html {
Head {
Title(context.title)
Meta().charset("utf-8")
Meta().identify(.viewport).content material("width=device-width, initial-scale=1")
Meta()
.identify(.appleMobileWebAppCapable)
.content material("sure")
}
Physique {
Predominant {
Div {
H1(context.title)
P(context.message)
}
}
}
}
}
}
We should always change the hostname of the server and pay attention on the 0.0.0.0 tackle, this fashion in case your telephone is on the identical native WiFi community you need to have the ability to attain your net server instantly.
import Vapor
import SwiftHtml
var env = strive Surroundings.detect()
strive LoggingSystem.bootstrap(from: &env)
let app = Utility(env)
defer { app.shutdown() }
app.http.server.configuration.hostname = "0.0.0.0"
if let hostname = Surroundings.get("SERVER_HOSTNAME") {
app.http.server.configuration.hostname = hostname
}
app.get { req -> Response in
let template = IndexTemplate(.init(title: "Hiya, World!",
message: "This web page was generated by the SwiftHtml library."))
return req.templates.renderHtml(template)
}
strive app.run()
You’ll find out your native IP tackle by typing the next command into the Terminal app.
ifconfig | grep -Eo 'inet (addr:)?([0-9]*.){3}[0-9]*' | grep -Eo '([0-9]*.){3}[0-9]*' | grep -v '127.0.0.1'
ifconfig | sed -En 's/127.0.0.1//;s/.*inet (addr:)?(([0-9]*.){3}[0-9]*).*/2/p'
Simply use that IP tackle and go to the http://[ip-address]:8080/ web site utilizing your iOS gadget, then you need to have the ability to add your web site to your own home display screen as a bookmark. Simply faucet the Share icon utilizing Safari and choose the Add to Residence Display menu merchandise from the listing. On the brand new display screen faucet the Add button on the highest proper nook, this can create a brand new icon on your own home display screen as a bookmark to your web page. Optionally, you possibly can present a customized identify for the bookmark. ☺️
Since we have added the meta tag, for those who contact the newly created icon it ought to open the webpage as a standalone app (with out utilizing the browser). After all the app continues to be only a web site rendered utilizing an online view. The standing bar will not match the white background and it has no customized icon or splash display screen but, however we will repair these points proper now. 📱
Customized identify and icon
To supply a customized identify we simply have so as to add a brand new meta tag, fortuitously the SwiftHtml library has predefined enums for all of the Apple associated meta names, so you do not have to kind that a lot. The icon scenario is a little more troublesome, since we have now so as to add a bunch of dimension variants.
struct IndexTemplate: TemplateRepresentable {
let context: IndexContext
init(_ context: IndexContext) {
self.context = context
}
func render(_ req: Request) -> Tag {
Html {
Head {
Title(context.title)
Meta().charset("utf-8")
Meta().identify(.viewport).content material("width=device-width, initial-scale=1")
Meta()
.identify(.appleMobileWebAppCapable)
.content material("sure")
Meta()
.identify(.appleMobileWebAppTitle)
.content material("Hiya PWA")
Hyperlink(rel: .appleTouchIcon)
.href("/img/apple/icons/192.png")
for dimension in [57, 72, 76, 114, 120, 144, 152, 180] {
Hyperlink(rel: .appleTouchIcon)
.sizes("(dimension)x(dimension)")
.href("/img/apple/icons/(dimension).png")
}
}
Physique {
Predominant {
Div {
H1(context.title)
P(context.message)
}
}
}
}
}
}
As you possibly can see icons are referenced by utilizing the Hyperlink tag, utilizing the Apple contact icon rel attribute. The default icon with out the sizes attribute generally is a 192×192 pixel picture, plus I am offering some smaller sizes by utilizing a for loop right here. We additionally must serve these icon information by utilizing Vapor, that is why we will alter the configuration file and allow the FileFiddleware.
import Vapor
import SwiftHtml
var env = strive Surroundings.detect()
strive LoggingSystem.bootstrap(from: &env)
let app = Utility(env)
defer { app.shutdown() }
app.middleware.use(FileMiddleware(publicDirectory: app.listing.publicDirectory))
app.http.server.configuration.hostname = "0.0.0.0"
if let hostname = Surroundings.get("SERVER_HOSTNAME") {
app.http.server.configuration.hostname = hostname
}
app.get { req -> Response in
let template = IndexTemplate(.init(title: "Hiya, World!",
message: "This web page was generated by the SwiftHtml library."))
return req.templates.renderHtml(template)
}
strive app.run()
By including the FileMiddleware to the app with the general public listing path configuration your server app is ready to serve static information from the Public listing. Be happy to create it and place the app icons beneath the Public/img/apple/icons folder. In case you are working the server from the command line you may be tremendous, however if you’re utilizing Xcode you need to specify a customized working listing for Vapor, this can permit the system to lookup the general public information from the suitable place.
Your customized icons will not present up if you’re utilizing a self-signed certificates.
Construct and run the server and attempt to bookmark your web page once more utilizing your telephone. If you see the add bookmark web page you need to have the ability to validate that the app now makes use of the predefined Hiya PWA identify and the picture preview ought to present the customized icon file as a substitute of a screenshot of the web page.
Correct standing bar shade for iOS PWAs
Lengthy story brief, there’s a nice article on CSS-Methods about the latest model of Safari and the way it handles numerous theme colours on totally different platforms. It is an ideal article, you need to positively learn it, however in a lot of the circumstances you will not want this a lot data, however you merely wish to assist mild and darkish mode in your progressive net app. That is what I will present you right here.
For mild mode we will use a white background shade and for darkish mode we use black. We’re additionally going to hyperlink a brand new fashion.css file so we will change the background of the location and the font shade in keeping with the present shade scheme. First, the brand new meta tags to assist theme colours each for mild and darkish mode.
struct IndexTemplate: TemplateRepresentable {
let context: IndexContext
init(_ context: IndexContext) {
self.context = context
}
func render(_ req: Request) -> Tag {
Html {
Head {
Title(context.title)
Meta().charset("utf-8")
Meta().identify(.viewport).content material("width=device-width, initial-scale=1")
Meta()
.identify(.appleMobileWebAppCapable)
.content material("sure")
Meta()
.identify(.appleMobileWebAppTitle)
.content material("Hiya PWA")
Meta()
.identify(.colorScheme)
.content material("mild darkish")
Meta()
.identify(.themeColor)
.content material("#fff")
.media(.prefersColorScheme(.mild))
Meta()
.identify(.themeColor)
.content material("#000")
.media(.prefersColorScheme(.darkish))
Hyperlink(rel: .stylesheet)
.href("/css/fashion.css")
Hyperlink(rel: .appleTouchIcon)
.href("/img/apple/icons/192.png")
for dimension in [57, 72, 76, 114, 120, 144, 152, 180] {
Hyperlink(rel: .appleTouchIcon)
.sizes("(dimension)x(dimension)")
.href("/img/apple/icons/(dimension).png")
}
}
Physique {
Predominant {
Div {
H1(context.title)
P(context.message)
}
}
}
}
}
}
Contained in the fashion CSS file we will use a media question to detect the popular shade scheme, identical to we did it for the .themeColor meta tag utilizing SwiftHtml.
physique {
background: #fff;
shade: #000;
}
@media (prefers-color-scheme: darkish) {
physique {
background: #000;
shade: #fff;
}
}
That is it, now the standing bar ought to use the identical shade as your fundamental background. Attempt to swap between darkish and lightweight mode and ensure every little thing works, there’s a cool PWA demo mission right here with totally different colours for every mode if you wish to double examine the code. ✅
Splash display screen assist
Trace: it is ridiculous. Splash screens on iOS are problematic. Even native apps are likely to cache the fallacious splash display screen or will not render PNG information correctly, now if it involves PWAs this is not obligatory higher. I used to be in a position to present splash display screen pictures for my app, nevertheless it took me fairly some time and switching between darkish and lightweight mode is completely damaged (so far as I do know it). 😅
So as to cowl each single gadget display screen dimension, you need to add a lot of linked splash pictures to your markup. It is so ugly I even needed to create a bunch of extension strategies to my index template.
extension IndexTemplate {
@TagBuilder
func splashTags() -> [Tag] {
splash(320, 568, 2, .panorama)
splash(320, 568, 2, .portrait)
splash(414, 896, 3, .panorama)
splash(414, 896, 2, .panorama)
splash(375, 812, 3, .portrait)
splash(414, 896, 2, .portrait)
splash(375, 812, 3, .panorama)
splash(414, 736, 3, .portrait)
splash(414, 736, 3, .panorama)
splash(375, 667, 2, .panorama)
splash(375, 667, 2, .portrait)
splash(1024, 1366, 2, .panorama)
splash(1024, 1366, 2, .portrait)
splash(834, 1194, 2, .panorama)
splash(834, 1194, 2, .portrait)
splash(834, 1112, 2, .panorama)
splash(414, 896, 3, .portrait)
splash(834, 1112, 2, .portrait)
splash(768, 1024, 2, .portrait)
splash(768, 1024, 2, .panorama)
}
@TagBuilder
func splash(_ width: Int,
_ peak: Int,
_ ratio: Int,
_ orientation: MediaQuery.Orientation) -> Tag {
splashTag(.mild, width, peak, ratio, orientation)
splashTag(.darkish, width, peak, ratio, orientation)
}
func splashTag(_ mode: MediaQuery.ColorScheme,
_ width: Int,
_ peak: Int,
_ ratio: Int,
_ orientation: MediaQuery.Orientation) -> Tag {
Hyperlink(rel: .appleTouchStartupImage)
.media([
.prefersColorScheme(mode),
.deviceWidth(px: width),
.deviceHeight(px: height),
.webkitDevicePixelRatio(ratio),
.orientation(orientation),
])
.href("/img/apple/splash/(calc(width, peak, ratio, orientation))(mode == .mild ? "" : "_dark").png")
}
func calc(_ width: Int,
_ peak: Int,
_ ratio: Int,
_ orientation: MediaQuery.Orientation) -> String {
let w = String(width * ratio)
let h = String(peak * ratio)
swap orientation {
case .portrait:
return w + "x" + h
case .panorama:
return h + "x" + w
}
}
}
Now I can merely add the splashTags() name into the pinnacle part, however I am unsure if the result’s one thing I can completely agree with. Right here, check out the top of this tutorial about splash screens, the code required to assist iOS splash screens could be very lengthy and I have never even instructed you concerning the 40 totally different picture information that you’re going to want. Individuals are actually utilizing PWA asset mills to cut back the time wanted to generate these sort of footage, as a result of it is fairly uncontrolled. 💩
I am utilizing this system in Feather CMS, so if you would like to obtain some pattern information you possibly can seize them from GitHub. I am not pleased with splash display screen assist, however hey, it simply works, proper? 🤔
Secure space & the notch
A particular matter I would like to speak about is the secure space assist and the notch. I can extremely advocate to learn this text on CSS-Methods about The Notch and CSS first, however the principle trick is that we will use 4 environmental variables in CSS to set correct margin and padding values.
First we have now to alter the viewport meta tag and lengthen our web page past the secure space. This may be completed by utilizing the viewport-fit cowl worth. Contained in the physique of the template we will add a header and a footer part, these areas can have customized background colours and fill the display screen.
struct IndexTemplate: TemplateRepresentable {
let context: IndexContext
init(_ context: IndexContext) {
self.context = context
}
func render(_ req: Request) -> Tag {
Html {
Head {
Title(context.title)
Meta()
.charset("utf-8")
Meta()
.identify(.viewport)
.content material("width=device-width, initial-scale=1, viewport-fit=cowl")
Meta()
.identify(.appleMobileWebAppCapable)
.content material("sure")
Meta()
.identify(.appleMobileWebAppTitle)
.content material("Hiya PWA")
Meta()
.identify(.colorScheme)
.content material("mild darkish")
Meta()
.identify(.themeColor)
.content material("#fff")
.media(.prefersColorScheme(.mild))
Meta()
.identify(.themeColor)
.content material("#000")
.media(.prefersColorScheme(.darkish))
Hyperlink(rel: .stylesheet)
.href("/css/fashion.css")
Hyperlink(rel: .appleTouchIcon)
.href("/img/apple/icons/192.png")
for dimension in [57, 72, 76, 114, 120, 144, 152, 180] {
Hyperlink(rel: .appleTouchIcon)
.sizes("(dimension)x(dimension)")
.href("/img/apple/icons/(dimension).png")
}
splashTags()
}
Physique {
Header {
Div {
P("Header space")
}
.class("safe-area")
}
Predominant {
Div {
Div {
H1(context.title)
for _ in 0...42 {
P(context.message)
}
A("Refresh web page")
.href("https://theswiftdev.com/")
}
.class("wrapper")
}
.class("safe-area")
}
Footer {
Div {
P("Footer space")
}
.class("safe-area")
}
}
}
}
}
Besides the background shade we do not need different content material to circulation exterior the secure space, so we will outline a brand new CSS class and place some margins on it primarily based on the setting. Additionally we can safely use the calc CSS perform if we wish to add some further worth to the setting.
* {
margin: 0;
padding: 0;
}
physique {
background: #fff;
shade: #000;
}
header, footer {
padding: 1rem;
}
header {
background: #eee;
}
footer {
background: #eee;
padding-bottom: calc(1rem + env(safe-area-inset-bottom));
}
.safe-area {
margin: 0 env(safe-area-inset-right) 0 env(safe-area-inset-left);
}
.wrapper {
padding: 1rem;
}
@media (prefers-color-scheme: darkish) {
physique {
background: #000;
shade: #fff;
}
header {
background: #222;
}
footer {
background: #222;
}
}
It seems to be good, however what if we might like to make use of customized kinds for the PWA model solely?
Detecting standalone mode
If you wish to use the show mode media question in your CSS file we have now so as to add a manifest file to our PWA. Yep, that is proper, I’ve talked about earlier than that Apple prefers to make use of meta tags and hyperlinks, however if you wish to use a CSS media question to examine if the app runs in a standalone mode you may should create an online manifest.json file with the next contents.
{
"show": "standalone"
}
Subsequent you need to present a hyperlink to the manifest file contained in the template file.
struct IndexTemplate: TemplateRepresentable {
func render(_ req: Request) -> Tag {
Html {
Head {
splashTags()
Hyperlink(rel: .manifest)
.href("/manifest.json")
}
Physique {
}
}
}
}
Within the CSS file now you need to use the display-mode selector to examine if the app is working in a standalone mode, you possibly can even mix these selectors and detect standalone mode and darkish mode utilizing a single question. Media queries are fairly helpful. 😍
/* ... */
@media (display-mode: standalone) {
header, footer {
background: #fff;
}
header {
place: sticky;
high: 0;
border-bottom: 1px strong #eee;
}
}
@media (display-mode: standalone) and (prefers-color-scheme: darkish) {
header, footer {
background: #000;
}
header {
border-bottom: 1px strong #333;
}
}
You’ll be able to flip the header right into a sticky part by utilizing the place: sticky attribute. I normally desire to observe the iOS fashion when the web site is offered to the end-user as a standalone app and I preserve the unique theme colours for the online solely.
Remember to rebuild the backend server, earlier than you check your app. Since we have made some meta adjustments you might need to delete the PWA bookmark and set up it once more to make issues work. ⚠️
