The right way to make a PWA for iOS?
A progressive net utility is only a particular type of web site, that may look and behave like a local iOS app. To be able to construct a PWA, first we will create an everyday web site utilizing SwiftHtml. We are able to begin with an everyday executable Swift package deal with the next dependencies.
import PackageDescription
let package deal = Bundle(
title: "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(title: "ExampleTests", dependencies: ["Example"]),
]
)As you possibly can see we will use the vapor Vapor library to serve our HTML website. 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 aspect Swift functions, it is a fairly wonderful software I’ve a newbie’s information put up about it.
In fact we will want some elements for rendering views utilizing SwiftHtml, you should 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. You must 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 principal HTML doc. Since we’re utilizing a Swift DSL to jot 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 keep up a totally 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().title(.viewport).content material("width=device-width, initial-scale=1")
}
Physique {
Foremost {
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 primary entry level of our Swift package deal through the use of the beforehand outlined template helper strategies on the Request object.
import Vapor
import SwiftHtml
var env = attempt Setting.detect()
attempt LoggingSystem.bootstrap(from: &env)
let app = Software(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)
}
attempt app.run()It’s simply that simple to setup and bootstrap a completely working net server that’s able to rendering a HTML doc utilizing the ability of Swift and the Vapor framework. If you happen to run the app you must have the ability to see a working web site by visiting the http://localhost:8080/ handle.
Turning an internet site into an actual iOS PWA
Now if we wish to remodel our web site right into a standalone PWA, we have now to offer a hyperlink a particular net app manifest file inside the top part of the index template.
Meta tags vs manifest.json
Looks like Apple follows type of a wierd route if it involves PWA assist. They’ve fairly a historical past of “considering exterior of the field”, this mindset applies to progressive net apps on iOS, since they do not are likely to comply with the requirements in any respect. For Android units you might create a manifest.json file with some predefined keys and you would be simply superb along with your PWA. However Apple these days prefers varied HTML meta tags as a substitute of the net manifest format.
Personally I do not like this method, as a result of your HTML code will likely 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 type of issues, however hey it is Apple, they cannot be flawed, proper? 😅
Anyhow, let me present you assist varied PWA options on iOS.
Enabling standalone app mode
The very first few keys that we might like so as to add to the index template has the apple-mobile-web-app-capable title and you must use the “sure” string as content material. This can point out that the app ought to run in full-screen mode, in any other case it is going to be displayed utilizing Safari similar to an everyday website.
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().title(.viewport).content material("width=device-width, initial-scale=1")
Meta()
.title(.appleMobileWebAppCapable)
.content material("sure")
}
Physique {
Foremost {
Div {
H1(context.title)
P(context.message)
}
}
}
}
}
}We should always change the hostname of the server and hear on the 0.0.0.0 handle, this fashion in case your cellphone is on the identical native WiFi community you must have the ability to attain your net server straight.
import Vapor
import SwiftHtml
var env = attempt Setting.detect()
attempt LoggingSystem.bootstrap(from: &env)
let app = Software(env)
defer { app.shutdown() }
app.http.server.configuration.hostname = "0.0.0.0"
if let hostname = Setting.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)
}
attempt app.run()You’ll find out your native IP handle by typing the next command into the Terminal app.
# utilizing ifconfig & grep
ifconfig | grep -Eo 'inet (addr:)?([0-9]*.){3}[0-9]*' | grep -Eo '([0-9]*.){3}[0-9]*' | grep -v '127.0.0.1'
# utilizing ifconfig & sed
ifconfig | sed -En 's/127.0.0.1//;s/.*inet (addr:)?(([0-9]*.){3}[0-9]*).*/2/p'
Simply use that IP handle and go to the http://[ip-address]:8080/ web site utilizing your iOS gadget, then you must have the ability to add your web site to your house display screen as a bookmark. Simply faucet the Share icon utilizing Safari and choose the Add to House Display screen menu merchandise from the record. On the brand new display screen faucet the Add button on the highest proper nook, it will create a brand new icon on your house display screen as a bookmark to your web page. Optionally, you possibly can present a customized title 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). In fact 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 title and icon
To supply a customized title we simply have so as to add a brand new meta tag, luckily 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().title(.viewport).content material("width=device-width, initial-scale=1")
Meta()
.title(.appleMobileWebAppCapable)
.content material("sure")
Meta()
.title(.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 {
Foremost {
Div {
H1(context.title)
P(context.message)
}
}
}
}
}
}As you possibly can see icons are referenced through the use of the Hyperlink tag, utilizing the Apple contact icon rel attribute. The default icon with out the sizes attribute could be a 192×192 pixel picture, plus I am offering some smaller sizes through the use of a for loop right here. We additionally must serve these icon information through the use of Vapor, that is why we will alter the configuration file and allow the FileFiddleware.
import Vapor
import SwiftHtml
var env = attempt Setting.detect()
attempt LoggingSystem.bootstrap(from: &env)
let app = Software(env)
defer { app.shutdown() }
app.middleware.use(FileMiddleware(publicDirectory: app.listing.publicDirectory))
app.http.server.configuration.hostname = "0.0.0.0"
if let hostname = Setting.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)
}
attempt 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. If you’re operating the server from the command line you may be superb, however in case you are utilizing Xcode you need to specify a customized working listing for Vapor, it will permit the system to lookup the general public information from the correct place.
Your customized icons will not present up in case you are utilizing a self-signed certificates.
Construct and run the server and attempt to bookmark your web page once more utilizing your cellphone. Once you see the add bookmark web page you must have the ability to validate that the app now makes use of the predefined Hiya PWA title and the picture preview ought to present the customized icon file as a substitute of a screenshot of the web page.
Correct standing bar colour for iOS PWAs
Lengthy story quick, there’s a nice article on CSS-Methods about the latest model of Safari and the way it handles varied theme colours on completely different platforms. It is an important article, you must positively learn it, however in a lot of the instances 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 colour and for darkish mode we use black. We’re additionally going to hyperlink a brand new model.css file so we will change the background of the positioning and the font colour in keeping with the present colour 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().title(.viewport).content material("width=device-width, initial-scale=1")
Meta()
.title(.appleMobileWebAppCapable)
.content material("sure")
Meta()
.title(.appleMobileWebAppTitle)
.content material("Hiya PWA")
Meta()
.title(.colorScheme)
.content material("mild darkish")
Meta()
.title(.themeColor)
.content material("#fff")
.media(.prefersColorScheme(.mild))
Meta()
.title(.themeColor)
.content material("#000")
.media(.prefersColorScheme(.darkish))
Hyperlink(rel: .stylesheet)
.href("/css/model.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 {
Foremost {
Div {
H1(context.title)
P(context.message)
}
}
}
}
}
}Contained in the model CSS file we will use a media question to detect the popular colour scheme, similar to we did it for the .themeColor meta tag utilizing SwiftHtml.
physique {
background: #fff;
colour: #000;
}
@media (prefers-color-scheme: darkish) {
physique {
background: #000;
colour: #fff;
}
}
That is it, now the standing bar ought to use the identical colour as your principal background. Attempt to swap between darkish and light-weight mode and ensure every part works, there’s a cool PWA demo challenge right here with completely 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 flawed splash display screen or will not render PNG information correctly, now if it involves PWAs this is not crucial higher. I used to be capable of present splash display screen pictures for my app, nevertheless it took me fairly some time and switching between darkish and light-weight mode is completely damaged (so far as I do know it). 😅
To be able to cowl each single gadget display screen dimension, you need to add plenty 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,
_ top: Int,
_ ratio: Int,
_ orientation: MediaQuery.Orientation) -> Tag {
splashTag(.mild, width, top, ratio, orientation)
splashTag(.darkish, width, top, ratio, orientation)
}
func splashTag(_ mode: MediaQuery.ColorScheme,
_ width: Int,
_ top: 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, top, ratio, orientation))(mode == .mild ? "" : "_dark").png")
}
func calc(_ width: Int,
_ top: Int,
_ ratio: Int,
_ orientation: MediaQuery.Orientation) -> String {
let w = String(width * ratio)
let h = String(top * 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 top part, however I am unsure if the result’s one thing I can completely agree with. Right here, check out the tip 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 completely different picture information that you’re going to want. Individuals are actually utilizing PWA asset turbines to scale back the time wanted to generate these type of photos, as a result of it is fairly uncontrolled. 💩
Secure space & the notch
A particular matter I would like to speak about is the secure space assist and the notch. I can extremely suggest to learn this text on CSS-Methods about The Notch and CSS first, however the primary trick is that we will use 4 environmental variables in CSS to set correct margin and padding values.
First we have now to vary the viewport meta tag and lengthen our web page past the secure space. This may be executed through the use of 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()
.title(.viewport)
.content material("width=device-width, initial-scale=1, viewport-fit=cowl")
Meta()
.title(.appleMobileWebAppCapable)
.content material("sure")
Meta()
.title(.appleMobileWebAppTitle)
.content material("Hiya PWA")
Meta()
.title(.colorScheme)
.content material("mild darkish")
Meta()
.title(.themeColor)
.content material("#fff")
.media(.prefersColorScheme(.mild))
Meta()
.title(.themeColor)
.content material("#000")
.media(.prefersColorScheme(.darkish))
Hyperlink(rel: .stylesheet)
.href("/css/model.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")
}
Foremost {
Div {
Div {
H1(context.title)
for _ in 0...42 {
P(context.message)
}
A("Refresh web page")
.href("/")
}
.class("wrapper")
}
.class("safe-area")
}
Footer {
Div {
P("Footer space")
}
.class("safe-area")
}
}
}
}
}Besides the background colour we do not need different content material to stream exterior the secure space, so we will outline a brand new CSS class and place some margins on it primarily based on the atmosphere. Additionally we can safely use the calc CSS perform if we wish to add some additional worth to the atmosphere.
* {
margin: 0;
padding: 0;
}
physique {
background: #fff;
colour: #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;
colour: #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 need to 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 should use the display-mode selector to examine if the app is operating 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;
prime: 0;
border-bottom: 1px stable #eee;
}
}
@media (display-mode: standalone) and (prefers-color-scheme: darkish) {
header, footer {
background: #000;
}
header {
border-bottom: 1px stable #333;
}
}
You possibly can flip the header right into a sticky part through the use of the place: sticky attribute. I often favor to comply with the iOS model when the web site is introduced to the end-user as a standalone app and I maintain the unique theme colours for the net solely.
Remember to rebuild the backend server, earlier than you check your app. Since we have made some meta modifications you might need to delete the PWA bookmark and set up it once more to make issues work. ⚠️
As you possibly can see constructing handsome progressive net apps for iOS is kind of difficult, particularly if it involves the metadata insanity that Apple created. Anyway, I hope this tutorial will provide help to to construct higher PWAs for the iOS platform. That is simply the tip of the iceberg, we’ve not talked about JavaScript in any respect, however perhaps I am going to come again with that matter in a brand new tutorial in a while.