Easy methods 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. As a way to construct a PWA, first we will create a daily web site utilizing SwiftHtml. We are able to begin with a daily executable Swift bundle with the next dependencies.
import PackageDescription
let bundle = Package deal(
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 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 wonderful device 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 seem like. It’s 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 important 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 are able to 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 bundle 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 = Software(env)
defer { app.shutdown() }
app.get { req -> Response in
let template = IndexTemplate(.init(title: "Howdy, 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 case you run the app it’s best to have the ability to see a working web site by visiting the http://localhost:8080/ tackle.
Turning an internet site into an actual iOS PWA
Now if we wish to remodel our web site right into a standalone PWA, we now have to offer a hyperlink a particular net app manifest file inside the pinnacle part of the index template.
Meta tags vs manifest.json
Looks like Apple follows sort of an odd 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 positive together with your PWA. Alternatively Apple these days prefers varied HTML meta tags as a substitute of the online manifest format.
Personally I do not like this strategy, as a result of your HTML code might be bloated with all of the PWA associated stuff (as you may see that is going to occur if it involves launch display screen photographs) and I consider it is higher to separate these sort of issues, however hey it is Apple, they can not be fallacious, proper? 😅
In any case, let me present you the right way to 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 it’s best to 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 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().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 pay attention on the 0.0.0.0 tackle, this manner in case your cellphone is on the identical native WiFi community it’s best to have the ability to attain your net server immediately.
import Vapor
import SwiftHtml
var env = strive Surroundings.detect()
strive LoggingSystem.bootstrap(from: &env)
let app = Software(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: "Howdy, World!",
message: "This web page was generated by the SwiftHtml library."))
return req.templates.renderHtml(template)
}
strive app.run()
You could 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 system, then it’s best to have the ability to add your web site to your private home display screen as a bookmark. Simply faucet the Share icon utilizing Safari and choose the Add to House Display menu merchandise from the checklist. On the brand new display screen faucet the Add button on the highest proper nook, this can create a brand new icon on your private home 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, when you 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 internet 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 offer a customized title we simply have so as to add a brand new meta tag, thankfully 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 state of affairs is a little more tough, since we now have 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("Howdy 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 by utilizing 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 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 = 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 = Surroundings.get("SERVER_HOSTNAME") {
app.http.server.configuration.hostname = hostname
}
app.get { req -> Response in
let template = IndexTemplate(.init(title: "Howdy, 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 at liberty to create it and place the app icons below the Public/img/apple/icons folder. In case you are operating the server from the command line you may be positive, however if you’re utilizing Xcode you need to specify a customized working listing for Vapor, this can enable the system to lookup the general public information from the precise 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 cellphone. Whenever you see the add bookmark web page it’s best to have the ability to validate that the app now makes use of the predefined Howdy 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 coloration for iOS PWAs
Lengthy story quick, there’s a nice article on CSS-Tips about the newest model of Safari and the way it handles varied theme colours on totally different platforms. It is an excellent article, it’s best to positively learn it, however in many of the instances you will not want this a lot information, however you merely wish to assist mild and darkish mode to your progressive net app. That is what I’ll present you right here.
For mild mode we will use a white background coloration and for darkish mode we use black. We’re additionally going to hyperlink a brand new model.css file so we are able to change the background of the positioning and the font coloration based on the present coloration 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("Howdy 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 are able to use a media question to detect the popular coloration scheme, similar to we did it for the .themeColor meta tag utilizing SwiftHtml.
physique {
background: #fff;
coloration: #000;
}
@media (prefers-color-scheme: darkish) {
physique {
background: #000;
coloration: #fff;
}
}
That is it, now the standing bar ought to use the identical coloration as your important 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 totally different colours for every mode if you wish to double verify 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 photographs for my app, but it surely took me fairly some time and switching between darkish and light-weight mode is completely damaged (so far as I do know it). 😅
As a way to cowl each single system display screen dimension, you need to add numerous linked splash photographs 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 informed you in regards to the 40 totally different picture information that you’re going to want. Persons are actually utilizing PWA asset mills to scale 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 proud of splash display screen assist, however hey, it simply works, proper? 🤔
Protected space & the notch
A particular subject I might like to speak about is the secure space assist and the notch. I can extremely suggest to learn this text on CSS-Tips about The Notch and CSS first, however the primary trick is that we are able to use 4 environmental variables in CSS to set correct margin and padding values.
First we now have to alter the viewport meta tag and prolong our web page past the secure space. This may be performed 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()
.title(.viewport)
.content material("width=device-width, initial-scale=1, viewport-fit=cowl")
Meta()
.title(.appleMobileWebAppCapable)
.content material("sure")
Meta()
.title(.appleMobileWebAppTitle)
.content material("Howdy 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("https://theswiftdev.com/")
}
.class("wrapper")
}
.class("safe-area")
}
Footer {
Div {
P("Footer space")
}
.class("safe-area")
}
}
}
}
}
Besides the background coloration we do not need different content material to movement exterior the secure space, so we are able to outline a brand new CSS class and place some margins on it based mostly on the surroundings. Additionally we can safely use the calc CSS perform if we wish to add some additional worth to the surroundings.
* {
margin: 0;
padding: 0;
}
physique {
background: #fff;
coloration: #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;
coloration: #fff;
}
header {
background: #222;
}
footer {
background: #222;
}
}
It seems to be good, however what if we might like to make use of customized types for the PWA model solely?
Detecting standalone mode
If you wish to use the show mode media question in your CSS file we now have 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 verify if the app runs in a standalone mode you may need to create an internet 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 verify 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;
high: 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 may flip the header right into a sticky part by utilizing the place: sticky attribute. I often choose to comply with the iOS model when the web site is offered to the end-user as a standalone app and I maintain the unique theme colours for the online solely.
Remember to rebuild the backend server, earlier than you take a look at 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. ⚠️
