Introducing SwiftHtml
This time we’ll begin every thing from scratch. Within the first part of this text I’ll present you tips on how to setup the SwiftHtml as a package deal dependency and tips on how to generate HTML output primarily based on a template file. Let’s begin by making a model new executable Swift package deal.
mkdir Instance
cd "$_"
swift package deal init --type=executable
open Bundle.swift
You can even begin with a macOS Command Line Software from Xcode if you want, however these days I want Swift Packages. Anyway, we should always add SwiftHtml as a dependency to our package deal straight away.
import PackageDescription
let package deal = Bundle(
identify: "Instance",
platforms: [
.macOS(.v12)
],
dependencies: [
.package(url: "https://github.com/binarybirds/swift-html", from: "1.2.0"),
],
targets: [
.executableTarget(name: "Example", dependencies: [
.product(name: "SwiftHtml", package: "swift-html"),
]),
.testTarget(identify: "ExampleTests", dependencies: ["Example"]),
]
)All proper, now we’re prepared to jot down some Swift DSL code. We will begin with a extremely primary instance to get to know with SwiftHtml. In the primary.swift file we should always create a brand new HTML doc, then we are able to use SwiftHtml’s built-in renderer to print the html supply. 🖨
import SwiftHtml
let doc = Doc(.html) {
Html {
Head {
Title("Hi there, World!")
Meta().charset("utf-8")
Meta().identify(.viewport).content material("width=device-width, initial-scale=1")
}
Physique {
Principal {
Div {
H1("Hi there, World!")
P("This web page was generated by the SwiftHtml library.")
}
}
.class("container")
}
}
}
let html = DocumentRenderer(minify: false, indent: 2).render(doc)
print(html)As you possibly can see the code is fairly easy, particularly if you recognize a bit about HTML. The SwiftHtml library tries to observe the naming conventions as intently as attainable, so when you’ve written HTML earlier than this syntax must be very acquainted, besides that you do not have to jot down opening and shutting tags, however we are able to make the most of the Swift compiler to do the boring repetative duties as a substitute of us.
Since we’re utilizing a site particular language in Swift, the compiler can type-check every thing at build-time, this fashion it is 100% positive that our HTML code will not have syntax points. In fact you possibly can nonetheless make semantic errors, however that is additionally attainable when you’re not utilizing a DSL. 😅
The principle benefit right here is that you just will not be capable of mistype or misspell tags, and you do not even have to consider closing tags, however you should utilize end result builders to assemble the HTML node tree. SwiftHtml makes use of tags and it will construct a tree from them, this fashion it’s attainable to effectively render all the construction with correct indentation or minification whether it is wanted.
The DocumentRenderer object can render a doc, it’s also attainable to create all types of SGML-based doc sorts, as a result of the SwiftHtml package deal comes with an abstraction layer. In the event you check out the package deal construction it is best to see that contained in the Sources listing there are a number of different directories, the core of the package deal is the SwiftSgml part, which permits builders to create different area particular languages on high of the bottom parts. 🤔 For instance, when you check out the SwiftRss package deal you will note that it is a easy extension over the SwiftSgml library. You’ll be able to subclass the Tag object to create a brand new (area particular) tag with an underlying Node object to signify a customized merchandise to your doc.
The SwiftSgml library may be very light-weight. The Node struct is a illustration of a given SGML node with a customized sort, identify and attributes. The Tag class is all about constructing a hierarchy in between the nodes. The Doc struct is a particular object which is liable for rendering the doctype declaration earlier than the basis tag if wanted, additionally after all the doc accommodates the basis tag, which is the start of every thing. 😅
SwiftSgml additionally accommodates the DocumentRenderer and a easy TagBuilder enum, which is a end result builder and it permits us to outline our construction in a SwiftUI-like fashion.
So the SwiftHtml package deal is only a set of HTML guidelines on high of the SwiftSgml library and it follows the W3C HTML reference guides. You should use the output string to save lots of a HTML file, this fashion you possibly can generate static web sites through the use of the SwiftHtml library.
import Basis
import SwiftHtml
let doc = Doc(.html) {
Html {
Head {
Title("Hi there, World!")
Meta().charset("utf-8")
Meta().identify(.viewport).content material("width=device-width, initial-scale=1")
}
Physique {
Principal {
Div {
H1("Hi there, World!")
P("This web page was generated by the SwiftHtml library.")
}
}
.class("container")
}
}
}
do {
let dir = FileManager.default.homeDirectoryForCurrentUser
let file = dir.appendingPathComponent("index.html")
let html = DocumentRenderer(minify: false, indent: 2).render(doc)
attempt html.write(to: file, atomically: true, encoding: .utf8)
}
catch {
fatalError(error.localizedDescription)
}This is only one method to make use of SwiftHtml, for my part static web site mills are tremendous, however the true enjoyable begins when you possibly can render web sites primarily based on some sort of dynamic knowledge. 🙃
Utilizing SwiftHtml with Vapor
Vapor has an official template engine referred to as Leaf plus the group additionally created a type-safe HTML DSL library referred to as HTMLKit, so why create one thing very comparable?
Effectively, I attempted all of the accessible Swift HTML DSL libraries that I used to be capable of finding on GitHub, however I used to be not solely happy with the at the moment accessible options. Lots of them was outdated, incomplete or I merely did not like the flavour of the DSL. I needed to have a library which is freakin’ light-weight and follows the requirements, that is the rationale why I’ve constructed SwiftHtml. 🤐
How can we combine SwiftHtml with Vapor? Effectively, it is fairly easy, let’s add Vapor as a dependency to our venture first.
import PackageDescription
let package deal = Bundle(
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"]),
]
)We will want a brand new protocol, which we are able to use assemble a Tag, that is going to signify a template file, so let’s name it TemplateRepresentable.
import Vapor
import SwiftSgml
public protocol TemplateRepresentable {
@TagBuilder
func render(_ req: Request) -> Tag
}Subsequent, we’d like one thing that may render a template file and return with a Response object, that we are able to use inside a request handler after we setup the route handlers in Vapor. Since we’ll return a HTML string, it’s essential to set the correct response headers too.
import Vapor
import SwiftHtml
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))
}
}Lastly we are able to prolong the built-in Request object to return a brand new template renderer if we’d like it.
import Vapor
public extension Request {
var templates: TemplateRenderer { .init(self) }
}Now we simply need to create a HTML template file. I am normally making a context object proper subsequent to the template this fashion I am going to have the ability to cross round contextual variables for every template file. I am fairly proud of this strategy to date. ☺️
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 {
Principal {
Div {
H1(context.title)
P(context.message)
}
}
.class("container")
}
}
}
}Lastly we simply have to jot down some boilerplate code to start out up our Vapor net server, we are able to use the app occasion and set a get request handler and render our template utilizing the newly created template renderer extension on the Request object.
import Vapor
import SwiftHtml
var env = attempt Surroundings.detect()
attempt LoggingSystem.bootstrap(from: &env)
let app = Utility(env)
defer { app.shutdown() }
app.get { req -> Response in
let template = IndexTemplate(.init(title: "Hi there, World!",
message: "This web page was generated by the SwiftHtml library."))
return req.templates.renderHtml(template)
}
attempt app.run()Roughly that is it, it is best to be capable of run the server and hopefully it is best to see the rendered HTML doc when you open the http://localhost:8080/ handle utilizing your browser.
Additionally it is attainable to make use of one template inside one other, since you possibly can name the render technique on a template and that template will return a Tag. The fantastic thing about this strategy is which you can compose smaller templates collectively, this fashion you possibly can provide you with a pleasant venture construction with reusable HTML templates written solely in Swift. I am very happy with this straightforward resolution and looks as if, for me, there is no such thing as a turning again to Leaf or Tau… 🤓
