A blog exploring functional programming and Swift.

Announcing swift-html 0.2.0

Tuesday Jan 8, 2019

Today we’re releasing our first minor update to swift-html, a Swift DSL for type-safe, extensible, and transformable HTML documents. In fact, this very page was rendered with it!

We’ve been battle-testing this library for awhile now, long before its initial release last September. Today’s release contains a number of new features and fixes, including several patches from the community!

Support for new platforms and dependency managers

While we imagined swift-html to be most useful on the server with server-side Swift becoming more and more popular, a pull request let us know that there was interest in using our library on iOS, as well! With the help of the community we now support being embedded in your iOS, tvOS, and watchOS apps. Now you can render HTML in a type-safe manner just about anywhere!

We’ve also made installing swift-html on these platforms easier than ever by adding support for Carthage and CocoaPods. Check out the installation instructions to get started.

debugRender

We’ve added a new debugRender function that will render HTML nodes in a more human-readable format by indenting each node.

let doc = html([
  body([
    h1(["Welcome!"]),
    p(["You’ve found our site!"])
    ])
  ])

render(doc)
// <html><body><h1>Welcome!</h1><p>You’ve found our site!</p></body></html>

debugRender(doc)
// <html>
//   <body>
//     <h1>
//       Welcome!
//     </h1>
//     <p>
//       You’ve found our site!
//     </p>
//   </body>
// </html>

While this rendering format is not suitable for the browser (it can introduce additional, unwanted whitespace), it’s perfect for reading and snapshot testing.

HtmlSnapshotTesting

Speaking of snapshot testing, swift-html now comes with a helper module, HtmlSnapshotTesting!

A couple months ago we had our first official release of SnapshotTesting, a library that lets you snapshot test not only UIViews to images, but any value to any format. We’ve been snapshot testing the HTML of the Point-Free web site since day one, so we’re excited to make this kind of testing easier for everyone.

You can snapshot test swift-html’s Node type using the html strategy.

import Html
import HtmlSnapshotTesting
import SnapshotTesting
import XCTest

class MyWebPageTests: XCTestCase {
  func testMyWebPage() {
    let doc = html([
      body([
        h1(["Welcome!"]),
        p(["You’ve found our site!"])
        ])
      ])

    // Assert against an HTML reference on disk
    assertSnapshot(matching: doc, as: .html)
  }
}

Bug fixes and performance improvements

This release also contains a few bug fixes from the community and free rendering performance improvements thanks to a heavy dose of inout.


To give swift-html a try today, check out its GitHub page.


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