✨ Add slugify filter

Author: oschrenk

Docs/Templating.md

@@ -34,6 +34,7 @@ This is mostly standard [Stencil](https://stencil.fuller.li/en/latest/) templati
 You have access to
 - an `events` array
 - a custom `format` filter for date/time formatting (see cheatsheet [here](https://www.advancedswift.com/date-formatter-cheatsheet-formulas-swift/))
+- a custom `slugify` filter to create a url friendly version of it
 
 It assumes:
 - that your calendar names are without spaces

LICENSING.md

@@ -12,3 +12,8 @@ This project uses parts of the Apache licensed [MeetingBar](https://github.com/l
 This project has copies/variations of the [regular expressions](https://github.com/leits/MeetingBar/blob/b4af1de5d0d490c2a69c29024843995211865977/MeetingBar/MeetingServices.swift#L264) to identify services.
 
 See their license [here](https://github.com/leits/MeetingBar/blob/master/LICENSE)
+## dirtyhenry/swift-blocks
+
+This project uses parts of the MIT licensed [dirtyhenry/swift-blocks](https://github.com/dirtyhenry/swift-blocks) project.
+
+In particular the method to slugify a string, see [here](about)

Sources/IO/String.swift

@@ -0,0 +1,50 @@
+import Foundation
+
+// From
+// https://github.com/dirtyhenry/swift-blocks/blob/4e6b2fb079edb0ab0951a8fce061ee308c9d3503/Sources/Blocks/Extensions/StringProtocol.swift
+
+public extension StringProtocol {
+  /// Converts the string into a URL-friendly slug.
+  ///
+  /// This method transforms the string to lowercase, removes accents and combining marks, replaces spaces and
+  /// non-alphanumeric characters with hyphens, and trims leading and trailing hyphens.
+  ///
+  /// - Returns: A URL-friendly slug representation of the string.
+  ///
+  /// # Usage Example #
+  /// ```
+  /// let exampleString = "Hello, World! This is an example string with accents: é, è, ê, ñ."
+  /// let slugifiedString = exampleString.slugify()
+  /// print(slugifiedString)  // Output: "hello-world-this-is-an-example-string-with-accents-e-e-e-n"
+  /// ```
+  func slugify() -> String {
+    var slug = lowercased()
+
+    // Remove accents and combining marks
+    slug = slug.applyingTransform(.toLatin, reverse: false) ?? slug
+    slug = slug.applyingTransform(.stripDiacritics, reverse: false) ?? slug
+    slug = slug.applyingTransform(.stripCombiningMarks, reverse: false) ?? slug
+
+    // Replace spaces and non-alphanumeric characters with hyphens
+    slug = slug.replacingOccurrences(
+      of: "[\\+]+", with: "+plus+", options: .regularExpression
+    )
+    slug = slug.replacingOccurrences(
+      of: "[^a-z0-9]+", with: "-", options: .regularExpression
+    )
+
+    // Trim hyphens from the start and end
+    slug = slug.trimmingCharacters(in: CharacterSet(charactersIn: "-"))
+
+    if !isEmpty, slug.isEmpty {
+      if let extendedSelf = applyingTransform(.toUnicodeName, reverse: false)?
+        .replacingOccurrences(of: "\\N", with: ""), self != extendedSelf
+      // swiftlint:disable:next opening_brace
+      {
+        return extendedSelf.slugify()
+      }
+    }
+
+    return slug
+  }
+}

Sources/IO/Template.swift

@@ -34,6 +34,16 @@ class Template {
       return value
     }
 
+    // extension `<String>|slugify`
+    // transforms a string into a slug
+    ext.registerFilter("slugify") { (value: Any?, _: [Any?]) in
+      if let value = value as? String {
+        return value.slugify()
+      }
+
+      return value
+    }
+
     let context = ["events": events]
     let environment = Environment(
       loader: DictionaryLoader(templates: ["default": template]),