Files
appchk-app/main/Common Classes/TinyMarkdown.swift

69 lines
2.2 KiB
Swift

import UIKit
struct TinyMarkdown {
/// Load markdown file and run through a (very) simple parser (see below).
/// - Parameters:
/// - filename: Will automatically append `.md` extension
/// - replacements: Replace a single occurrence of search string with an attributed replacement.
static func load(_ filename: String, replacements: [String : NSMutableAttributedString] = [:]) -> UITextView {
let url = Bundle.main.url(forResource: filename, withExtension: "md")!
let str = NSMutableAttributedString(withMarkdown: try! String(contentsOf: url))
for (key, val) in replacements {
guard let r = str.string.range(of: key) else {
QLog.Debug("WARN: markdown key '\(key)' does not exist in \(filename)")
continue
}
str.replaceCharacters(in: NSRange(r, in: str.string), with: val)
}
return QuickUI.text(attributed: str)
}
}
extension NSMutableAttributedString {
/// Supports only: `#h1`, `##h2`, `###h3`, `_italic_`, `__bold__`, `___boldItalic___`
convenience init(withMarkdown content: String) {
self.init()
let emph = try! NSRegularExpression(pattern: #"(?<=(^|\W))(_{1,3})(\S|\S.*?\S)\2"#, options: [])
beginEditing()
content.enumerateLines { (line, _) in
if line.starts(with: "#") {
var h = 0
for char in line {
if char == "#" { h += 1 }
else { break }
}
var line = line
line.removeFirst(h)
line = line.trimmingCharacters(in: CharacterSet(charactersIn: " "))
switch h {
case 1: self.h1(line + "\n")
case 2: self.h2(line + "\n")
default: self.h3(line + "\n")
}
} else {
let nsline = line as NSString
let range = NSRange(location: 0, length: nsline.length)
var i = 0
for x in emph.matches(in: line, options: [], range: range) {
let r = x.range
self.normal(nsline.substring(from: i, to: r.location))
i = r.upperBound
let before = nsline.substring(with: r)
let after = before.trimmingCharacters(in: CharacterSet(charactersIn: "_"))
switch (before.count - after.count) / 2 {
case 1: self.italic(after)
case 2: self.bold(after)
default: self.boldItalic(after)
}
}
if i < range.length {
self.normal(nsline.substring(from: i, to: range.length) + "\n")
} else {
self.normal("\n")
}
}
}
endEditing()
}
}