iOS, Swift: Create a PDF file from an HTML string

iOSCreatePDF.swift

// Thanks to http://www.labs.saachitech.com/2012/10/23/pdf-generation-using-uiprintpagerenderer

import UIKit

// 1. Create a print formatter

let html = "<b>Hello <i>World!</i></b>"
let fmt = UIMarkupTextPrintFormatter(markupText: html)

// 2. Assign print formatter to UIPrintPageRenderer

let render = UIPrintPageRenderer()
render.addPrintFormatter(fmt, startingAtPageAtIndex: 0)

// 3. Assign paperRect and printableRect

let page = CGRect(x: 0, y: 0, width: 595.2, height: 841.8) // A4, 72 dpi
let printable = CGRectInset(page, 0, 0)

render.setValue(NSValue(CGRect: page), forKey: "paperRect")
render.setValue(NSValue(CGRect: printable), forKey: "printableRect")

// 4. Create PDF context and draw

let pdfData = NSMutableData()
UIGraphicsBeginPDFContextToData(pdfData, CGRectZero, nil)

for i in 1...render.numberOfPages() {

    UIGraphicsBeginPDFPage();
    let bounds = UIGraphicsGetPDFContextBounds()
    render.drawPageAtIndex(i - 1, inRect: bounds)
}

UIGraphicsEndPDFContext();

// 5. Save PDF file

let path = "\(NSTemporaryDirectory())file.pdf"
pdfData.writeToFile(path, atomically: true)
print("open \(path)") // command to open the generated file