HTML to attributed string to HTML increase font size for random text

问题

This is my HTML sample string.

"<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01//EN\" \"http://www.w3.org/TR/html4/strict.dtd\"><html><head><meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"><meta http-equiv=\"Content-Style-Type\" content=\"text/css\"><title></title><meta name=\"Generator\" content=\"Cocoa HTML Writer\"><style type=\"text/css\">p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; line-height: 40.0px; font: 33.2px '.SF UI Text'; color: #000000; -webkit-text-stroke: #000000}span.s1 {font-family: '.SFUIText'; font-weight: normal; font-style: normal; font-size: 33.19pt; font-kerning: none}</style></head><body><p class=\"p1\"><span class=\"s1\">123</span></p></body></html>"

Here are two functions to converting from HTML to attribute string to HTML for dealing server size too.

Attribute string to HTML:

func attributeToHTML(_ attr: NSAttributedString) -> String {

    var resultHtmlText = ""
    do {

        let r = NSRange(location: 0, length: (attr.length))
        let att = [NSAttributedString.DocumentAttributeKey.documentType: NSAttributedString.DocumentType.html]
        let d = try attr.data(from: r, documentAttributes: att)

        if let h = String(data: d, encoding: .utf8) {
            resultHtmlText = h
        }
    }
    catch {
        print("utterly failed to convert to html!!! \n>\(String(describing: attr))<\n")
    }
    return resultHtmlText
}

HTML to Attributed string:

func htmlToAttribute(_ string: String) -> NSAttributedString {
    let htmlString = string
    var result = NSAttributedString()
    do {
        let options = [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html]
        let str = try NSAttributedString(data: htmlString.data(using: String.Encoding.unicode, allowLossyConversion: true)!, options: options, documentAttributes: nil)
        result = attributedString
    } catch {
        print(error)
    }

    return result
}

When I convert HTML string to attributed string it increases the font size, and working perfect with attributed string to HTML conversion.

By enumerating objects I can edit font size too, but its dynamic content any type of HTML string get in response. So this is not solutions.

Please suggest the way how to deal with HTML content in UITextview for editing and storing in server.

来源：https://stackoverflow.com/questions/51560409/html-to-attributed-string-to-html-increase-font-size-for-random-text

标签

html

ios

swift

nsattributedstring