xcode - create an attributed string out of plain (Android formated) text in swift for iOS -

i reading strings out of localizable.strings contains have in strings.xml of android app

"testshort" = "a <b>short</b>\ntest another<b>bold text</b>"; 

the bold , and line feed 2 formatting attributes have in texts. trying develop method days without success:

func converttext(inputtext: string) -> nsattributedstring {     // here comes conversion representation helvetica 14pt , helvetica-bold 14pt including line feeds. } 

my final goal display text in uitextview's attributedtext.

being kinda new swift , ios without knowing objective-c found difficult string manipulations quite different , complex , examples in objective-c. makes harder api methods not available or different in swift in objective-c...

here tried far method body of lot of other posts here:

var test = inputtext.datausingencoding(nsunicodestringencoding, allowlossyconversion: true)! attrstr = nsattributedstring(         data: test,         options: [nsdocumenttypedocumentattribute: nshtmltextdocumenttype],         documentattributes: nil,         error: nil)! return attrstr 

the main issues here \n isn't converted , font small , different.

next tried manually bold part of text. seem work that:

var newtext = nsmutableattributedstring(string: inputtext) newtext.addattribute(nsfontattributename, value: uifont(name: "helvetica-bold", size: 14.0)!, range: nsrange(location:2,length:4)) 

now tried search attributes in text, deleting them , use addattribute kinda that

// start of bold text var range = newtext.rangeofstring("<b>")! // end of bold text var range2 = newtext.rangeofstring("</b>")!  // replacing attributes newtext = newtext.stringbyreplacingcharactersinrange(range, withstring: "") newtext = newtext.stringbyreplacingcharactersinrange(range2, withstring: "")  // creating range bold => error "'string.index' not convertible 'int'" // how such thing var boldrange = nsmakerange(range.startindex, range2.endindex -3)  // setting bold newtext.addattribute(nsfontattributename, value: uifont(name: "helvetica-bold", size: 14.0)!, range: boldrange) 

this whole range thing main issue @ moment quite different simple position in string.

this issue great example lack of (or hidden) documentation:

the addattribute wants nsrange, rangeofstring seems deliver generic range according error message - there no info it. search documentation button in xcode on rangeofstring() leads nsstring. searching in there rangeofstring()says returns nsrange. clicking on leads info of type alias _nsrange in turn has 2 nsuinteger properties named location , length. startindex , endindex property see in xcode? confusing...

would great if can give me snippets or hints i'm wrong here or method body i'm still hoping not difficult if know ios , swift well. i'm aiming ios 7.1 support if way easier ios 8 fine well.

regarding first method nsattributedstring:

• the \n character in html ordinary white space. line break have replace <br /> first.
• the font attributes can controlled html <span>, see parsing html nsattributedtext - how set font?.

this gives (now updated swift 2):

func converttext(inputtext: string) -> nsattributedstring {      var html = inputtext      // replace newline character html line break     while let range = html.rangeofstring("\n") {         html.replacerange(range, with: "<br />")     }      // embed in <span> font attributes:     html = "<span style=\"font-family: helvetica; font-size:14pt;\">" + html + "</span>"      let data = html.datausingencoding(nsunicodestringencoding, allowlossyconversion: true)!     let attrstr = try? nsattributedstring(         data: data,         options: [nsdocumenttypedocumentattribute: nshtmltextdocumenttype],         documentattributes: nil)     return attrstr! } 

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regarding second method:

there 2 different rangeofstring() methods, 1 (swift) string , 1 (foundation) nsstring. string method returns range<string.index> , nsstring method returns nsrange.

converting between these 2 possible complicated. reason in string each "extended grapheme cluster" counts 1 character, whereas in nsstring each utf-16 unit counted. extended grapheme cluster can 1 or more utf-16 unit ("😄" 2 utf-16 units, "🇩🇪" four).

the addattribute() method accepts nsrange. easiest method solve problem convert swift string nsstring , work nsrange only. method this:

func converttext(inputtext: string) -> nsattributedstring {      let attrstring = nsmutableattributedstring(string: inputtext)     let boldfont = uifont(name: "helvetica-bold", size: 14.0)!      var r1 = (attrstring.string nsstring).rangeofstring("<b>")     while r1.location != nsnotfound {         let r2 = (attrstring.string nsstring).rangeofstring("</b>")         if r2.location != nsnotfound  && r2.location > r1.location {             let r3 = nsmakerange(r1.location + r1.length, r2.location - r1.location - r1.length)             attrstring.addattribute(nsfontattributename, value: boldfont, range: r3)             attrstring.replacecharactersinrange(r2, withstring: "")             attrstring.replacecharactersinrange(r1, withstring: "")         } else {             break         }         r1 = (attrstring.string nsstring).rangeofstring("<b>")     }      return attrstring }