Problem
I’m trying to make an html-formatted sample of text display well in a UITableViewCell on an iPhone.
So far, I’ve got:
NSError* error;
NSString* source = @"<strong>Nice</strong> try, Phil";
NSMutableAttributedString* str = [[NSMutableAttributedString alloc] initWithData:[source dataUsingEncoding:NSUTF8StringEncoding]
options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
NSCharacterEncodingDocumentAttribute: [NSNumber numberWithInt:NSUTF8StringEncoding]}
documentAttributes:nil error:&error];
This is the kind of thing that works. I get some text with the word ‘Nice’ bolded! However, it also selects Times Roman as the font! This isn’t the typeface I’m looking for. I believe I need to set something in documentAttributes, but I can’t seem to find any examples.
Asked by phil
Solution #1
Based on Javier Querol’s response, I created a Swift 2 version.
extension UILabel {
func setHTMLFromString(text: String) {
let modifiedFont = NSString(format:"<span style=\"font-family: \(self.font!.fontName); font-size: \(self.font!.pointSize)\">%@</span>", text) as String
let attrStr = try! NSAttributedString(
data: modifiedFont.dataUsingEncoding(NSUnicodeStringEncoding, allowLossyConversion: true)!,
options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: NSUTF8StringEncoding],
documentAttributes: nil)
self.attributedText = attrStr
}
}
iOS 9+ and Swift 3.0
extension UILabel {
func setHTMLFromString(htmlText: String) {
let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: \(self.font!.pointSize)\">%@</span>", htmlText)
let attrStr = try! NSAttributedString(
data: modifiedFont.data(using: .unicode, allowLossyConversion: true)!,
options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue],
documentAttributes: nil)
self.attributedText = attrStr
}
}
iOS 11+ and Swift 5
extension UILabel {
func setHTMLFromString(htmlText: String) {
let modifiedFont = String(format:"<span style=\"font-family: '-apple-system', 'HelveticaNeue'; font-size: \(self.font!.pointSize)\">%@</span>", htmlText)
let attrStr = try! NSAttributedString(
data: modifiedFont.data(using: .unicode, allowLossyConversion: true)!,
options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding:String.Encoding.utf8.rawValue],
documentAttributes: nil)
self.attributedText = attrStr
}
}
Answered by Víctor Albertos
Solution #2
#import "UILabel+HTML.h"
@implementation UILabel (HTML)
- (void)jaq_setHTMLFromString:(NSString *)string {
string = [string stringByAppendingString:[NSString stringWithFormat:@"<style>body{font-family: '%@'; font-size:%fpx;}</style>",
self.font.fontName,
self.font.pointSize]];
self.attributedText = [[NSAttributedString alloc] initWithData:[string dataUsingEncoding:NSUnicodeStringEncoding]
options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
NSCharacterEncodingDocumentAttribute: @(NSUTF8StringEncoding)}
documentAttributes:nil
error:nil];
}
@end
You won’t have to specify the font you want because it will use the label font and size instead.
Answered by Javier Querol
Solution #3
I was able to find a solution to this problem:
Before your HTML response string is parsed, you can change the font.
NSString *aux = [NSString stringWithFormat:@"<span style=\"font-family: YOUR_FONT_NAME; font-size: SIZE\">%@</span>", htmlResponse];
Example:
NSString *aux = [NSString stringWithFormat:@"<span style=\"font-family: HelveticaNeue-Thin; font-size: 17\">%@</span>", [response objectForKey:@"content"]];
Swift version:
let aux = "<span style=\"font-family: YOUR_FONT_NAME; font-size: SIZE\">\(htmlResponse)</span>"
Answered by Teodor Ciuraru
Solution #4
Figured it out. Bit of a bear, and maybe not the best answer.
This code will go over all of the font variations. I’m aware that the fonts are “Times New Roman” and “Times New Roman BoldMT.” But regardless, this will find the bold fonts and let me reset them. I can also reset the size while I’m at it.
I honestly hope/believe there is a way to do this at parse time, but if there is, I can’t find it.
NSRange range = (NSRange){0,[str length]};
[str enumerateAttribute:NSFontAttributeName inRange:range options:NSAttributedStringEnumerationLongestEffectiveRangeNotRequired usingBlock:^(id value, NSRange range, BOOL *stop) {
UIFont* currentFont = value;
UIFont *replacementFont = nil;
if ([currentFont.fontName rangeOfString:@"bold" options:NSCaseInsensitiveSearch].location != NSNotFound) {
replacementFont = [UIFont fontWithName:@"HelveticaNeue-CondensedBold" size:25.0f];
} else {
replacementFont = [UIFont fontWithName:@"HelveticaNeue-Thin" size:25.0f];
}
[str addAttribute:NSFontAttributeName value:replacementFont range:range];
}];
Answered by phil
Solution #5
While enumerating font features, a more generic technique is to construct a font with the same traits (bold, italic, etc.):
extension NSMutableAttributedString {
/// Replaces the base font (typically Times) with the given font, while preserving traits like bold and italic
func setBaseFont(baseFont: UIFont, preserveFontSizes: Bool = false) {
let baseDescriptor = baseFont.fontDescriptor
let wholeRange = NSRange(location: 0, length: length)
beginEditing()
enumerateAttribute(.font, in: wholeRange, options: []) { object, range, _ in
guard let font = object as? UIFont else { return }
// Instantiate a font with our base font's family, but with the current range's traits
let traits = font.fontDescriptor.symbolicTraits
guard let descriptor = baseDescriptor.withSymbolicTraits(traits) else { return }
let newSize = preserveFontSizes ? descriptor.pointSize : baseDescriptor.pointSize
let newFont = UIFont(descriptor: descriptor, size: newSize)
self.removeAttribute(.font, range: range)
self.addAttribute(.font, value: newFont, range: range)
}
endEditing()
}
}
Answered by markiv
Post is based on https://stackoverflow.com/questions/19921972/parsing-html-into-nsattributedtext-how-to-set-font