objective c - HTML to NSAttributedString - objective-c

Question

I have written a function that converts HTML text to NSAttributedString. It is working fine. However, I have noticed that some tags when nested inside another tag, their fonts get overwritten.
Here's my code.
+(NSMutableAttributedString*) replaceHTMLTags : (NSString*) text : (NSString*) fontName : (CGFloat) fontSize
{
UIFont* font = [UIFont fontWithName:fontName size:fontSize];
NSMutableParagraphStyle* paragraphStyle = [[NSMutableParagraphStyle alloc]init];
paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
paragraphStyle.alignment = NSTextAlignmentJustified;
text = [text stringByReplacingOccurrencesOfString:#"<br>" withString:#"\n"];
NSMutableAttributedString* finalText = [[NSMutableAttributedString alloc]initWithString:text];
[finalText setAttributes:#{NSFontAttributeName:font} range:NSMakeRange(0, [finalText string].length)];
finalText = [self recurseFunc:finalText :#"" : font : paragraphStyle];
return finalText;
}
+(NSMutableAttributedString*) recurseFunc : (NSMutableAttributedString*) text : (NSString*) tag : (UIFont*) font : (NSMutableParagraphStyle*) paragraphStyle
{
NSMutableAttributedString* finalText = text;
NSRange newOpenTagRange;
//RECURSE IF THERE ARE MORE TAGS
while((newOpenTagRange = [[text string] rangeOfString:#"<[^>]+>" options:NSRegularExpressionSearch]).location != NSNotFound)
{
NSString* openTagName = [[text string] substringWithRange:newOpenTagRange];
NSString* closeTagName = [self getCloseTagName: openTagName];
NSRange newCloseTagRange = [[text string ]rangeOfString:closeTagName];
if(newCloseTagRange.location != NSNotFound)
{
NSString* textWithTags = [[text string] substringWithRange:NSMakeRange(newOpenTagRange.location, newCloseTagRange.location - newOpenTagRange.location + newCloseTagRange.length)];
NSString* newPlainText = [textWithTags stringByReplacingOccurrencesOfString:openTagName withString:#""];
newPlainText = [newPlainText stringByReplacingOccurrencesOfString:closeTagName withString:#""];
NSMutableAttributedString* newText = [[NSMutableAttributedString alloc]initWithString:newPlainText attributes:#{NSFontAttributeName:font, NSParagraphStyleAttributeName:paragraphStyle}];
newText = [self recurseFunc:newText :openTagName : font : paragraphStyle];
[finalText replaceCharactersInRange:NSMakeRange(newOpenTagRange.location, newCloseTagRange.location - newOpenTagRange.location + newCloseTagRange.length) withAttributedString:newText];
}
else
{
NSLog(#"Cannot find closing tag for tag %#", openTagName);
}
}
//FORMAT HTML TAGS
if([tag containsString:#"<p"])
{
[finalText.mutableString appendString:#"\n\n"];
}
else if ([tag isEqualToString:#"<i>"])
{
UIFont* italicFont = [UIFont fontWithName:#"Arial-ItalicMT" size:DEFAULT_FONT_SIZE];
[finalText addAttribute:NSFontAttributeName value:italicFont range:NSMakeRange(0, [finalText string].length)];
}
else if ([tag isEqualToString:#"<b>"])
{
UIFont* boldFont = [UIFont fontWithName:#"Arial-BoldMT" size:DEFAULT_FONT_SIZE];
[finalText addAttribute:NSFontAttributeName value:boldFont range:NSMakeRange(0, [finalText string].length)];
}
else if([tag isEqualToString:#"<ul>"])
{
NSMutableParagraphStyle* tempStyle = [[NSMutableParagraphStyle alloc]init];
tempStyle.headIndent = 30;
tempStyle.firstLineHeadIndent = 10;
tempStyle.lineBreakMode = NSLineBreakByWordWrapping;
tempStyle.alignment = NSTextAlignmentJustified;
NSString* temp = [[finalText string]stringByReplacingOccurrencesOfString:#"###" withString:#"•\t"];
temp = [NSString stringWithFormat:#"\n%#", temp];
[finalText setAttributedString:[[NSAttributedString alloc] initWithString:temp]];
[finalText addAttribute:NSParagraphStyleAttributeName value:tempStyle range:NSMakeRange(0, [finalText string].length)];
}
else if ([tag isEqualToString:#"<li>"])
{
NSMutableAttributedString* tempAS = [[NSMutableAttributedString alloc]initWithString:#"###$$$\n"];
NSRange r = [[tempAS string]rangeOfString:#"$$$"];
[tempAS replaceCharactersInRange:r withAttributedString:finalText];
[finalText setAttributedString:tempAS];
}
return finalText;
}
This does exactly what it is supposed to do, except for one specific case.
For instance, if I have a <b> or an <i> tag inside a <ul><li> tag, the <b> or <i> don't get rendered.

Answer 1

For converting HTML to NSAttributedString you can use the following code:
[[NSAttributedString alloc] initWithData:[htmlString dataUsingEncoding:NSUTF8StringEncoding]
options:#{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
NSCharacterEncodingDocumentAttribute: #(NSUTF8StringEncoding)}
documentAttributes:nil error:nil];