iOS: how to change colour/font of some characters of a string

Question

in my app i have to change the font of a part of string which comes from JSON response

> "<span class=\"drop_data_user\">Andrew James</span> liked your comment
> \"hiiiiiiiiiiiiiii\" that you posted."

to convert it in attributed string i am using the following code

NSAttributedString *attr = [[NSAttributedString alloc] initWithData:[NotificationTxt dataUsingEncoding:NSUTF8StringEncoding]
                                                                options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
                                                                          NSCharacterEncodingDocumentAttribute:@(NSUTF8StringEncoding)}
                                                     documentAttributes:nil
                                                                  error:nil];

I want to change the font colour of the sender

How do you define that "Andrew James" is the sender? Will it always be between that particular span html tag? — Larme, Feb 05 '18 at 09:03
Since that tag won't be "interpreted" but committed (tested on Playground), I'd suggest to find it with `rangeOfString:`, a `NSRegularExpression` (if it's always the same one), `NSScanner`, etc. and add (or replace it) yourself a HTML tag defining a color for it. — Larme, Feb 05 '18 at 09:12
this might be helpful https://stackoverflow.com/questions/22090597/how-to-add-css-of-an-html-to-nsattributedstring — heximal, Feb 05 '18 at 09:41

score 1 · Answer 1 · edited Sep 15 '20 at 13:39

Also, you can use it as follows.

NSString *dateString = [NSString stringWithFormat:@"%@%@", @"Teslimat: ", selectedReservationModel.DateLabel];
        NSMutableAttributedString *attrS = [[NSMutableAttributedString alloc] initWithString: dateString];
        [attrS addAttribute:NSFontAttributeName value:[GenericUtility getOpenSansBoldFontSize:12] range:NSMakeRange(0, 8)];
        [attrS addAttribute:NSFontAttributeName value:[GenericUtility getOpenSansRegularFontSize:12] range:NSMakeRange(9, selectedReservationModel.DateLabel.length)];
        lblDeliveryDate.attributedText = attrS;

score 0 · Answer 2 · answered Feb 05 '18 at 09:16

I believe the easiest way to fulfil your task is to use CSS inlined in the text, then parsing HTML as you do will change the color too (I'm using Swift syntax, but I believe you can easily convert it to ObjC):

let text = "<span class=\"drop_data_user\">Andrew James</span> liked your comment \"hiiiiiiiiiiiiiii\" that you posted."
let colouredAuthorText = "\(text)<style>.drop_data_user { color: #FEB600; }</style>"

Then just parse colouredAuthorText (which is created by appending style to the original text) instead of the original, and you should be good to go.

score 0 · Accepted Answer · answered Feb 05 '18 at 09:18

0

NSMutableAttributedString *attrS = [[NSMutableAttributedString alloc] initWithString:@"My String"];
[attrS addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0, 2)];
[attrS addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(3, 6)];

self.myLabel.attributedText = attrS;

For fonts use

[attrS addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:20] range:NSMakeRange(0, 3)];

answered Feb 05 '18 at 09:18

Ryan Heitner

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how can i use this code if range is dynamic as in my ques string comes from json response – Abhinandan Pratap Feb 05 '18 at 09:23
Calculate where in the string your Sender is and adjust the range accordingly. I don't have enough information to show you. – Ryan Heitner Feb 05 '18 at 09:28

iOS: how to change colour/font of some characters of a string

3 Answers3