Increase or Decrease an Integer Within a NSString

Question

My app is a simple blog app. I parse an XML, and build custom HTML code from the parsed parts, and load that HTML into a webview. Not everyone has the same quality of vision, so I am trying to add simple buttonsto add or decrease the font size. Currently, the HTML may look like:

font size=5 The Title.../font font size = 3 The body of text.../font

What I would like to do is take whatever number is listed, and increase or decrease by 1.

Any suggestions on how I can take just those 2 numbers (don't want to increase other numbers that may be in body of article) and increase or decrease incrementally?

Answer 1

I'd recommend stuffing the HTML you parsed out of the XML into a "NSMutableString" object and then hunt through the mutable string object looking for the ranges of all substrings that match the pattern "font size=".

Once you find those ranges, you should be able to get the font sizes and then put them into a "NSInteger" via something like [NSString integerValue] which you can then increment and put back into the mutable string object. Obviously there's some extra detail I'm not thinking too hard about, like how to replace a "9" in the mutable string with a "10" or to tell the difference between a font size of "10" and one that's "100". But at least this should be a good start for you.