Question

I have to make dynamic replacement into HTML files on iOS App.

It s about localisation.

in the HTML files, I ve got things like : LANG(183) which must be turned into “a localized string”

I was looking at stringByreplacingMatchesInString but cant find any version that accept a callback function? do I miss something ?

Answer 1

You could use a block-based matching method of NSRegularExpression:

NSMutableString *newString = [htmlString mutableCopy];
[regex enumerateMatchesInString:htmlString
                        options:0
                          range:NSMakeRange(0, [htmlString length])
                     usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
                         // [result range] is the matching range.
                         // Do something with newString.
                     }
];

(As far as I know) you must not modify htmlString inside the block. Therefore you have to create a mutable copy first which you can modify in the block.

Of course, you have to keep track of changes in the length of newString, because the matching range will always refer to htmlString.