Regex expression to find all occurences of 'NSLocalizedString' in file contents

Question

Test cases:

// With text and comment
NSLocalizedString(@"Example Text", @"Example Comment");

// With text and no comment
NSLocalizedString(@"Example, text", nil) 

// With text and comment with paranthesis
NSLocalizedString(@"Example text", @"Example (with paranthesis) comment") 

// With property and no comment
NSLocalizedString(test, nil)

// With property and comment
NSLocalizedString(test, @"Example comment")

// Inline
NSLocalizedString(@"Error", nil) NSLocalizedString(@"Change settings", @"Option to change HTTP Post settings") NSLocalizedString(@"Cancel", nil)

What I'm looking for: one match per NSLocalizedString occurance, with two capture groups (key and comment). Key may have a value or be nil.

What I've tried: r'NSLocalizedString\((.*)\s*,\s*(.*)\)'

This works for most of the cases, except for the last one (Inline) because it matches at the last comma.

Regex101: https://regex101.com/r/4OJgU2/6

Answer 1

You may solve the problem using

r'(?s)NSLocalizedString\(\s*(@\"[^\"\\]*(?:\\.[^\"\\]*)*\"|\w+)\s*,\s*(@\"[^\"\\]*(?:\\.[^\"\\]*)*\"|\w+)\)'

and the replacement

r'NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], \1, \2)'

Details

• NSLocalizedString\( - NSLocalizedString( substring
• \s* - 0+ whitespaces
• (@\"[^\"\\]*(?:\\.[^\"\\]*)*\"|\w+) - Group 1:
  • @\"[^\"\\]*(?:\\.[^\"\\]*)*\" - @" followed with 0+ chars other than " and \ followed with 0+ repetitions of any escaped char followed with 0+ chars other than " and \ and then a " (it is the Obj-C string literal matching pattern)
  • | - or
  • \w+ - 1+ word chars
• \s*,\s* - , enclosed with 0+ whitespaces
• (@\"[^\"\\]*(?:\\.[^\"\\]*)*\"|\w+) - Group 2
• \) - a ) char.

See the Python demo:

import re
strs = ['NSLocalizedString(@"Example Text", @"Example Comment");', 'NSLocalizedString(@"Example, text", nil)', 'NSLocalizedString(@"Example text", @"Example (with paranthesis) comment")', 'NSLocalizedString(test, nil)', 'NSLocalizedString(test, @"Example comment")', 'NSLocalizedString(@"Error", nil) NSLocalizedString(@"Change settings", @"Option to change HTTP Post settings") NSLocalizedString(@"Cancel", nil)']
pat = re.compile(r'NSLocalizedString\(\s*(@\"[^\"\\]*(?:\\.[^\"\\]*)*\"|\w+)\s*,\s*(@\"[^\"\\]*(?:\\.[^\"\\]*)*\"|\w+)\)', re.DOTALL)
repl = r'NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], \1, \2)'
for s in strs:
    print('----------------------------------\n{}\nVVVVVVVVVVVVVVVVVVVV'.format(s))
    res = pat.sub(repl, s)
    print(res)

Output:

----------------------------------
NSLocalizedString(@"Example Text", @"Example Comment");
VVVVVVVVVVVVVVVVVVVV
NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], @"Example Text", @"Example Comment");
----------------------------------
NSLocalizedString(@"Example, text", nil)
VVVVVVVVVVVVVVVVVVVV
NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], @"Example, text", nil)
----------------------------------
NSLocalizedString(@"Example text", @"Example (with paranthesis) comment")
VVVVVVVVVVVVVVVVVVVV
NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], @"Example text", @"Example (with paranthesis) comment")
----------------------------------
NSLocalizedString(test, nil)
VVVVVVVVVVVVVVVVVVVV
NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], test, nil)
----------------------------------
NSLocalizedString(test, @"Example comment")
VVVVVVVVVVVVVVVVVVVV
NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], test, @"Example comment")
----------------------------------
NSLocalizedString(@"Error", nil) NSLocalizedString(@"Change settings", @"Option to change HTTP Post settings") NSLocalizedString(@"Cancel", nil)
VVVVVVVVVVVVVVVVVVVV
NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], @"Error", nil) NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], @"Change settings", @"Option to change HTTP Post settings") NSLocalizedStringWithDefaultValue(@"elementID", nil, [NSBundle mainBundle], @"Cancel", nil)