Validate user-entered RegEx in cocoa

Question

I have a predicate editor that allows the user to use "matches" for RegEx, thus they are entering a text string that is a RexEx used to search. If they enter something wrong, I get:

Can't open pattern U_REGEX_RULE_SYNTAX (string /Volumes/[path to certain file].mp4, pattern (*.abc.*)|(*.abd.*), case 1, canon 2)

How can I validate the string? If I don't and the user saves the file, it quits when trying to resolve this.

What does the code look like? – Wiktor Stribiżew Sep 07 '17 at 21:59 — Wiktor Stribiżew, Sep 07 '17 at 21:59
Do you use `NSRegularExpression` or `NSPredicate`? – Willeke Sep 07 '17 at 23:06 — Willeke, Sep 07 '17 at 23:06

score 0 · Answer 1 · answered Sep 08 '17 at 23:06

0

This seems to work:

@try
{
    NSPredicate* predicate = [[self predicateEditor] objectValue];
    [predicate evaluateWithObject:myObject];
}
@catch (NSException* exception)

    NSLog(@"Attempted to create invalid criteria, probably a bad RegEx");
    error = YES;
}

answered Sep 08 '17 at 23:06

Trygve

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Yes it does work. I could have answered your question yesterday if you had answered my question. – Willeke Sep 09 '17 at 10:51
How would I validate correct syntax of a NSRegularExpression? – Trygve Sep 09 '17 at 15:00
I don't know, I use `NSRuleEditor` and had the same problem. – Willeke Sep 10 '17 at 00:16

Validate user-entered RegEx in cocoa

1 Answers1