How do I add a multi-line parameter to the RegularExpression attribute?
I use:
[RegularExpression(@"^(""|\[)?[a-zA-Z0-9']{1,125}(""|\])?$")]
to make sure each line of the multiline text box is matched correctly. However, I cannot figure out how to add the global flag and multline flag options. Is this not possible with MVC? What other options do I have?
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Doesn't seem to RegularExpressionAttribute
support run parameters, so here it allows (compile checked but not checked):
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter,
AllowMultiple = false)]
public class RegExAttribute : ValidationAttribute
{
public string Pattern { get; set; }
public RegexOptions Options { get; set; }
public RegExAttribute(string pattern) : this(pattern, RegexOptions.None) { }
public RegExAttribute(string pattern, RegexOptions options)
{
Pattern = pattern;
Options = options;
}
public override bool IsValid(object value)
{
return Regex.IsMatch(value.ToString(), Pattern, Options);
}
}
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You can add an inline option to enable MultiLine without adding the RegexOptions overload to the attribute. This will also ensure that the expression will work in Javascript as well.
[RegularExpression(@"(?m)^(""|\[)?[a-zA-Z0-9']{1,125}(""|\])?$")]
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This is how you could do it with Regex, basically without relying on a multi-line flag or attribute, instead you explicitly define a regex to allow newlines, but the same pattern should follow
[RegularExpression(@"^(""|\[)?[a-zA-Z0-9']{1,125}(""|\])?(?:\r?\n(""|\[)?[a-zA-Z0-9']{1,125}(""|\])?)*$")]
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