Separate error message for Minimum and Maximum string length - MVC4 Data annotation

Question

Would someone please share their implementation of having separate error messages for minimum and maximum string length using data annotations in MVC?

It seems StringLength only allows a single error message a MinLength/MaxLength do not generate unobtrusive validation markup as they are not IClientValidatable

Although this seems like a very common requirement I cannot find an implementation on the web.

[Regular expressions?](http://stackoverflow.com/a/8184202/609176) — David Spence, Feb 09 '13 at 23:10
Yup, javascript will execute the regular expressions client side — David Spence, Feb 10 '13 at 12:58
This should be done in 4.5 MinLength MaxLength attributes: https://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.maxlengthattribute(v=vs.110).aspx In my case I needed RegEx for some other error message and min max separatedly but I cannot upgrade version so I need to do custom validation. — Jozef Mera, Feb 17 '17 at 08:59

David Spence · Accepted Answer · 2013-08-08T10:16:12.597

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You can use the RegularExpression data annotation for the minimum check and use the StringLength attribute for the maximum check. Javascript will execute regular expressions client side so they are nice and unobtrusive! You can only use one RegularExpression attribute per property, otherwise you could do both maximum and minimum using regular expression.

Minimum of 5 characters

[RegularExpression(@"^.{5,}$", ErrorMessage = "Minimum 5 characters required")]

Maximum of 50 characters

[StringLength(50, ErrorMessage = "Maximum {2} characters exceeded")]

edited Aug 08 '13 at 10:16

answered Feb 10 '13 at 20:20

David Spence

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Hey I just tried this and I can't use 2 it says duplicate attribute! lol I still need a solution :( – parliament Feb 19 '13 at 09:39
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Ah. I knew they worked unobtrusively... What about using one of these for the minimum and `[StringLength(50, ErrorMessage = "Maximum {2} characters exceeded")]` for the max? – David Spence Feb 19 '13 at 10:52
Good idea :) I used StringLength(int.MaxValue, ErrorMessage = "Minimum") for min and regex for max. thanks again – parliament Feb 21 '13 at 06:06
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This fails when there is more than one line [RegularExpression(@"^[\s\S]{5,}$", ErrorMessage = "Minimum 5 characters required")] will make it work for multiple lines – girlcode Feb 05 '15 at 01:58
I personally don't think this is an appropriate answer, given that you may already be using a regex for something else (in my case a password field with a regex to check for specific characters). I think the right approach is probably to extend StringLength or create your own attribute. – Stevieboy84 Feb 26 '19 at 09:57

score 16 · Answer 2 · answered Aug 28 '13 at 20:58

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Although it is not separate messages, this is what I did:

[StringLength(30, ErrorMessage = "Must be between {2} and {1} characters long.", MinimumLength = 6)]

answered Aug 28 '13 at 20:58

Soenhay

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If you don't use [Required] and the string is empty, then MinimumLength is ignored. – CooncilWorker Mar 28 '16 at 15:35

score 0 · Answer 3 · answered Feb 03 '17 at 14:45

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[StringLength(800, ErrorMessage = "<img src='/images/icon-info.png' /><p>The {0} must be between {2} and {1} characters long.</p>", MinimumLength = 6)]

This will display an image and also min and max length.

answered Feb 03 '17 at 14:45

Stuart Smith

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Separate error message for Minimum and Maximum string length - MVC4 Data annotation

3 Answers3