Fluentvalidation 6.4.1.0 支持我使用不正确的正则表达式

Question

In my case, i want to validate for url image, some url is valid but result is wrong. Eg: link image is "https://fuvitech.online/wpcontent/uploads/2021/02/bta16600brg.jpg" or "https://fuvitech.online/wp-content/uploads/2021/02/bta16-600brg.jpg" reponse "The image link is not in the correct format".

My code here:

RuleFor(product => product.Images)
            .Length(1, 3000).WithMessage(Labels.importProduct_ExceedDescription, p => ImportHelpers.GetColumnName(typeof(ProductEntity).GetProperty(nameof(p.Images))))
            .Matches(@"^(http:\/\/|https:\/\/){1}?[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?$").WithMessage(Labels.importProduct_UrlNotCorrect, p => ImportHelpers.GetColumnName(typeof(ProductEntity).GetProperty(nameof(p.Images))));

Please help me where the above regex is wrong. Thank you.

Answer 1

Try this:

NOTE the following regex pattern may trigger false positives and also may ignore valid image URLs, because it is very difficult to validate whether a given URL is valid.

^https?:\/\/(?:(?:[A-Za-z0-9]+(?:-[A-Za-z0-9]+)+|[A-Za-z0-9]{2,})\.)+[A-Za-z]{2,}(?::\d+)?\/(?:(?:[A-Za-z0-9]+(?:(?:-[A-Za-z0-9]+)+)?\/)+|)[\w-]+\.(?:jpg|jpeg|png)$

Explanation

• ^ the start of a line/string.

• https?:\/\/ match http with an optional letter s , followed by :// .

• (?:(?:[A-Za-z0-9]+(?:-[A-Za-z0-9]+)+|[A-Za-z0-9]{2,})\.)+ This will match things like foo-foo.bar-bar. , foo.bar-bar. and foo.

• [A-Za-z]{2,} this will match the TLD part, eg, com , org , this part with the previous part will match things like foo-foo.bar-bar.com , foo.bar-bar.com or foo.com .

• (?::\d+)? optional group of (a colon : followed by one or more digits) for port part.

• \/(?:(?:[A-Za-z0-9]+(?:(?:-[A-Za-z0-9]+)+)?\/)+|) this check for two things, the first one is /uploads/public-images/ , /uploads/images/ , the second one is a single / .

• [\w-]+ this part for the file name, eg, bta16-600brg .

• \.(?:jpg|jpeg|png) you can add here multiple extensions, you can allow uppercase letters by using for example, [Jj][Pp][Gg] for jpg .

• $ the end of the line/string.

See regex demo

Answer 2

Thanks @SaSkY answer my question. I found my mistake. This source [ .[az]{2,5}] only allows domain extensions from 2-5 characters. Example [.com] is valid. But in my case [.online] was not valid. I changed to [ .[az]{1,10}].