Regex - Validate Url

  • Thread starter Thread starter shapper
  • Start date Start date
S

shapper

Hello,

I need to validate an url in my C# code.
Does anyone knows a reliable Regex to validate a Url?

Thanks,
Miguel
 
And be careful, since the most of the examples floating around on the
web only show how to validate a subset of valid URLs, which may or may
not be acceptable depending on your needs.
Click to expand...

I am using the following:
Boolean valid = Regex.IsMatch(context.PropertyValue, @"((?<=\()
[A-Za-z][A-Za-z0-9\+\.\-]*:([A-Za-z0-9\.\-_~:/\?#\[\]@!\$&'\(\)\*\
+,;=]|%[A-Fa-f0-9]{2})+(?=\)))|([A-Za-z][A-Za-z0-9\+\.\-]*:([A-Za-
z0-9\.\-_~:/\?#\[\]@!\$&'\(\)\*\+,;=]|%[A-Fa-f0-9]{2})+)");

Based on the following Regex:
http://blog.dieweltistgarnichtso.net/constructing-a-regular-expression-that-matches-uris

Not sure if it is the best one but it seems ok.

Basically in my case I am adding Slides (Images) to site in a CMS.
Each image can have a link to some site.
I want to be sure that the url inserted has a valid format.

Thanks,
Miguel
 
* shapper wrote, On 10-9-2009 17:15:
And be careful, since the most of the examples floating around on the
web only show how to validate a subset of valid URLs, which may or may
not be acceptable depending on your needs.
Click to expand...

I am using the following:
Boolean valid = Regex.IsMatch(context.PropertyValue, @"((?<=\()
[A-Za-z][A-Za-z0-9\+\.\-]*:([A-Za-z0-9\.\-_~:/\?#\[\]@!\$&'\(\)\*\
+,;=]|%[A-Fa-f0-9]{2})+(?=\)))|([A-Za-z][A-Za-z0-9\+\.\-]*:([A-Za-
z0-9\.\-_~:/\?#\[\]@!\$&'\(\)\*\+,;=]|%[A-Fa-f0-9]{2})+)");

Based on the following Regex:
http://blog.dieweltistgarnichtso.net/constructing-a-regular-expression-that-matches-uris

Not sure if it is the best one but it seems ok.

Basically in my case I am adding Slides (Images) to site in a CMS.
Each image can have a link to some site.
I want to be sure that the url inserted has a valid format.

Thanks,
Miguel
Click to expand...

If you want to make sure you can open the image and that the url
actually exists, the best way is to use the URI class and actually try
to open the resource using WebClient.

The definition of a URL/URI is so broad and can contain so many
protocols and subsequent URI scheme's that a regex probably only works
on the most standard cases.
 
* shapper wrote, On 10-9-2009 17:15:


I am using the following:
       Boolean valid = Regex.IsMatch(context.PropertyValue, @"((?<=\()
[A-Za-z][A-Za-z0-9\+\.\-]*:([A-Za-z0-9\.\-_~:/\?#\[\]@!\$&'\(\)\*\
+,;=]|%[A-Fa-f0-9]{2})+(?=\)))|([A-Za-z][A-Za-z0-9\+\.\-]*:([A-Za-
z0-9\.\-_~:/\?#\[\]@!\$&'\(\)\*\+,;=]|%[A-Fa-f0-9]{2})+)");
Click to expand...
Based on the following Regex:
http://blog.dieweltistgarnichtso.net/constructing-a-regular-expressio...
Click to expand...
Not sure if it is the best one but it seems ok.
Click to expand...
Basically in my case I am adding Slides (Images) to site in a CMS.
Each image can have a link to some site.
I want to be sure that the url inserted has a valid format.
Click to expand...
Thanks,
Miguel
Click to expand...

If you want to make sure you can open the image and that the url
actually exists, the best way is to use the URI class and actually try
to open the resource using WebClient.

The definition of a URL/URI is so broad and can contain so many
protocols and subsequent URI scheme's that a regex probably only works
on the most standard cases.
Click to expand...

No no ... The url I am mentioned is something like http://www.google.com
or http://www.thiswebsite.com/somesection, etc.
So when the user clicks that image it is redirected to the URL.
I am just testing if the user inserts a valid URL ... of course the
URL might not lead to nowhere by mistake but at least is a correct
url.
Just like a banner ...
 
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