I'm looking for a regular expression that which will match a string ##test## in a text. The string can be surround by any word or nonword character, or white-space, or newline - so everything can be one the left and on the right of the string, no matter.
I need to use it in a asp.net RegularExpressionValidator control for ValidationExpression.
Thanks in advance for help !
Regards.
<asp:RegularExpressionValidator ID="RegularExpressionValidator9" runat="server" ControlToValidate="TextBox1"
Display="Dynamic" ValidationGroup="Mail" ErrorMessage="Insert !"
ValidationExpression="(\w|\s|\n)##test##(\w|\s|\n)" >*</asp:RegularExpressionValidator>
<asp:Button ID="Button1" runat="server" Text="Button"
ValidationGroup="Mail" Onclick="Button1_Click" />
This should do it:
ValidationExpression="[\s\S]*##test##[\s\S]*"
I can see three problem with your regex, all having to do the (\w|\s|\n) portion:
It will match exactly one character. You need it to match zero or more characters; adding the * quantifier does that.
It's needlessly redundant and gratuitously inefficient. [\w\s] matches the same things: a word character (\w) or a whitespace character (\s, which already includes \n). And whenever you have a choice between using and alternation ((a|b|c)) or a character class ([abc]), the character class should always be the first tool you reach for. It may look like a trivial choice, but it can have a huge impact on performance.
It leaves out a lot of characters, most notably punctuation characters like !, +, ., etc..
If you're wondering why I used [\s\S]* and not .*, it's because the validation can be performed either in the browser or the server. In JavaScript regexes, as in most other flavors, the . metacharacter doesn't match newlines. Most of the others also support a "single-line" or "dot-matches-all" mode, but not JavaScript.
Of course, you could just force it to run on the server only, but you might as well get into habit of dumbing down your regexes to JavaScript's level when you can. :-/
Something like this?
.*(##test##).*
Related
Here I have a MaskedEditExtender, with a validator using a regex.
It validates phone numbers with 8 or 9 digits:
<asp:TextBox Style="width: 135px" ID="txtTelefone" runat="server"></asp:TextBox>
<ajaxToolkit:MaskedEditExtender
ID="MaskedEditExtender_Telefone"
TargetControlID="txtTelefone"
runat="server"
Mask="\(99\)9999NN9999"
OnInvalidCssClass="txt-TextBox-Error"
ValidateRequestMode="Enabled"
ErrorTooltipEnabled="True"
Filtered="-"
PromptCharacter=" "
ClearMaskOnLostFocus="false"/>
<ajaxToolkit:MaskedEditValidator
ID="MaskedEditValidator_Telefone"
runat="server"
ControlExtender="MaskedEditExtender_Telefone"
ControlToValidate="txtTelefone"
ValidationExpression="^\(\d\d\)\d\d\d\d+-\d\d\d\d$"
Display="Dynamic"></ajaxToolkit:MaskedEditValidator>
The issue is: as you can see in the regex, the user can put 4 or 5 digits between the ')' and the '-'.
But the "Mask" field doesn't allow it.
I need the MaskedEditExtender to stop crying when I don't type all the characters, because they're not necessary. All I need to validate my field is the regex.
The MaskedEditExtender is there only to give a mask that allows me to type only numbers and have a (99) in the beggining. It does not need to validate anything.
Well, seems like there's no such functionality in MaskedEditExtender that allows you to put less than the characters in the mask, so I did a small workaround:
I've put autocomplete in the mask, adapted the regex to accept an empty space in the end of the string and trimmed it everytime I wanted to use the TextBox's value.
In MaskedEditValidator:ValidationExpression="^\(\d{2}\)\d{4,5}-\d{4} *$"
In MaskedEditExtender:AutoComplete="true" AutoCompleteValue=""
In CodeBehind: txtTelefone.Text.Trim();
With this, all unfilled characters will be replaced as space in the end of the string, the regex will take care of the validation, and the Trim() will remove the spaces. Thus allowing you to make the Mask's length optional.
Set ClearMaskOnLostFocus="true" on MaskedEditExtender.
So how do I add that it should not have empty field in this same line including my other validation for alphanumeric reg ex.
^[A-Za-z0-9 _]*[A-Za-z0-9][A-Za-z0-9 _]*$
I tried this and didn't work
^[A-Za-z0-9 _]*[A-Za-z0-9][A-Za-z0-9 _]*$ | /\S/
This is for validation controls
<asp:RegularExpressionValidator id="userLocationValidation" runat="server"
ControlToValidate="userLocation"
ValidationExpression="/\S/"
ErrorMessage="Only use letters from the english alphabet a-z">
</asp:RegularExpressionValidator>
Use:
^[A-Za-z0-9 _]+[A-Za-z0-9][A-Za-z0-9 _]*$
The '+' says one or more, so empty fields will fail.
^[a-zA-Z0-9 _]+$
+ means at least one
if you mean at least one not white-space character something like
^[a-zA-Z0-9 _]*[a-zA-Z0-9_]+[a-zA-Z0-9 _]*$
I'm trying to limit the punctuation that a user can enter into a text box and am using this regex:
^[\w ,-–\[\\\^\$\.\|\?\*\+\(\)\{\}/!##&\`\.'\n\r\f\t""’]*$
Why do > and < produce a match? They are not included in the regex.
NOTE: this is being used in a asp.net regular expression validator.
Edit: here's the asp.net source:
<input runat="server" type="text" id="txt_FName" class="textbox" maxlength="60" />
<asp:RegularExpressionValidator ID="rfvRegexFName" runat="server" ControlToValidate="txt_FName" ErrorMessage="<%$ Resources:Subscribe, inputValidationError %>" />
In the code behind I add the expression:
rfvRegexFName.ValidationExpression = #"^[\w ,-–\[\\\^\$\.\|\?\*\+\(\)\{\}/!##&\`\.'\n\r\f\t""’]*$";
Why do > and < produce a match?
Probably because the - (hyphen) in ,-– matches the character range [, to –]. Either escape the hyphen: ,\-– or place the hyphen at the very start or end of the class which causes it to match the literal - instead.
Also note that you need not escape the $, ., |, ?, *, +, (, ), { and } inside a character class
Edit: After seeing the other answers, it looks like there might have been a few things going on here. The main problem was the unescaped dash, though. For future reference of anyone reading this Q/A thread, see Bart Kiers' answer.
You don't want to escape the period. When it's inside the brackets, it matches a regular period by default, not any character like it does normally. I'm not positive, but that might be making it act as a special character again, therefore matching anything.
Try this:
^[\w ,-–\[\\\^\$.\|\?\*\+\(\)\{\}/!##&\`'\n\r\f\t""’]*$
Try changing the last * to a +. You're matching zero or more instances, which always guarantees a match.
Edit to add: Are all of those characters regular ASCII? It looks like you might be using an em-dash or something, which might be related to your problem.
I'm trying to validate an ASP TextBox that can only have 1-2 digits (not zero) using the following regex:
^[1-9]{1,2}
This regex doesn't validate if the field is empty (assumed it would due to the 1-2 part)
Also tried ^[1-9+]{1,2} to no avail.
These are my controls:
<asp:TextBox ID="txtInHour"
MaxLength="2"
runat="server"
Text='<%# Bind("InHour") %>'
Width="80"/>
<asp:RegularExpressionValidator ID="rvInHour"
ControlToValidate="txtInHour"
Display="None"
ValidationExpression="^[1-9]{0,2}$"
runat="server"
ErrorMessage="InHour is incorrectly formatted." />
The first thing I notice is that you don't allow zeros in your pattern. So 10 or 20 is not valid? The second thing is that you start with "starts with" AKA "^" but there's no "ends with" AKA "$"
So.. try this:
^[1-9][0-9]?$
In human readable:
starts with 1-9, followed by an optional digit from 0-9, end of string.
On the other hand I don't know what you've meant with ("no zeros") - no zeros at all?!
I found out that for some reason RegularExpressionValidators don't work when there's no input to match against (blank fields) so I had to use a seperate RequiredFieldValidator. Thanks for your input everyone!
You can use this regex :
^([1-9]|[1-9][0-9])$
I'm using the ASP Validation control a wanted to test that multiline textbox content was between 2 and 40 characters. Any character can be provided, including the new line character. What would be the expression? What I have below fails.
<asp:RegularExpressionValidator ID="RegularExpressionValidator"
runat="server"
ValidationExpression="^[.]{2,40}$"
ControlToValidate="CommentsTextBox"
ErrorMessage="The Comment field must be between 2 and 40 characters"
Display="Dynamic">*</asp:RegularExpressionValidator>
When you put the dot inside square brackets, it loses its special meaning and just matches a literal dot. The easiest way to match any character in an ASP RegularExpressionValidator is like this:
^[\s\S]{2,40}$
[\s\S] is the standard JavaScript idiom for matching anything including newlines (because JS doesn't support DOTALL or s-mode, which allows the dot to match newlines). It works the same in .NET, so you don't have to worry about whether the dot matches newlines, or whether the regex will be applied on the server or the client.
You're treating the period as a literal inside the brackets. You just want:
^(.|\n){2,40}$