A contact form on a website rejected an email address I've been using for years. I assumed it was because my TLD is .Email, so I put the real address in the body and put Wrong.Address#Nowhere.com in the field. Still claimed invalid. Made it all lower case. Still claimed invalid. Removed the period. Still rejected. Examined their source code, but it looks to me like it should have accepted everything I tried except the first (which has five characters in the TLD).
<input id='Textbox-2'
data-sf-role="text-field-input"
type="email"
name="TextFieldController_0"
placeholder="Email"
value=""
pattern=\A[a-zA-Z0-9._%+-]+#(?:[a-zA-Z0-9-]+\.)+[a-zA-Z]{2,4}\z
class="form-control" />
(I added the line breaks to save y'all from lots of horizontal scrolling). Why is the pattern failing? Could it be the failure to surround it with quote marks?
\A and \z are anchors (start of string and end of string repspectively) that are not supported by JS regex flavor where ^ and $ are used. However, the HTML5 pattern regex is processed with HTML5 engine that wraps the pattern with ^(?: and )$, thus, anchoring the pattern by default.
You should make sure \A and \z are removed from the pattern:
pattern="[a-zA-Z0-9._%+-]+#(?:[a-zA-Z0-9-]+\.)+[a-zA-Z]{2,4}"
Related
I have an input field in my Angular component in which i want to not allow a user to be able to type a (space).
I've tried using
<input type="text" [(ngModel)]="inputText" pattern="[a-zA-Z]">
which wasn't what i wanted, and it didn't work anyways!
Does anybody know what the correct regex pattern to just block the (space) key is? And what is the correct way to use the pattern, as the above pattern didn't work...
Thanks in advance.
Using RegEx will still allow the user to type in space. But it will mark the field as invald if a pattern validator is applied to it.
If you don't really want to allow the user to type in space in the first place, you'll have to prevent it by listening to the keydown event on the input and then handling it to prevent its default behaviour. Here, give this a try:
<input type="text" (keydown.space)="$event.preventDefault()">
Here's also a Sample StackBlitz for your ref.
If you want to allow any type of character except spaces alone without any letters, you can use this:
"^\w+( +\w+)*$"
If you also want to use accented vowels, you can use this:
"^[a-zA-Zá-úÁ-Ú0-9]+( +[a-zA-Zá-úÁ-Ú0-9]+)*$"
You can use the following pattern:
<input pattern="[^\s]*">
[^\s] is a negative set which matches every character which is not in the set.
\s matches a white space character (e.g. space, tab, etc.)
* matches 0 or more character of the preceding item
Here is an example of how the browser checks if the pattern is correct (i.e. Google Chrome for example does not allow you to submit the form if there is a whitespace character in it. Test it here (enter a string containing a white space and hit Submit):
<form>
<input pattern="[^\s]*">
<button type="submit">Submit</button>
</form>
The best way of addressing this problem is by writing the directive which you can use on multiple locations.
Here is the Stackblitz sample for the same
My HTML has the following input element (it is intended to accept email addresses that end in ".com"):
<input type="email" name="p_email_ad" id="p_email_ad" value="" required="required" pattern="[\-a-zA-Z0-9~!$%\^&*_=+}{\'?]+(\.[\-a-zA-Z0-9~!$%\^&*_=+}{\'?]+)*#([a-zA-Z0-9_][\-a-zA-Z0-9_]*(\.[\-a-zA-Z0-9_]+)*\.([cC][oO][mM]))(:[0-9]{1,5})?$" maxlength="64">
At some point in the past 2 months, Chrome has started returning the following JavaScript error (and preventing submission of the parent form) when validating that input:
Pattern attribute value
[\-a-zA-Z0-9~!$%\^&*_=+}{\'?]+(\.[\-a-zA-Z0-9~!$%\^&*_=+}{\'?]+)*#([a-zA-Z0-9_][\-a-zA-Z0-9_]*(\.[\-a-zA-Z0-9_]+)*\.([cC][oO][mM]))(:[0-9]{1,5})?$
is not a valid regular expression: Uncaught SyntaxError: Invalid
regular expression:
/[\-a-zA-Z0-9~!$%\^&*_=+}{\'?]+(\.[\-a-zA-Z0-9~!$%\^&*_=+}{\'?]+)*#([a-zA-Z0-9_][\-a-zA-Z0-9_]*(\.[\-a-zA-Z0-9_]+)*\.([cC][oO][mM]))(:[0-9]{1,5})?$/: Invalid escape
Regex101.com likes the regex pattern, but Chrome doesn't. What syntax do I have wrong?
Use
pattern="[-a-zA-Z0-9~!$%^&*_=+}{'?]+(\.[-a-zA-Z0-9~!$%^&*_=+}{'?]+)*#([a-zA-Z0-9_][-a-zA-Z0-9_]*(\.[-a-zA-Z0-9_]+)*\.([cC][oO][mM]))(:[0-9]{1,5})?"
The problem is that some chars that should not be escaped were escaped, like ' and ^ inside the character classes. Note that - inside a character class may be escaped, but does not have to when it is at its start.
Note also that HTML5 engines wraps the whole pattern inside ^(?: and )$ constructs, so there is no need using $ end of string anchor at the end of the pattern.
Test:
<form>
<input type="email" name="p_email_ad" id="p_email_ad" value="" required="required" pattern="[-a-zA-Z0-9~!$%^&*_=+}{'?]+(\.[-a-zA-Z0-9~!$%^&*_=+}{'?]+)*#([a-zA-Z0-9_][-a-zA-Z0-9_]*(\.[-a-zA-Z0-9_]+)*\.([cC][oO][mM]))(:[0-9]{1,5})?" maxlength="64">
<input type="Submit">
</form>
I was experiencing the same issue with my application but had a slightly different approach to a solution. My regex has the same issue that the accepted answer describes (special characters being escaped in character classes when they didn't need to be), however the regex I'm dealing with is coming from an external source so I could not modify it. This kind of regex is usually fine for most languages (passes validation in PHP) but as we have found out it breaks with HTML5.
My simple solution, url encode the regex before applying it to the input's pattern attribute. That seems to satisfy the HTML5 engine and it works as expected. JavaScript's encodeURIComponent is a good fit.
I can't seem to put together a working pattern to disallow all html tags except for the strong and em tag.
I don't want to parse the html but just want to give the user a warning that the input will not be accepted. I am aware that this is not supported in all browsers but I would love a pure html solution, as I already have a working JS solution, but I wan't to layer the user experience.
<input name="user_input" pattern="^(?!<[^>]*>).*$" />
So allowed tags: strong, em
the use of all other tags should make the result false
Any one able to crack this one?
KR
edit:
<input type="text" pattern="((?!<(?!\/?(strong|em))[^>]*>).)*">
is what seems to do the trick. Thank you for your help!
You can use a Negative Lookahead (?!) for this purpose.
An example regex string which matches the entire pair:
<(?!\/?strong|\/?em)[^>]*>.*(?:<\/.*?>)?
A shorter regex, which matches the first tag only
<(?!\/?(strong|em))[^>]*>
This match will pass if a HTML tag with something EXCEPT strong or em exists.
So, if match = $true, you can deny the input and give the user a warning.
Regex101 demo
I am trying to get an angular ng-pattern to check that a username has no whitespaces or special characters. The following form return false if you enter whitespaces or special characters. However, it becomes true as soon as you enter a-z, A-z or 0-9. I have tried ng-pattern="/[^\s]+/" and \S and [^ ] but they make no difference.
<form name="myform">
valid? {{ myform.$valid }}
<input type="text" name="username" ng-model="username" ng-pattern="/[a-zA-Z0-9^ ]/" required/>
</form>
Here's the form in a plunk: http://plnkr.co/edit/6T78kyUgXYfNAwB4RHKQ?p=preview
Try the following pattern:
/^[a-zA-Z0-9]*$/
This allows only alphanumeric characters.
To surface the specific answer I was looking for, I already had the pattern suggested by Sniffer /^[a-zA-Z0-9]*$/, but angular still appeared to ignore leading/trailing whitespace. As Cristian mentions in the comments:
Angular will trim the input model, meaning that the validation doesn't trigger for spaces. You can add an ng-trim="false" to the input to fix this.
Note that Angular is trying to protect you by silently trimming whitespace by default. In my case, I want the user to be aware that the trailing whitespace is invalid.
in case anyone needs to disallow user entering emails in the address field
ng-pattern="/^[^#]+$/"
<div ng-messages="vm.updateCC.mailingAddress.$error" ng-show="vm.updateCC.mailingAddress.$touched">
<p class="validation-message" ng-message="pattern">Please enter a valid address</p>
</div>
I'm trying to validate a form using a regular expression found here http://regexlib.com/. What I am trying to do is filter out all characters except a-z, commas and apostrophes. If I use this code:
<cfinput name="FirstName" type="text" class="fieldwidth" maxlength="90" required="yes" validateat="onsubmit,onserver" message="Please ensure you give your First Name and it does not contain any special characters except hyphens or apostrophes." validate="regular_expression" pattern="^([a-zA-Z'-]+)$" />
I get the following error: Unmatched [] in expression. I figured out this relates to the apostrophe because it works if I use this code(but does not allow apostrophes):
<cfinput name="FirstName" type="text" class="fieldwidth" maxlength="90" required="yes" validateat="onsubmit,onserver" message="Please ensure you give your First Name and it does not contain any special characters except hyphens or apostrophes." validate="regular_expression" pattern="^([a-zA-Z-]+)$" />
So I'm wondering is there some special way to escape apostrophes when using regular expressions?
EDIT
I think I've found where the problem is being caused (thanks to xanatos), not sure how to fix it. Basically CF is generating a hidden field to validate the field as follows:
<input type='hidden' name='FirstName_CFFORMREGEX' value='^([a-zA-Z'-]+)$'>
Because it is using single apostrophes rather than speech marks round the value, it is interpreting the apostrophe as the end of the value.
I think there is a bug in the cfinput implementation. It probably uses the string you pass in pattern in a Javascript Regex but it uses the ' to quote it. So it converts it in:
new Regex('^([a-zA-Z'-]+)$')
Try replacing the quote with \x27 (it's the code for the single quote)
The unmatched ] is because the hyphen is treated to mean a range between the two characters around it. Put the hyphen at the beginning as a best practice.
^([-a-zA-Z']+)$