HTML RegEx (First letter to be capitalized) - html

I have field "first and second name" and I need RegEx for capitalizing first letter in each word in this field.
With this pattern, only first word is capitalized, but second is not
<form action="/action_page.php">
First and Second name <input type="text" name="f_and_s_name" pattern="[A-zA-Z]{1,13}" title="">
<input type="submit">
</form>

The pattern="[A-zA-Z]{1,13}" pattern is parsed by the JS RegExp engine as ^(?:[A-zA-Z]{1,13})$. It matches a string that consists of 1 to 13 characters that are ASCII letters, and also [, \, ], ^, _, ` (see this answer for more details).
You plan to only validate strings that start with an uppercase ASCII letter followed with lowercase letters, then have a space, and then again an uppercase ASCII letter followed with lowercase letters.
Then, you may use
pattern="[A-Z][a-z]* [A-Z][a-z]*"
If you want to make the rule a bit less restricted, you may use [A-Z][a-zA-Z]*\s+[A-Z][a-zA-Z]* (this will also allow strings in ALLCAPS, and will allow any 1+ whitespace chars between two letter strings. If you plan to implement Unicode letter support, it will only be easy in latest Chrome versions (it will look like pattern="\p{Lu}\p{L}*\s+\p{Lu}\p{L}*"). However, it won't work in all other browsers that still do not support ECMA2018 standard.

Related

Password pattern wont accept this special characters like <>,./'";

I use this pattern in input tag type password to accept a strong password. "Must contain at least one number, one uppercase and lowercase letter, and one special character ,minimum of 8 characters, and maximum of 26 characters". But when I inserted one of these characters <>,./'"; the field title keep appearing. I would like to implement all special characters in my registration form
<form>
<input pattern="^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[#$!%*?&])[A-Za-z\d#$!%*?&]{8,}$" />
<input type="submit" />
</form>
(?=.*[0-9]) require one digit anywhere
(?=.*[a-z]) require one lowercase letter anywhere
(?=.*[A-Z]) require one uppercase letter anywhere
(?=.*[^0-9a-zA-Z]) require one symbol anywhere
^.{8,26}$ match any string of 8 to 26 characters
Combine all of these together and you get:
^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[^0-9a-zA-Z]).{8,26}$
This, of course, counts anything that isn't a letter from A to Z or a digit as a special character, including accented letters, letters from other alphabets, and whitespace.

Html5 input pattern check

i'm not good in html pattern validation.
I have this problem, my input text is valid only : min 3 max 30 chars,
white space at first and at end of the string is not allowed, is allowed white space between one word and another is allowed, is allowed A-Za-z, first char of word it must be Uppercase and the others word it must be Lowercase.
Thanks.
--UPDATE--
input#name
Valid Examples:
'Mario Giovanni'
'Maria'
'Jacopo Karol Pio'
'Jacopo K'
Invalid Examples:
' Mario Giovanni'
'Mario Giovanni '
' Mario Giovanni '
'Mario Giovanni'
'maria'
'mAria'
'Antonio mario'
If you need pure regex then this should work for you:
<input type="text" pattern="(?=^.{3,30}$)^[A-Z][a-z]*(?: [a-z]+)*$">
(?=^.{3,30}$) - use a positive lookahead to make sure we have between 3 and 30 chars
^[A-Z] - require start with a capital letter
[a-z]* - optionally allow lowercase letters to follow
(?: [a-z]+)* - optionally allow a repeating group of a space char follow by one or more letters
$ - end of string anchor
You will want to use a Regular Expression pattern to check whether the input is valid or not, as well as the maxlength and minlength attributes to ensure that the input is between 3 and 30 characters.
Regarding the RegEx pattern, we must:
Start at the beginning of the input: ^
Verify that the first character is between A and Z: [A-Z]
Verify that the following characters before the last one are lowercase letters or spaces: [a-z ]*, where * indicates that there might be multiple characters matching that part of the pattern; if you only want to allow one space between word, then use ([a-z]* ?)
Verify that the last character is a lowercase letter: [a-z]$, where $ indicates the end of the input
Below is the code I would use.
<input type="text" minlength=3 maxlength=30 pattern="^[A-Z][a-z ]*[a-z]$">
Looks like what you wait is:
<input type="text" pattern="(?=^.{3,30}$)^[A-Z][a-z]+( [A-Z][a-z]+)*$">
Notice this is being validated in the user browser, and doesn't configure a secure input validation. You should check the input again at server-side before using it anywhere.

Html regex pattern: [\d\s-]{3} works but [\d-\s]{3} doesn't. Why?

Codepen example:
https://codepen.io/Trost/pen/KXBRbY
Try putting 1 symbol in both fields.
I can't get what's wrong. If I test these regex in https://regex101.com, they appear to be identical.
<form>
Works: <input type="text" name="country_code" pattern="[\d\s-]{3}" title="-23" required>
<input type="submit">
</form>
<form>
Bug: <input type="text" name="country_code" pattern="[\d-\s]{3}" title="- 3" required>
<input type="submit">
</form>
The real root cause here is that the regex [\d-\s] is used in the pattern HTML5 attribute, and in the latest versions of Chrome and FireFox is compiled as an ES2015-compatible regex with the u modifier. The consequence is that there are much stricter escaping rules for the Unicode regex patterns.
What it means is whenever a char cannot be parsed unambiguously, it is an error. When a char is escaped, but does not need escaping, it is again an error.
The chars that you may escape in the character class inside a u based regex are +, $, ^, *, (, ), |, \, [, ], ., ?, -, {, } (see this source). If the - is at the start/end of the character class, it still can go unescaped, as it can only be parsed as a literal hyphen there.
In between two shorthand character classes, an unescaped - will produce an error because it is treated as a user error.
So, either place a hyphen at the start/end (it is always the best option), or escape it inside the character class (and never escape it outside of the character class).
You define two different things:
[a-z] is a definition of a range - all characters from a to z.
[az-] is a definition of a set of three elements - a, z and
-.

Firefox input pattern regex range

This is related to the same problem as this question:
Firefox error: Unable to check input because the pattern is not a valid regexp: invalid identity escape in regular expression
When using escaped characters in the <input> pattern attribute, Firefox throws these errors to the console:
Unable to check <input
pattern='^[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEFa-zA-Z\s\'-]{1,50}$'>
because the pattern is not a valid regexp: invalid identity escape in
regular expression
So when using the pattern attribute on an <input> field, the unicode characters no longer need to be escaped. In that case the user simply needs to stop escaping their characters and change \#\% to #%, problem solved.
I've got this somewhat more complicated regex pattern, what do I change it to to work in Firefox?
<input type="text" pattern="^[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEFa-zA-Z\s\'-]{1,50}$">
Essentially it's allowing for any string between 1..50 characters in length as long as all the characters are within these ranges:
\u00A0-\uD7FF
\uF900-\uFDCF
\uFDF0-\uFFEF
a-z
A-Z
as well as whitespace, apostrophes and hyphens. A quick search sees the \u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEFa part of it fairly widely used in all sorts of regexes. I just don't see exactly what to use instead of the escaped unicode character references here.
You need to remove the escaping backslash before the single quote.
Note that in a regular HTML5 pattern field, one does not have to use ^ and $ anchors at the pattern start/end as the HTML5 pattern attribute encloses the passed pattern with ^(?: and )$. However, as per your feedback, the Abide validation circumvents this and passes unanchored pattern to the regex engine. Thus, you should keep the anchors.
<input type="text" pattern="^[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEFa-zA-Z\s'-]{1,50}$">
A quick demo:
<form>
<input type="text" pattern="[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEFa-zA-Z\s'-]{1,50}">
<input type="submit">
</form>

HTML Validation pattern for any Aplha Character (including special chars like üöä) hyphes and spaces [duplicate]

This question already has answers here:
Regex to match only letters
(20 answers)
Closed 8 years ago.
I'm trying to create a regex for a HTML5 input so a user can only insert alpha characters that may be in a name. So characters from a-z, but also including ö,ü,â,æ ... and so on whilst also allowing whitespace and hyphens .
I have played around with some pattens but nothing seems to work correctly, this is what I have so far: <input type="text" name="firstname" pattern="[a-zA-Z\x7f-\xff] " title="">
Does anyone have a quick answer for this?
Since the HTML5 pattern attribute uses the same regex syntax as JavaScript, there is no simple way to refer to all alphabetic characters. You would need to write a rather huge expression (and to update it as new alphabetic characters are added to Unicode). You would need to start from the Unicode character database and the definition of General Category of characters there, or rely on someone having done that for you.
However, for your practical purposes, testing for “alpha characters that may be in a name” is even more complex. There are non-alphabetic characters used in names, such as left single quotation mark (‘) in addition to normal quotation mark (’), and who knows what characters there might be? If this is about people’s real names, it is very difficult to impose restrictions that do not discriminate. If this is about user names in a system, for example, you can define the repertoire as you like, but [a-zA-Z\x7f-\xff] does not look adequate (it includes some control characters and some non-alphabetic characters and excludes many Latin letters commonly used in Europe).
There is a very simple method to apply all you RegEx logic(that one can apply easily in English) for any Language using Unicode.
For matching a range of Unicode Characters like all Alphabets [A-Za-z] we can use
[\u0041-\u005A] where \u0041 is Hex-Code for A and \u005A is Hex Code for Z
'matchCAPS leTTer'.match(/[\u0041-\u005A]+/g)
//output ["CAPS", "TT"]
In the same way we can use other Unicode characters or their equivalent Hex-Code according to their Hexadecimal Order (eg: \u0100–\u017FF) provided by unicode.org
Try: [À-ž] as an example of Range. Modify your Range according to your requirement.
It will match all characters between À and ž.
Sample regEx would be
/[A-Za-zÀ-ž\-\s]+/
For more Ref: Latin Unicode Character