问题
I am struggling writing a Regex for angular ng-pattern to validate a form input field.An example of the possible inputs are below
Valid input:
@tag1,@tag2,@tag3
@tag1, @tag2, @tag3
@tag1
Invalid Input:
@tag 1
@tag 1, @tag2, @tag -3
@ta g1, @t ag2
Basically it should allow comma and comma whitespace, but not allow whitespace in between tags.
I have written a REGEX that matches all the invalid input, but when I use this in ng-pattern it does not do the correct validation.
Regex Built: /((^, @|@\s+)|@*[a-zA-Z0-9]* +[a-zA-Z0-9])/g
Link: https://regex101.com/r/HMVdLD/1
Any help is much appreciated!
回答1:
I suggest defining a pattern to match valid inputs, like
ng-pattern="/^@[a-zA-Z0-9]+(?:,\s*@[a-zA-Z0-9]+)*$/"
See the regex demo
If you want to disallow leading and trailing whitespace, add ng-trim="false".
Pattern details:
^- start of string@- a literal@symbol[a-zA-Z0-9]+- 1+ alphanumerics(?:,\s*@[a-zA-Z0-9]+)*- 0+ sequences of:,- comma\s*- 0+ whitespaces@[a-zA-Z0-9]+- same as above
$- end of string.
来源：https://stackoverflow.com/questions/43392494/angularjs-ng-pattern-regex