Regex to validate the conditions evaluation logic which is defined by User

Question

I'm working on a logic where user defined multiple conditions to validate and then they also defined in what manner that condition should evaluate, understand it like this, User defined 4 different conditions and when user defined the evaluation criteria, it defined like ((1 AND 2 AND 3) OR 4), So I wanted to validate that evaluation criteria with the help of regex, I build following function,

function validateCustomLogic(ele){
    var msg = '';
    var isError = false;
    var eleVal =  $(ele).val();
    if(typeof eleVal != 'unknown' && typeof eleVal != 'undefined' && eleVal != null && eleVal != ''){
        var regEx = /^([(]*[1-9]+[ ][AND|OR]\w*[ ][1-9]*[)]*)*$/gi;
        var matchEle = eleVal.match(regEx);
        if(matchEle == null){
           isError = true;
        }
    }
    else{
        isError = true;                
    }

    return isError;
}

this function called on my input change where user defined the evaluation criteria,

<input onchange="validateCustomLogic(this)"  type="text" />

my regex /^([(]*[1-9]+[ ][AND|OR]\w*[ ][1-9]*[)]*)*$/gi works for some pattern identification but not for all, below is the tested result,

Input                         Result            Expected Result
1 AND 2 AND 3 AND 4           Error: false      false 
1 AND 2 AND (3 AND 4)         Error: false      false 
1 AND 2 AND 3 (AND 4)         Error: true       true  
(1 AND 2 AND 3 AND 4          Error: false      true*
)1 AND 2 AND 3 AND 4          Error: true       true
(1 AND 2 AND 3) AND 4         Error: true       false*
(1 AND 2)(AND 3 AND 4)        Error: true       true
((1 AND 2 AND 3 AND 4)        Error: false      true*

If you see the test result some of the entries with * are not satisfied with this regex, not sure what I'm missing over here. Can anyone help me to validate that.

You might wanna keep track of number of opening and closing brackets. — Shub, May 24 '18 at 07:25
I know regex might not be do that work on number of opening and closing brackets, but still it should satisfy the `(1 AND 2 AND 3) AND 4` condition, but am open to have other suggestions as well, a logic who do everything — user2809299, May 24 '18 at 07:28
check this [answer](https://stackoverflow.com/questions/133601/can-regular-expressions-be-used-to-match-nested-patterns) — Shub, May 24 '18 at 07:48
`^($)?(?:[1-9]+[ ][AND|OR]\w*[ ][1-9]*)*(?(1)$)$` using conditional regex to validate 1st level of brackets. — Shub, May 24 '18 at 07:49
I tried, but it seems to be some issue in the regex, have you validate it on https://regexr.com/ — user2809299, May 24 '18 at 09:19
As such there is no restriction I've build in the code, its up to user how many conditions are there and how complex the evaluation criteria for those conditions — user2809299, May 25 '18 at 06:50

Piterden · Answer 1 · 2019-04-30T02:53:50.423

0

https://regex101.com/r/anq7Mc/2

/^\((\d+\)? (AND|OR) )+\d+(\)|\) .*?)$|^(\(?\d+\)? (AND|OR) )+\d+(\)|\) .*?)$|^(\d+ (AND|OR) )+\d+$/

This match all you need

edited Apr 30 '19 at 02:53

answered Apr 30 '19 at 02:13

Piterden

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Regex to validate the conditions evaluation logic which is defined by User

1 Answers1