CODEWITHSUNDEEP
expressconditional-statementsexpress-validator
Biku7
Biku7

Reputation: 470

How to use conditional validation - 'greater than' and 'less than' with express-validators in express.js?

I am using handlebar page as template and nodejs for backend.

I want to use the condtional validation if (a < b) then show error msg on webpage. But I am unable to do so with express-validators.

This is my below code I am trying its not working. I am using 2 letters keyword = 'lt' indeed but its not working.

  router.post('/addtasks', function(req, res, next) {
  req.checkBody('topic', 'Empty Topic').notEmpty();
  req.checkBody('website', 'Empty Website').notEmpty();

 req.checkBody('words', 'Empty Words').notEmpty().isLength({ min: 3 }).isInt({ lt: 2000});
});

The first 2 are working throwing error msg on webpage. But the 3rd one is not working. Is there also any other way or express package from which I can achieve this? Thanks!

EDIT FOR WHAT I AM TRYING:

  router.post('/addtasks', function(req, res, next) {
      req.checkBody('topic', 'Empty Topic').notEmpty();
      req.checkBody('website', 'Empty Website').notEmpty();
var totalCount = 2000;
totalCount = totalCount - 500;
    
  req.checkBody('words', 'Empty Words or Min. Words = 500 Required or either Word limit exceeded').notEmpty().isInt({ gt:500, lt: totalCount});

    });

Here I want to put the lt: value dynamically which keeps changing every time not fixed. but here its not taking that. I need a proper solution for this.

Upvotes: 1

Views: 8183

Answers (1)

BENARD Patrick
BENARD Patrick

Reputation: 30985

Express-validator uses the validator.js library.

Following its documentation

You should use min and max properties

req.checkBody('words', 'Empty Words').notEmpty().isInt({ min:100, max: 2000});

Extract :

check if the string is an integer.

options is an object which can contain the keys min and/or max to check the integer is within boundaries (e.g. { min: 10, max: 99 }). options can also contain the key allow_leading_zeroes, which when set to false will disallow integer values with leading zeroes (e.g. { allow_leading_zeroes: false }). Finally, options can contain the keys gt and/or lt which will enforce integers being greater than or less than, respectively, the value provided (e.g. {gt: 1, lt: 4} for a number between 1 and 4).

Upvotes: 7

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