CODEWITHSUNDEEP
javascriptjqueryvalidationknockout.js
Paritosh Piplewar
Paritosh Piplewar

Reputation: 8132

knockout optional validation with max-size and custom validator?

I have one VM which has multiple forms with all validation. To support multiple forms i think i have to implement knockout optional validation. There are many validations in my forms. Like maxLength , minlength ,required and one custom validation.

The validations looks like this

@password = ko.observable("").extend({ required: true, minLength: 5})
@current_password = ko.observable().extend({
      validation: { validator: @mustEqual, message: 'Passwords do not match.', params: @password }
    })

Now, to make the above validation optional with isLoggedIn i use this 

@password  = ko.observable().extend
  required:
    onlyIf: () =>
      !@isLoggedIn()

but it only works for required . i also want it for minLength and for custom validator . How to do that ?

Upvotes: 1

Views: 2679

Answers (1)

pax162
pax162

Reputation: 4735

onlyIf can be used with all validators, like this (fiddle, forked from github examples: http://jsfiddle.net/LYP5u/25/):

 self.testField = ko.observable(5).extend({
        max:{
            onlyIf:function() { return self.country() === 'US'},
            params:5
        }
    });

Example from validation source: https://github.com/Knockout-Contrib/Knockout-Validation/blob/master/Src/api.js#L225

Conditional validation docs: https://github.com/Knockout-Contrib/Knockout-Validation/wiki/Conditional-Validation-with-onlyIf-parameter

Maybe we should talk to one of the maintainers to make this more clear in the manual, perhaps add some examples with onlyIf to this page https://github.com/Knockout-Contrib/Knockout-Validation/wiki/Native-Rules

Upvotes: 3

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