Knockout validation

Kurkula picture Kurkula · Jan 25, 2012 · Viewed 100.6k times · Source

I have asp.net mvc3 project where I do a bulk edit on a table with knockout binding. I want to do validations like required and number validations while saving data. Is there any easier way to do knock out validations. PS: I am not using forms.

Answer

Cohen picture Cohen · Mar 5, 2012

Have a look at Knockout-Validation which cleanly setups and uses what's described in the knockout documentation. Under: Live Example 1: Forcing input to be numeric

You can see it live in Fiddle

UPDATE: the fiddle has been updated to use the latest KO 2.0.3 and ko.validation 1.0.2 using the cloudfare CDN urls

To setup ko.validation:

ko.validation.rules.pattern.message = 'Invalid.';

ko.validation.configure({
    registerExtenders: true,
    messagesOnModified: true,
    insertMessages: true,
    parseInputAttributes: true,
    messageTemplate: null
});

To setup validation rules, use extenders. For instance:

var viewModel = {
    firstName: ko.observable().extend({ minLength: 2, maxLength: 10 }),
    lastName: ko.observable().extend({ required: true }),
    emailAddress: ko.observable().extend({  // custom message
        required: { message: 'Please supply your email address.' }
    })
};