Question

I have a form (new poll form) in which I can add multiple items (poll questions) to a collection using KnockoutJS. I want to know how can I force the user to enter a value into the question textbox before he can add a new row…

var App = function (pollData, pollQuestionData) {
             var self = this;
             self.poll = new Poll(pollData);
             self.questions = ko.observableArray([new PollQuestion(pollQuestionData)]); // Put one question in by defaul

             // Add new question function... here should go validation I guess???

             self.addQuestion = function () {
                 self.questions.push(new PollQuestion(pollQuestionData))
             };

             // Remove question function
             self.removeQuestion = function (question) {
                 self.questions.remove(question)
             };
         };

Here is my jsfiddle code (that by the way I couldn’t make it run…)

http://jsfiddle.net/AcE2V/3/

Answer 1

Here is a fiddle that uses a computed observable to only show the New Question button when all questions have a value:

http://jsfiddle.net/jearles/AcE2V/5/