Calling function from within Knockout Observable Array

Question

I have a Knockout observable array that I wish to edit from within Javascript and from the HTML as well. Here is my code:

var ListModel = function(formula) {
  var self = this;
  self.formula = ko.observableArray(formula);

  this.mergeEquation = function(op) {
    if (op.type == "ins") {
      self.formula.splice(op.position, 0, op.value);
    } else if (op.type == "del") {
      self.formula.splice(op.position, 1);
    } else {
      console.info("No match: " + op.value + op.position);
    }
  };
};

My variable op is a JSON string. I know how to call the mergeEquation function using HTML data-bind, but how do I do so from within the same JS file? My current code goes something like this:

ko.applyBindings(new ListModel(formula));
//...
//initializing of JSON object called op
//...
if (something) {
  mergeEquation(op);
}

but it doesn't work. Am I missing out some step here? I've read up on functions and extenders but both seems too overkill for what I'm trying to do here.

PS: Here's a sample of the JSON structure I'm working with:

{"type":"ins", "clientID":1223, "version":0, "value":"hi", "position":0, "id":2736}

you need to show the part where you create the ListModel, and where you try to call mergeEquation in relation to it :) — Keith Nicholas
– Keith Nicholas, Commented Jun 11, 2012 at 3:08

Keith Nicholas · Accepted Answer · 2012-06-11 03:11:32Z

3

change :-

ko.applyBindings(new ListModel(formula));

to

  var vm = new ListModel(formula);
   ko.applyBindings(vm);

so, now vm is the thing you can call the mergeequation on

vm.mergeEquation(op)

answered Jun 11, 2012 at 3:11

Keith Nicholas

44.4k15 gold badges101 silver badges168 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Calling function from within Knockout Observable Array

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related