How to use a converter in an jsview if statement?

Question

So, i'm simply trying to convert an int to a bool inside of an "if" statement. I'm unsure on how to achieve this. My code that I was playing with is below.

JsFiddle code here

The HTML:

<div id="main-div"></div>

<script id="testTmpl" type="text/x-jsrender">
    <input data-link="{:test:}" />
    <div data-link="{intToBool:test:}"></div>

    // testing different methods, none seem to work
    {^{if intToBool:test }}
        Woot! 1
    {{/if}}
    {^{if intToBool(test) }}
        Woot! 2
    {{/if}}
    {^{if ~root.intToBool(test) }}
        Woot! 3
    {{/if}}
</script>

The JavaScript:

 $.views.converters({
    intToBool: function(val) {
      if (val === 0 || val === false || val === '0' || val === 'false') {
        return false;
      } else {
        return true;
      }
    }
  });

  function App(data) {
    self = this;

    self.test = 0;
  };

  var app = new App();

  var testTmpl = $.templates("#testTmpl");
  testTmpl.link("#main-div", app);

Answer 1

Registering converters is only for use with the {{: ...}} tag (http://www.jsviews.com/#assigntag) in it's various forms {{cvt:expression}} {^{cvt:expression}} <div data-link="{cvt:expression}"> or <input data-link="{cvt:expression:cvtBack}" />. See http://www.jsviews.com/#converters.

For other scenarios you need to use either a method {^{if someMethodOnMyModel(test)}} or a helper (http://www.jsviews.com/#helpers): {^{if ~someHelper(test)}}.

See also http://www.jsviews.com/#samples/jsr/paths for examples of helper paths - ~some.expression... - to either helper function or helper objects. Note that ~root is a built-in helper path to the top-level data object that you passed in to render() or link().

Edit: In fact there is a little-known feature in JsRender and JsViews which does let you associate registered converters with other tags. You can write

{^{if test convert="intToBool" }}
    Woot!
{{/if}} 

But generally it may be simpler/better to use ~intToBool(test) - which is more familiar, and perhaps easier to understand when reading the template.

Also BTW {{if test}} tests on 'truthy' so test does not need to be of type boolean. OTOH if you want to make "false", or "0" be falsey, then you will indeed need a helper/converter.