Use

A helpers expression calls a function looked up in the [can-view-scope.Options helpers scope] followed by the scope. It looks like:

<!-- Template -->
<h1>{{pluralize type ages.length}}</h1>

{
    pluralize: function( type, count ) {
        return "data-pluralize";
    },
    todos: new List( [ 22, 32, 42 ] ),
    type: "age"
}

{
    pluralize: function( type, count ) {
        return type + ( count() === 1 ? "" : "s" );
    }
}

<!-- Result -->
<h1>Ages</h1>

Helper expression arguments that are observable are passed a compute. This is in contrast to Call expressions that get passed the value.

Helper expression arguments are space separated. If a Hash expression is an argument, the hash properties and values will be added to the helper options object. For example:

<!-- Template -->
<h1>{{pluralize word=type count=ages.length}}</h1>

{
    todos: new List( [ 22, 32, 42 ] ),
    type: "age"
}

{
    pluralize: function( helperOptions ) {
        return helperOptions.hash.type + ( helperOptions.hash.count() === 1 ? "" : "s" );
    }
}

<!-- Result -->
<h1>Ages</h1>