Calling a handlebars block helper from another helper

Question

How can I call a handlebars block helper from another helper in ember.

I am interested in converting the following in a bound helper.

    {{#each link in sideMenuLinks}}
        <li class="navigation page">
            {{#linkTo ROUTE_VARIABLE link.linkToRouteContext}}
                {{{link.iconTag}}}<i class="icon-right-open"></i>{{link.linkText}}</a>
            {{/linkTo}}
        </li>
    {{/each}}

Note that I will have to call a {{#linkTo}} block inside the helper and also change ROUTE_VARIABLE with a value from the property link.linkToRoute.

Answer 1

The Ember handlebars helpers are placed at Ember.Handlebars.helpers. You can call them with Ember.Handlebars.helpers.{helperName}.call.

However, The above looks like a dynamic partial/view style helper. I would suggest creating a Handlebars View helper for it. The syntax is similar but you pass in a View class to the helper.

  Ember.Handlebars.helper('sideMenuLinks', App.SideMenuLinksView);

The corresponding view can use a template similar to yours by giving a templateName

  App.SideMenuLinksView = Ember.View.extend({
    templateName: 'sideMenuLinksTemplate'
  });

You template would be something like,

 <script type='text/x-handlebars' data-template-name='sideMenuLinksTemplate'>
   {{#each link in view.links}}
       <li class="navigation page">
           {{#linkFor parentView.routeVariable link.linkToRouteContext}}
               {{{link.iconTag}}}<i class="icon-right-open"></i>{{link.linkText}}</a>
           {{/linkFor}}
       </li>
   {{/each}}    
 </script>

The default Ember linkTo is static, In that you cannot pass the named route from a variable. You will need a dynamic linkTo helper like the linkFor that looks up the variable path before applying linkTo internally.

  Ember.Handlebars.registerHelper('linkFor', function(path, params, options) {
    var view = options.data.view;
    var name = view.get(path);
    var args = [name, params, options];

    return Ember.Handlebars.helpers.linkTo.apply(this, args);
  });

Finally you can use this helper like below. The links property will be bound to the content of the controller in this example.

 <script type='text/x-handlebars' data-template-name='application'>
   {{sideMenuLinks links=content routeVariable='page'}}
 </script>

Here's a working jsbin.