pass number into Handlebars.template.foo(bar)

Question

I have a precompiled handlebars template and I would like to pass a variable containing a number into Handlebars.template.foo(bar). So it would look something like Handlebars.template.foo(bar, 1).

I would then like to be able to access that number so that I can pass it into my helper. so I would like to do

{{myHelper bar num}}
   {{something}}
{{myHelper}} 

I have the helper set up ready to receive the number and it does if I invoke {{myHelper bar 1}}, but its passing the number from the original javascript into the variable 'num' I am having trouble with.

here is my helper by request :

Handlebars.registerHelper('myHelper', function(bar, num){
    var ret = ""
    for(var i=0; i < bar.length; i++){
        if(bar[i].id == num)
           ret = ret + bar[i]  
    }
    return ret; 
});    

If you could please let me know if this is first of all possible and secondly how to do it.

thanks in advance.

Answer 1

Im not completely sure of what your issue is. But from what I understand you are trying to create a block helper like the built in 'each'.

If that's the case, your usage is wrong. Block helpers need to start with # and it ends with a /. So you helper would be used like

{{#myHelper items num}}
  {{something}}
{{/myHelper}}

If you want to dynamically look up a property inside the block helper, you will need to pass the context object to the function inside the options argument. Your helper will look like

Handlebars.registerHelper('myHelper', function(items, num, options){
  var ret = ""
  for(var i=0; i < items.length; i++){
      if(items[i].id === num) {
         ret = ret + options.fn(items[i]);
      }
  }
  return ret; 
});

To test out this helper I created a sample object like

{ 
  items: [{id: 1, something:'First Item'},
    {id: 2, something:'Second Item'},
    {id: 3, something:'Third Item'}
  ],
  num: 3
}

You can try this helper at the tryhandlbars and see if this is what you need.