Rendering dynamic parameters in a dust.js helper

gistfile1.js

// Handy function to render dynamic parameters in a dust.js helper
function renderParameter(name, chunk, context, bodies, params) {
	if (params && params[name]) {
		if (typeof params[name] === "function") {
			var output = "";
			chunk.tap(function (data) {
				output += data;
				return "";
			}).render(params[name], context).untap();
			return output;
		} else {
			return params[name];
		}
	}
	return "";
}

// Example
// Template
<div>
  {@MyHelper single="{id}" comp="{type}_{id}" text="example" /}
</div>

// Data
{type: "myType", id: "42"}

// Helper
dust.helpers["MyHelper"] = function (chunk, context, bodies, params) {
  var single = renderParameter("single", chunk, context, bodies, params); // single = "42"
  var comp = renderParameter("comp", chunk, context, bodies, params); // single = "myType_42"
  var text = renderParameter("text", chunk, context, bodies, params); // text = "example" -> this is not necessary, access params.text directly
  <...your code here>
  return chunk;
}

Very useful, thanks

A much simpler way resolve a variable is:

var single = context.resolve(params.single);

From http://stackoverflow.com/questions/32465011/how-to-pass-a-variable-into-a-dust-helper-function-key