Handlebars truncate helper method

truncate.js

Handlebars.registerHelper('truncate', function(length, value, opts) {
  // Make sure value exists
  if (value != null) {
    // Don't truncate if already short
    if (value.length <= length) {
      return value;
    }
    
    // Truncate to length and add ellipsis
    return value.substring(0, length) + '...';
  }
  
  return '--';
});

Usage

In Handlebars:

{{truncate 10 'Hello World'}} {{! Output: Hello Worl... }}
{{truncate 12 'Hello World'}} {{! Output: Hello World }}