handlebars.js/lib/handlebars/utils.js

var Handlebars = {};

// BEGIN(BROWSER)
Handlebars.Exception = function(message) {
  this.message = message;
};

// Build out our basic SafeString type
Handlebars.SafeString = function(string) {
  this.string = string;
};
Handlebars.SafeString.prototype.toString = function() {
  return this.string.toString();
};

(function() {
  var escape = {
    "<": "&lt;",
    ">": "&gt;",
  };

  var badChars = /&(?!\w+;)|[<>]/g;
  var possible = /[&<>]/

  var escapeChar = function(chr) {
    return escape[chr] || "&amp;"
  };

  Handlebars.Utils = {
    escapeExpression: function(string) {
      // don't escape SafeStrings, since they're already safe
      if (string instanceof Handlebars.SafeString) {
        return string.toString();
      } else if (string === null) {
        string = "";
      }

      if(!possible.test(string)) { return string; }
      return string.replace(badChars, escapeChar);
    },

    isEmpty: function(value) {
      if (typeof value === "undefined") {
        return true;
      } else if (value === null) {
        return true;
      } else if (value === false) {
        return true;
      } else if(Object.prototype.toString.call(value) === "[object Array]" && value.length === 0) {
        return true;
      } else {
        return false;
      }
    }
  };
})();
// END(BROWSER)

exports.Utils = Handlebars.Utils;
exports.SafeString = Handlebars.SafeString;
exports.Exception = Handlebars.Exception;