Function generateClasses generates classes string from a passed object

generate-classes.js

/* generateClasses generates classes string from a passed object, i.e.
    generateClasses({
      'class1': true,
      'class2': false,
      'class3': true
    });
    // will return string 'class1 class3'
*/

(function() {
  this.generateClasses = function generateClasses(classesObject) {
    var cl = [], clName;

    if(typeof classesObject !== 'object') {
      return;
    }

    for(clName in classesObject) {

      if(classesObject[clName] === true) {
        cl.push(clName);
      }
    }

    return cl.join(' ');
  };
}).call(this);