ngMaterial Layout Directives used to create Layout class selectors instead of attribute selectors

layout.js

(function () {

  'use strict';

  angular.module('material.layouts', ['material.core'])

      // Attribute directives with optional value(s)

      .directive('layout'              , attribute_withValue('layout'      , true)  )
      .directive('layoutSm'            , attribute_withValue('layout-sm'   , true)  )
      .directive('layoutGtSm'          , attribute_withValue('layout-gt-sm', true)  )
      .directive('layoutMd'            , attribute_withValue('layout-md'   , true)  )
      .directive('layoutGtMd'          , attribute_withValue('layout-gt-md', true)  )
      .directive('layoutLg'            , attribute_withValue('layout-lg'   , true)  )
      .directive('layoutGtLg'          , attribute_withValue('layout-gt-lg', true)  )

      .directive('flex'                , attribute_withValue('flex'        , true)  )
      .directive('flexSm'              , attribute_withValue('flex-sm'     , true)  )
      .directive('flexGtSm'            , attribute_withValue('flex-gt-sm'  , true)  )
      .directive('flexMd'              , attribute_withValue('flex-md'     , true)  )
      .directive('flexGtMd'            , attribute_withValue('flex-gt-md'  , true)  )
      .directive('flexLg'              , attribute_withValue('flex-lg'     , true)  )
      .directive('flexGtLg'            , attribute_withValue('flex-gt-lg'  , true)  )

      // Attribute directives with optional value(s) but directiveName is NOT added as a class

      .directive('layoutAlign'         , attribute_withValue('layout-align')        )
      .directive('layoutAlignSm'       , attribute_withValue('layout-align-sm')     )
      .directive('layoutAlignGtSm'     , attribute_withValue('layout-align-gt-sm')  )
      .directive('layoutAlignMd'       , attribute_withValue('layout-align-md')     )
      .directive('layoutAlignGtMd'     , attribute_withValue('layout-align-gt-md')  )
      .directive('layoutAlignLg'       , attribute_withValue('layout-align-lg')     )
      .directive('layoutAlignGtLg'     , attribute_withValue('layout-align-gt-lg')  )

      .directive('flexOrder'           , attribute_withValue('flex-order')          )
      .directive('flexOrderSm'         , attribute_withValue('flex-order-sm')       )
      .directive('flexOrderGtSm'       , attribute_withValue('flex-order-gt-sm')    )
      .directive('flexOrderMd'         , attribute_withValue('flex-order-md')       )
      .directive('flexOrderGtMd'       , attribute_withValue('flex-order-gt-md')    )
      .directive('flexOrderLg'         , attribute_withValue('flex-order-lg')       )
      .directive('flexOrderGtLg'       , attribute_withValue('flex-order-gt-lg')    )

      .directive('offset'              , attribute_withValue('offset')              )
      .directive('offsetSm'            , attribute_withValue('offset-sm')           )
      .directive('offsetGtSm'          , attribute_withValue('offset-gt-sm')        )
      .directive('offsetMd'            , attribute_withValue('offset-md')           )
      .directive('offsetGtMd'          , attribute_withValue('offset-gt-md')        )
      .directive('offsetLg'            , attribute_withValue('offset-lg')           )
      .directive('offsetGtLg'          , attribute_withValue('offset-gt-lg')        )

      // Attribute directives with no value(s )

      .directive('layoutMargin'        , attribute_noValue('layout-margin')         )
      .directive('layoutPadding'       , attribute_noValue('layout-padding')        )
      .directive('layoutWrap'          , attribute_noValue('layout-wrap')           )
      .directive('layoutFill'          , attribute_noValue('layout-fill')           )

      .directive('hide'                , attribute_noValue('hide')                  )
      .directive('hideSm'              , attribute_noValue('hide-sm')               )
      .directive('hideGtSm'            , attribute_noValue('hide-gt-sm')            )
      .directive('hideMd'              , attribute_noValue('hide-md')               )
      .directive('hideGtMd'            , attribute_noValue('hide-gt-md')            )
      .directive('hideLg'              , attribute_noValue('hide-lg')               )
      .directive('hideGtLg'            , attribute_noValue('hide-gt-lg')            )
      .directive('show'                , attribute_noValue('show')                  )
      .directive('showSm'              , attribute_noValue('show-sm')               )
      .directive('showGtSm'            , attribute_noValue('show-gt-sm')            )
      .directive('showMd'              , attribute_noValue('show-md')               )
      .directive('showGtMd'            , attribute_noValue('show-gt-md')            )
      .directive('showLg'              , attribute_noValue('show-lg')               )
      .directive('showGtLg'            , attribute_noValue('show-gt-lg')            );

    /**
     * Creates a registration function with Directive postLink function
     * for ngMaterial Layout attribute directive
     *
     * Note: This provides easy translation to switch ngMaterial
     * attribute selectors to CLASS selectors and directives.
     *
     * !! This is important for IE Browser performance
     *
     * @param classname String like flex-gt-md
     * @param addDirectiveAsClass Boolean
     */
    function attribute_withValue(className, addDirectiveAsClass) {
        return [function() {
            return {
                link: function(link, element, attrs) {
                    var directive = attrs.$normalize(className);
                    if (addDirectiveAsClass)  element.addClass(className);
                    if (attrs[directive])     element.addClass(className + "-" + attrs[directive].replace(/ \s*/g, "-"));
                }
            };
        }];
    }

    function attribute_noValue(className) {
        return [function() {
            return {
                link: function(link, element, attrs) {
                    element.addClass(className);
                }
            };
        }];
    }

})();

This is an excellent improvement; I completely forgot that $normalize() is a function within attrs.
I also always forget to camelCase the directive registration name...

Don't forget to update the RegEx:

element.addClass(className + "-" + attrs[directive].replace(/ \s*/g, "-"));

Thanks!