Snap.svg addClass and removeClass

snapclass.js

Snap.plugin( function( Snap, Element, Paper, global ) {

  Element.prototype.addClass = function( klasses ) {

    if ( !( klasses instanceof Array ) ) { klasses = [ klasses ]; }
    var currentKlasses = ( this.attr( 'class' ) || '' ).split( ' ' );

    if ( currentKlasses === [ '' ] ) {
      this.attr({ 'class': klasses.join( ' ' ) });
      return this;
    }

    for ( var i = 0, klass; klass = klasses[ i ++ ]; ) {
      if ( currentKlasses.indexOf( klass ) === -1 ) {
        currentKlasses.push( klass );
      }
    }

    this.attr({ 'class': currentKlasses.join( ' ' ) });
    return this;
  };

  Element.prototype.removeClass = function( klasses ) {
    var ind, currentKlasses;

    if ( !( klasses instanceof Array ) ) { klasses = [ klasses ]; }
    currentKlasses = ( this.attr( 'class' ) || '' ).split( ' ' );

    if ( currentKlasses === [ '' ] ) { return this; }

    for ( var i = 0, klass; klass = klasses[ i ++ ]; ) {
      ind = currentKlasses.indexOf( klass );
      if ( ind !== -1 ) { currentKlasses.splice( ind, 1 ); }
    }

    this.attr({ 'class': currentKlasses.join( ' ' ) });
    return this;
  };

});