wro4j-core/src/main/java/ro/isdc/wro/model/resource/processor/decorator/ProcessorDecorator.java
private static ResourcePreProcessor toPreProcessor(final ResourcePostProcessor postProcessor) {
    return new AbstractProcessorDecoratorSupport<ResourcePostProcessor>(postProcessor) {
      public void process(final Resource resource, final Reader reader, final Writer writer)
          throws IOException {
        postProcessor.process(reader, writer);
      }

      @Override
      protected boolean isMinimizeInternal() {
        return isMinimizeForProcessor(postProcessor);
      }

      @Override
      protected SupportedResourceType getSupportedResourceTypeInternal() {
        return getSupportedResourceTypeForProcessor(postProcessor);
      }

      @Override
      public String toString() {
        return postProcessor.toString();
      }
    };
  }
private static ResourcePreProcessor toPreProcessor(final ResourcePostProcessor postProcessor) {
    return new AbstractProcessorDecoratorSupport<ResourcePostProcessor>(postProcessor) {
      public void process(final Resource resource, final Reader reader, final Writer writer)
          throws IOException {
        postProcessor.process(reader, writer);
      }

      @Override
      protected boolean isMinimizeInternal() {
        return isMinimizeForProcessor(postProcessor);
      }

      @Override
      protected SupportedResourceType getSupportedResourceTypeInternal() {
        return getSupportedResourceTypeForProcessor(postProcessor);
      }

      @Override
      public String toString() {
        return postProcessor.toString();
      }
    };
  }
Transforms a post processor into pre processor.