HTML published from Tridion is typically created using Tridion Dreamweaver Templates (DWTs).  These templates can involve a lot of ‘If’ statements to check that values exist or what their value is etc.  I like to put line breaks between each DWT statement so that its easier to read and work with, which usually looks something like this (actually it can get a lot crazier than this!):

The only issue with doing this is that HTML white-space is preserved, resulting in tonnes of extra line breaks in the published HTML. I’m anal about HTML, (there will be NO extra line breaks, NOT ON MY WATCH!) so I wrote a little TBB to clean up any lines that are blank, here’s the code:

        public override void Transform(Engine engine, Package package)
        {
            this.Initialize(engine, package);

            //get output item from the package
            string outputName = Package.OutputName;
            Item outputItem = package.GetByName(outputName);

            // if the output is text based, lets clean it up
           if ((outputItem.Type == PackageItemType.String))
            {
                Logger.Debug("Output exists, cleaning empty lines");
                string uglyOutput = outputItem.GetAsString();

                //Gets the converted output string
                string fixedOutput = Regex.Replace(uglyOutput, @"^\s*$\n", string.Empty, RegexOptions.Multiline);
                //Remove the old output string, and put the new one in place
                Logger.Debug("Output cleaned, updating item in package");
                package.Remove(outputItem);
                outputItem.SetAsString(fixedOutput);
                package.PushItem(outputName, outputItem);
            }
        }


The usual caveat about the code published here is that it is using the SDL Tridion base classes