Sitecore 7,2-compatible rich text image dimension stripper

DimensionStrippingGetImageFieldValue.cs

// Strips width and height attributes from Sitecore field rendered images without messing with the 
// resizer's width and height attributes (as opposed to maxwidth/maxheight)
public class DimensionStrippingGetImageFieldValue : GetImageFieldValue
{
	protected override Sitecore.Xml.Xsl.ImageRenderer CreateRenderer()
	{
		return new ImageRenderer();
	}

	private class ImageRenderer : Sitecore.Xml.Xsl.ImageRenderer
	{
		public override RenderFieldResult Render()
		{
			var baseResult = base.Render();

			if (baseResult.IsEmpty) return baseResult;

			var imageHtml = baseResult.FirstPart;

			imageHtml = imageHtml.ReplaceRegex("(width|height)=\"([^']*?)\" ", string.Empty);

			return new RenderFieldResult(imageHtml);
		}
	}
}

StripRichTextImageFixedDimensions.cs

// Sitecore 7.2's rich text editor uses inline style attributes to set image width/height. This strips those style attributes.
public class StripRichTextImageFixedDimensions
{
	public void Process(RenderFieldArgs args)
	{
		if (args.FieldTypeKey == "rich text")
		{
			Profiler.StartOperation("Stripping image tag dimensions from field: " + args.FieldName);
			args.Result.FirstPart = StripDimensions(args.Result.FirstPart);
			Profiler.EndOperation();
		}
	}

	private static string StripDimensions(string text)
	{
		if (string.IsNullOrWhiteSpace(text))
		{
			return text;
		}

		string outText = text;
		try
		{
			var doc = new HtmlDocument();
			doc.LoadHtml(outText);

			StripImageStyleAttributes(doc, "width", "height");

			outText = doc.DocumentNode.WriteContentTo();
		}
		catch (Exception ex) { Log.Error("Error removing dimensions from HTML!", ex); }

		return outText;
	}

	private static void StripImageStyleAttributes(HtmlDocument doc, params string[] styleAttributes)
	{
		// For reasons surpassing all understanding, HtmeAgilityPack returns null instead of an empty collection
		// when the query finds no results.
		HtmlNodeCollection nodes = doc.DocumentNode.SelectNodes("//img[@style]");

		if (nodes == null || nodes.Count.Equals(0))
		{
			return;
		}

		foreach (HtmlNode node in nodes)
		{
			// find each style declaration and remove any attributes that match our kill-list
			var validStyles = node.GetAttributeValue("style", string.Empty).Split(';')
				.Select(x => x.Trim())
				.Where(x=>!styleAttributes.Contains(x.Split(':').First().Trim()));

			node.SetAttributeValue("style", string.Join(";", validStyles));
		}
	}
}