/// <summary>
/// Corrects all relative image paths inside a style sheet to turn them into full paths
/// in order to allow for these style sheets to work when combined into one file.
/// Also, if 'rewriteImagePaths' is true, prepends a subdomain to all image paths in the css file.
/// </summary>
/// <param name="cssContent">The contents of the css file</param>
/// <param name="cssFilePath">The path of the css file</param>
/// <param name="rewriteImagePaths">If true will prepend a subdomain to all image paths in this css</param>
/// <param name="imagesHostToPrepend">The subdomain to prepend to the image paths</param>
/// <returns></returns>
private static string FixImagePaths(string cssContent, string cssFilePath, bool rewriteImagePaths, string imagesHostToPrepend)
{
var processedUrls = new Dictionary <string, string>();
var imgRgx = new Regex(@"(?<=url\().*?\)");
MatchCollection imgMatches = imgRgx.Matches(cssContent);
foreach (Match imgM in imgMatches)
{
string url = imgM.ToString().Replace(")", "").Replace("\"", "").Replace("'", "").Trim();
if (string.IsNullOrEmpty(url) || processedUrls.ContainsKey(url))
{
continue;
}
processedUrls.Add(url, url);
var rgxUsedToReplaceInCss = new Regex(@"\(\s*[""']{0,1}" + url + @"[""|']{0,1}\s*\)");
// correct the image path relative to the cssFilePath (if doesn't start with /cms)
string correctedImgPath = ImagePathsUtility.CorrectUrl(url, cssFilePath);
if (rewriteImagePaths && !ImagePathsUtility.IsFont(url))
{
// forward slash in the beginning not required here, since this will be an absolute path
correctedImgPath = string.Format("{0}/{1}", imagesHostToPrepend, correctedImgPath.TrimStart('/'));
}
cssContent = rgxUsedToReplaceInCss.Replace(cssContent, "(" + correctedImgPath + ")");
}
return(cssContent);
}
protected override void Process2(ref CombinerFilterContext data)
{
if (!data.PrependCdnHostToImages || string.IsNullOrEmpty(data.CdnHostToPrepend))
{
return;
}
if (Images == null)
{
return;
}
foreach (HtmlNode img in Images)
{
var url = img.Attributes["src"].Value;
if (string.IsNullOrEmpty(url) || url.StartsWith("http"))
{
continue;
}
// correct the image path relative to the requested page path (if doesn't start with /cms)
string correctedImgPath = ImagePathsUtility.CorrectUrl(url, data.RequestPath);
url = string.Format("{0}/{1}", data.CdnHostToPrepend, correctedImgPath.TrimStart('/'));
img.Attributes["src"].Value = url;
}
}