/// <summary>
/// Takes the content of a CSS file and the original absolute url of that
/// file, and changes all url() properties to absolute urls.
/// This way, if the CSS file has been combined with other files, the
/// images specified in the url() properties will still show.
/// </summary>
/// <param name="fileContent"></param>
/// <param name="fileUrl"></param>
private static void FixUrlProperties(
ref string fileContent, Uri fileUrl, UrlProcessor urlProcessor)
{
StringBuilder fileContentSb = new StringBuilder(fileContent);
const string regexpUrlProperty =
@"url\([\s\n\r]*(?<url>(?!http://)(?!https://)[^)]*?)[\s\n\r]*\)";
Regex r = new Regex(regexpUrlProperty, RegexOptions.IgnoreCase);
Match m = r.Match(fileContent);
// Visit each url property
while (m.Success)
{
string urlProperty = m.Value;
CaptureCollection urlProperties = m.Groups["url"].Captures;
if (urlProperties.Count > 0)
{
string relativeUrl = urlProperties[0].Value;
string absoluteUrl = urlProcessor.ProcessedUrl(relativeUrl, true, true, fileUrl, null);
fileContentSb.Replace(urlProperty, "url(" + absoluteUrl + ")");
}
m = m.NextMatch();
}
fileContent = fileContentSb.ToString();
}
private void ProcessAllImages (ControlCollection cc, UrlProcessor urlProcessor, bool removeWhitespace)
{
bool imagesNeedProcessing = urlProcessor.ImagesNeedProcessing ();
foreach (Control c in cc) {
if (c is LiteralControl) {
LiteralControl lit = (LiteralControl)c;
string literalContent = lit.Text;
string newLiteralContent = literalContent;
if (imagesNeedProcessing) {
// The "src" group in this regexp doesn't just contain the image url, but also the src= and the quotes.
// That allows us to replace the entire src="...", instead of the url.
// If you only replace the old url with the new url, than if you have a tag with url "images/ball3.png" after a tag with "/images/ball3.png"
// when the second url ("images/ball3.png") gets replaced, it alsos replace part of the first tag "/images/ball3.png" (because the first tag
// contains the second tag).
const string regexpImgGroup =
@"<img[^>]*?(?<src>src[^=]*?=[^""']*?(?:""|')(?<url>[^""']*?)(?:""|'))[^>]*?>";
Regex r = new Regex (regexpImgGroup, RegexOptions.IgnoreCase);
Match m = r.Match (literalContent);
while (m.Success) {
string oldSrc = m.Groups ["src"].Value;
string oldUrl = m.Groups ["url"].Value;
string newUrl = urlProcessor.ProcessedUrl (oldUrl, true, false, Control.Page.Request.Url, null);
string newSrc = @"src=""" + newUrl + @"""";
newLiteralContent = newLiteralContent.Replace (oldSrc, newSrc);
m = m.NextMatch ();
}
}
if (removeWhitespace) {
newLiteralContent = CollapsedWhitespace (newLiteralContent);
}
lit.Text = newLiteralContent;
} else if ((c is HtmlImage) && imagesNeedProcessing) {
HtmlImage hi = (HtmlImage)c;
string versionId = LastUpdateTimeImageControl (hi.Src, hi, urlProcessor.ThrowExceptionOnMissingFile);
hi.Src = urlProcessor.ProcessedUrl (hi.Src, true, false, Control.Page.Request.Url, versionId);
} else if ((c is HyperLink) && imagesNeedProcessing) {
HyperLink hl = (HyperLink)c;
string versionId = LastUpdateTimeImageControl (hl.ImageUrl, hl, urlProcessor.ThrowExceptionOnMissingFile);
hl.ImageUrl = urlProcessor.ProcessedUrl (hl.ImageUrl, true, false, Control.Page.Request.Url, versionId);
} else if ((c is Image) && imagesNeedProcessing) {
Image i = (Image)c;
string versionId = LastUpdateTimeImageControl (i.ImageUrl, i, urlProcessor.ThrowExceptionOnMissingFile);
i.ImageUrl = urlProcessor.ProcessedUrl (i.ImageUrl, true, false, Control.Page.Request.Url, versionId);
} else {
ProcessAllImages (c.Controls, urlProcessor, removeWhitespace);
}
}
}
/// <summary>
/// Returns a combined file url.
/// </summary>
/// <param name="urlsHash">
/// Hash based on the urls of the files that make up the combined file.
/// </param>
/// <param name="versionId">
/// A string that is different for each version of the files that make up
/// the combined file. This is used to make sure that a browser doesn't
/// pick up an outdated version from its internal browser cache.
/// </param>
/// <param name="fileType">
/// </param>
/// <param name="urlDomain">
/// Domain to be used for the url.
/// Make null or empty if you don't want a domain used in the url.
/// </param>
/// <returns></returns>
private static string CombinedFileUrl(
string urlsHash, string versionId, FileTypeUtilities.FileType fileType, UrlProcessor urlProcessor)
{
string url = "/" + urlsHash + FileTypeUtilities.FileTypeToExtension(fileType);
return urlProcessor.ProcessedUrl(url, false, false, null, versionId);
}
