protected override string DoCompress(string source)
{
int totalLen = source.Length;
int startIndex = 0;
var comments = new ArrayList();
var preservedTokens = new ArrayList();
int max;
if (RemoveComments)
{
while ((startIndex = source.IndexOf(@"/*", startIndex, StringComparison.OrdinalIgnoreCase)) >= 0)
{
int endIndex = source.IndexOf(@"*/", startIndex + 2, StringComparison.OrdinalIgnoreCase);
if (endIndex < 0)
{
endIndex = totalLen;
}
// Note: java substring-length param = end index - 2 (which is end index - (startindex + 2))
string token = source.Substring(startIndex + 2, endIndex - (startIndex + 2));
comments.Add(token);
string newResult = Extensions.Replace(source, startIndex + 2, endIndex,
Tokens.PreserveCandidateComment + (comments.Count - 1) +
"___");
startIndex += 2;
source = newResult;
}
}
// Preserve strings so their content doesn't get accidently minified
var stringBuilder = new StringBuilder();
Match match = protectStringRegex.Match(source);
int index = 0;
while (match.Success)
{
var text = match.Groups[0].Value;
if (string.IsNullOrEmpty(text))
{
continue;
}
var token = match.Value;
var quote = token[0];
// Java code: token.substring(1, token.length() -1) .. but that's ...
// token.substring(start index, end index) .. while .NET it's length for the 2nd arg.
token = token.Substring(1, token.Length - 2);
// Maybe the string contains a comment-like substring?
// one, maybe more? put'em back then.
if (token.IndexOf(Tokens.PreserveCandidateComment, StringComparison.OrdinalIgnoreCase) >= 0)
{
max = comments.Count;
for (int i = 0; i < max; i += 1)
{
token = token.Replace(Tokens.PreserveCandidateComment + i + "___",
comments[i].ToString());
}
}
// Minify alpha opacity in filter strings.
token = Extensions.RegexReplace(token, "(?i)progid:DXImageTransform.Microsoft.Alpha\\(Opacity=",
"alpha(opacity=");
preservedTokens.Add(token);
string preserver = quote + Tokens.PreservedToken + (preservedTokens.Count - 1) + "___" +
quote;
index = Extensions.AppendReplacement(match, stringBuilder, source, preserver, index);
match = match.NextMatch();
}
Extensions.AppendTail(stringBuilder, source, index);
source = stringBuilder.ToString();
// Strings are safe, now wrestle the comments.
max = comments.Count;
for (int i = 0; i < max; i += 1)
{
var token = comments[i].ToString();
var placeholder = Tokens.PreserveCandidateComment + i + "___";
// ! in the first position of the comment means preserve
// so push to the preserved tokens while stripping the !
if (token.StartsWith("!"))
{
preservedTokens.Add(token);
source = source.Replace(placeholder, Tokens.PreservedToken + (preservedTokens.Count - 1) + "___");
continue;
}
// \ in the last position looks like hack for Mac/IE5
// shorten that to /*\*/ and the next one to /**/
if (token.EndsWith("\\"))
{
preservedTokens.Add("\\");
source = source.Replace(placeholder, Tokens.PreservedToken + (preservedTokens.Count - 1) + "___");
i = i + 1; // attn: advancing the loop.
preservedTokens.Add(string.Empty);
source = source.Replace(Tokens.PreserveCandidateComment + i + "___",
Tokens.PreservedToken + (preservedTokens.Count - 1) + "___");
continue;
}
// keep empty comments after child selectors (IE7 hack)
// e.g. html >/**/ body
if (token.Length == 0)
{
startIndex = source.IndexOf(placeholder, StringComparison.OrdinalIgnoreCase);
if (startIndex > 2)
{
if (source[startIndex - 3] == '>')
{
preservedTokens.Add(string.Empty);
source = source.Replace(placeholder,
Tokens.PreservedToken + (preservedTokens.Count - 1) + "___");
}
}
}
// In all other cases kill the comment.
// Is this a closed comment?
if (source.Contains("/*" + placeholder + "*/"))
{
source = source.Replace("/*" + placeholder + "*/", string.Empty);
}
else
{
// Nope - is it an unclosed comment?
if (source.Contains("/*" + placeholder))
{
// TODO: Add a Warning to the log (once we have a log!)
source = source.Replace("/*" + placeholder, string.Empty);
}
}
}
// Preserve any calc(...) css - https://yuicompressor.codeplex.com/workitem/11445
stringBuilder = new StringBuilder();
match = calcRegex.Match(source);
index = 0;
while (match.Success)
{
preservedTokens.Add(match.Value);
string preserver = Tokens.PreservedToken + (preservedTokens.Count - 1) + "___";
index = Extensions.AppendReplacement(match, stringBuilder, source, preserver, index);
match = match.NextMatch();
}
Extensions.AppendTail(stringBuilder, source, index);
source = stringBuilder.ToString();
// Normalize all whitespace strings to single spaces. Easier to work with that way.
source = Extensions.RegexReplace(source, "\\s+", " ");
// Remove the spaces before the things that should not have spaces before them.
// But, be careful not to turn "p :link {...}" into "p:link{...}"
// Swap out any pseudo-class colons with the token, and then swap back.
stringBuilder = new StringBuilder();
match = spaceRemoverRegex.Match(source);
index = 0;
while (match.Success)
{
string text = match.Value;
text = text.Replace(":", Tokens.PseudoClassColon);
text = text.Replace("\\\\", "\\\\\\\\");
text = text.Replace("\\$", "\\\\\\$");
index = Extensions.AppendReplacement(match, stringBuilder, source, text, index);
match = match.NextMatch();
}
Extensions.AppendTail(stringBuilder, source, index);
source = stringBuilder.ToString();
// Remove spaces before the things that should not have spaces before them.
source = Extensions.RegexReplace(source, "\\s+([!{};:>+\\(\\)\\],])", "$1");
// Bring back the colon.
source = Extensions.RegexReplace(source, Tokens.PseudoClassColon, ":");
// Retain space for special IE6 cases.
source = Extensions.RegexReplace(source, ":first\\-(line|letter)(\\{|,)", ":first-$1 $2");
// no space after the end of a preserved comment.
source = Extensions.RegexReplace(source, "\\*/ ", "*/");
// If there is a @charset, then only allow one, and push to the top of the file.
source = Extensions.RegexReplace(source, "^(.*)(@charset \"[^\"]*\";)", "$2$1");
source = Extensions.RegexReplace(source, "^(\\s*@charset [^;]+;\\s*)+", "$1");
// Put the space back in some cases, to support stuff like
// @media screen and (-webkit-min-device-pixel-ratio:0){
source = Extensions.RegexReplace(source, "\\band\\(", "and (");
// Remove the spaces after the things that should not have spaces after them.
source = Extensions.RegexReplace(source, "([!{}:;>+\\(\\[,])\\s+", "$1");
// remove unnecessary semicolons.
source = Extensions.RegexReplace(source, ";+}", "}");
// Replace 0(px,em,%) with 0.
source = Extensions.RegexReplace(source, "([\\s:])(0)(px|em|%|in|cm|mm|pc|pt|ex)", "$1$2");
// Replace 0 0 0 0; with 0.
source = Extensions.RegexReplace(source, ":0 0 0 0(;|})", ":0$1");
source = Extensions.RegexReplace(source, ":0 0 0(;|})", ":0$1");
source = Extensions.RegexReplace(source, ":0 0(;|})", ":0$1");
// Replace background-position:0; with background-position:0 0;
// same for transform-origin
stringBuilder = new StringBuilder();
match = backgroundPositionRegex.Match(source);
index = 0;
while (match.Success)
{
index = Extensions.AppendReplacement(match, stringBuilder, source,
match.Groups[1].Value.ToLowerInvariant() + ":0 0" + match.Groups[2],
index);
match = match.NextMatch();
}
Extensions.AppendTail(stringBuilder, source, index);
source = stringBuilder.ToString();
// Replace 0.6 to .6, but only when preceded by : or a white-space.
source = Extensions.RegexReplace(source, "(:|\\s)0+\\.(\\d+)", "$1.$2");
// Shorten colors from rgb(51,102,153) to #336699
// This makes it more likely that it'll get further compressed in the next step.
stringBuilder = new StringBuilder();
match = colorRegex.Match(source);
index = 0;
while (match.Success)
{
var rgbcolors = match.Groups[1].Value.Split(',');
var hexcolor = new StringBuilder("#");
foreach (var rgbColour in rgbcolors)
{
int value;
if (!Int32.TryParse(rgbColour, out value))
{
value = 0;
}
if (value < 16)
{
hexcolor.Append("0");
}
hexcolor.Append(Extensions.ToHexString(value).ToLowerInvariant());
}
index = Extensions.AppendReplacement(match, stringBuilder, source, hexcolor.ToString(), index);
match = match.NextMatch();
}
Extensions.AppendTail(stringBuilder, source, index);
source = stringBuilder.ToString();
// Shorten colors from #AABBCC to #ABC. Note that we want to make sure
// the color is not preceded by either ", " or =. Indeed, the property
// filter: chroma(color="#FFFFFF");
// would become
// filter: chroma(color="#FFF");
// which makes the filter break in IE.
stringBuilder = new StringBuilder();
match = colorShortenerRegex.Match(source);
index = 0;
while (match.Success)
{
// Test for AABBCC pattern.
if (Extensions.EqualsIgnoreCase(match.Groups[3].Value, match.Groups[4].Value) &&
Extensions.EqualsIgnoreCase(match.Groups[5].Value, match.Groups[6].Value) &&
Extensions.EqualsIgnoreCase(match.Groups[7].Value, match.Groups[8].Value))
{
string replacement = String.Concat(match.Groups[1].Value, match.Groups[2].Value, "#",
match.Groups[3].Value, match.Groups[5].Value,
match.Groups[7].Value);
index = Extensions.AppendReplacement(match, stringBuilder, source, replacement, index);
}
else
{
index = Extensions.AppendReplacement(match, stringBuilder, source, match.Value, index);
}
match = match.NextMatch();
}
Extensions.AppendTail(stringBuilder, source, index);
source = stringBuilder.ToString();
// border: none -> border:0
stringBuilder = new StringBuilder();
match = borderRegex.Match(source);
index = 0;
while (match.Success)
{
string replacement = match.Groups[1].Value.ToLowerInvariant() + ":0" + match.Groups[2].Value;
index = Extensions.AppendReplacement(match, stringBuilder, source, replacement, index);
match = match.NextMatch();
}
Extensions.AppendTail(stringBuilder, source, index);
source = stringBuilder.ToString();
// Shorter opacity IE filter.
source = Extensions.RegexReplace(source, "(?i)progid:DXImageTransform.Microsoft.Alpha\\(Opacity=", "alpha(opacity=");
// Remove empty rules.
if (source.Contains("{}"))
{
//Test if contains because this regex may be very time consuming, up until 1minute for some 150kb css!)
source = emptyRuleRegex.Replace(source, String.Empty);
}
if (LineBreakPosition >= 0)
{
// Some source control tools don't like it when files containing lines longer
// than, say 8000 characters, are checked in. The linebreak option is used in
// that case to split long lines after a specific column.
int i = 0;
int linestartpos = 0;
stringBuilder = new StringBuilder(source);
while (i < stringBuilder.Length)
{
char c = stringBuilder[i++];
if (c == '}' && i - linestartpos > LineBreakPosition)
{
stringBuilder.Insert(i, '\n');
linestartpos = i;
}
}
source = stringBuilder.ToString();
}
// Replace multiple semi-colons in a row by a single one.
// See SF bug #1980989.
source = Extensions.RegexReplace(source, ";;+", ";");
// Restore preserved comments and strings.
max = preservedTokens.Count;
for (int i = 0; i < max; i++)
{
source = source.Replace(Tokens.PreservedToken + i + "___", preservedTokens[i].ToString());
}
// Trim the final string (for any leading or trailing white spaces).
source = source.Trim();
// Write the output...
return(source);
}
