/// <summary>
/// Take the set of properties that serializes to a shorter string.
///
/// When (presumably equivalent) blocks of CSS are passed in, this method checks that certain attempts
/// at minification actually resulted in shorter strings.
///
/// This isn't always guaranteed when you're injecting default values.
/// </summary>
private static IEnumerable <NameValueProperty> TakeShorter(IEnumerable <NameValueProperty> first, IEnumerable <NameValueProperty> second)
{
Func <IEnumerable <NameValueProperty>, string> toString =
x =>
{
using (var writer = new StringWriter())
using (var css = new MinimalCssWriter(writer))
{
x.Each(e => css.WriteRule(e, false));
return(writer.ToString());
}
};
var map = new[] { Tuple.Create(first, toString(first)), Tuple.Create(second, toString(second)) };
return(map.OrderBy(o => o.Item2.Length).First().Item1);
}
public static List <Block> Task(List <Block> blocks)
{
var ret = new List <Block>();
ret.AddRange(blocks.OfType <CssCharset>());
ret.AddRange(blocks.OfType <Model.Import>().Select(s => new Model.Import(MinifyValue(s.ToImport), ForQuery(s.MediaQuery), s.Start, s.Stop, s.FilePath)));
ret.AddRange(blocks.Where(w => w is SelectorAndBlock && ((SelectorAndBlock)w).IsReset));
var remainder = blocks.Where(w => !ret.Contains(w));
foreach (var statement in remainder)
{
var block = statement as SelectorAndBlock;
if (block != null)
{
var rules = new List <Property>();
foreach (var prop in block.Properties)
{
rules.Add(MinifyProperty(prop));
}
rules = MinifyPropertyList(rules).ToList();
ret.Add(new SelectorAndBlock(block.Selector, rules, block.ResetContext, block.Start, block.Stop, block.FilePath));
continue;
}
var media = statement as MediaBlock;
if (media != null)
{
var subStatements = Task(media.Blocks.ToList());
ret.Add(new MediaBlock(ForQuery(media.MediaQuery), subStatements, media.Start, media.Stop, media.FilePath));
continue;
}
var keyframes = statement as KeyFramesBlock;
if (keyframes != null)
{
var frames = new List <KeyFrame>();
// minify each frame
foreach (var frame in keyframes.Frames)
{
var blockEquiv = new SelectorAndBlock(InvalidSelector.Singleton, frame.Properties, null, frame.Start, frame.Stop, frame.FilePath);
var mind = Task(new List <Block>()
{
blockEquiv
});
frames.Add(new KeyFrame(frame.Percentages.ToList(), ((SelectorAndBlock)mind[0]).Properties.ToList(), frame.Start, frame.Stop, frame.FilePath));
}
// collapse frames if rules are identical
var frameMap =
frames.ToDictionary(
d =>
{
using (var str = new StringWriter())
using (var css = new MinimalCssWriter(str))
{
foreach (var rule in d.Properties.Cast <NameValueProperty>())
{
css.WriteRule(rule, lastRule: false);
}
return(str.ToString());
}
},
d => d
);
frames.Clear();
foreach (var frame in frameMap.GroupBy(k => k.Key))
{
var allPercents = new List <decimal>();
foreach (var f in frame)
{
allPercents.AddRange(f.Value.Percentages);
}
var urFrame = frame.First().Value;
frames.Add(new KeyFrame(allPercents, urFrame.Properties.ToList(), urFrame.Start, urFrame.Stop, urFrame.FilePath));
}
ret.Add(new KeyFramesBlock(keyframes.Prefix, keyframes.Name, frames, keyframes.Variables.ToList(), keyframes.Start, keyframes.Stop, keyframes.FilePath));
continue;
}
ret.Add(statement);
}
return(ret);
}
public static List<Block> Task(List<Block> blocks)
{
var ret = new List<Block>();
ret.AddRange(blocks.OfType<CssCharset>());
ret.AddRange(blocks.OfType<Model.Import>().Select(s => new Model.Import(MinifyValue(s.ToImport), ForQuery(s.MediaQuery), s.Start, s.Stop, s.FilePath)));
ret.AddRange(blocks.Where(w => w is SelectorAndBlock && ((SelectorAndBlock)w).IsReset));
var remainder = blocks.Where(w => !ret.Contains(w));
foreach (var statement in remainder)
{
var block = statement as SelectorAndBlock;
if (block != null)
{
var rules = new List<Property>();
foreach (var prop in block.Properties)
{
rules.Add(MinifyProperty(prop));
}
rules = MinifyPropertyList(rules).ToList();
ret.Add(new SelectorAndBlock(block.Selector, rules, block.ResetContext, block.Start, block.Stop, block.FilePath));
continue;
}
var media = statement as MediaBlock;
if (media != null)
{
var subStatements = Task(media.Blocks.ToList());
ret.Add(new MediaBlock(ForQuery(media.MediaQuery), subStatements, media.Start, media.Stop, media.FilePath));
continue;
}
var keyframes = statement as KeyFramesBlock;
if (keyframes != null)
{
var frames = new List<KeyFrame>();
// minify each frame
foreach (var frame in keyframes.Frames)
{
var blockEquiv = new SelectorAndBlock(InvalidSelector.Singleton, frame.Properties, null, frame.Start, frame.Stop, frame.FilePath);
var mind = Task(new List<Block>() { blockEquiv });
frames.Add(new KeyFrame(frame.Percentages.ToList(), ((SelectorAndBlock)mind[0]).Properties.ToList(), frame.Start, frame.Stop, frame.FilePath));
}
// collapse frames if rules are identical
var frameMap =
frames.ToDictionary(
d =>
{
using (var str = new StringWriter())
using (var css = new MinimalCssWriter(str))
{
foreach (var rule in d.Properties.Cast<NameValueProperty>())
{
css.WriteRule(rule, lastRule: false);
}
return str.ToString();
}
},
d => d
);
frames.Clear();
foreach (var frame in frameMap.GroupBy(k => k.Key))
{
var allPercents = new List<decimal>();
foreach (var f in frame)
{
allPercents.AddRange(f.Value.Percentages);
}
var urFrame = frame.First().Value;
frames.Add(new KeyFrame(allPercents, urFrame.Properties.ToList(), urFrame.Start, urFrame.Stop, urFrame.FilePath));
}
ret.Add(new KeyFramesBlock(keyframes.Prefix, keyframes.Name, frames, keyframes.Variables.ToList(), keyframes.Start, keyframes.Stop, keyframes.FilePath));
continue;
}
ret.Add(statement);
}
return ret;
}