private void RewriteStyleAttributes(ResponseAnalysisContext context, string html)
{
var headIndex = html.IndexOf("</head>", StringComparison.OrdinalIgnoreCase);
if (headIndex == -1)
{
return;
}
SortedList <string, StringSegment> inlineStyles = null;
foreach (var index in FastHtmlParser.FindAllAttributeIndexes(html, "style"))
{
// get content
var inner = FastHtmlParser.GetAttributeValueAtName(html, "style", index);
if (inner.Length == 0)
{
continue;
}
if (inlineStyles == null)
{
inlineStyles = new SortedList <string, StringSegment>();
}
// compute hash
var hash = ComputeHash(inner.Trim());
if (!inlineStyles.ContainsKey(hash))
{
inlineStyles.Add(hash, inner);
}
// add change
context.AddChange(TextChange.Remove(html, index, inner.Offset + inner.Length + 1 - index));
var tagIndex = FastHtmlParser.FindOpenTagAtAttribute(html, index);
var classAttribute = FastHtmlParser.GetAttributeValueAtTag(html, "class", tagIndex);
if (classAttribute.Length > 0)
{
context.AddChange(TextChange.Insert(html, classAttribute.Offset + classAttribute.Length, "_" + hash));
}
else
{
context.AddChange(FastHtmlParser.CreateInsertAttributeChange(html, tagIndex, "class", "_" + hash));
}
}
// assemble inline styles
if (inlineStyles != null && inlineStyles.Count > 0)
{
var hashBuilder = new InplaceStringBuilder(inlineStyles.Count * HashBytes * 2);
foreach (var entry in inlineStyles)
{
hashBuilder.Append(entry.Key);
}
var hash = ComputeHash(hashBuilder.ToString());
if (!InlineContentService.ContainsStyleByHash(hash))
{
var contentBuilder = StringBuilderPool.Get();
foreach (var entry in inlineStyles)
{
contentBuilder.Append('.');
contentBuilder.Append('_');
contentBuilder.Append(entry.Key);
contentBuilder.Append('{');
contentBuilder.Append(entry.Value.Value);
contentBuilder.Append('}');
}
InlineContentService.TryAddStyleByHash(hash, contentBuilder.ToString());
StringBuilderPool.Return(contentBuilder);
}
var tag = $"<link rel=\"stylesheet\" href=\"/.waf/styles/{hash}\" type=\"text/css\" />";
context.AddChange(TextChange.Insert(html, headIndex, tag));
}
}