/// <summary>
/// Upgrades a META content-type tag to the META charset tag
/// </summary>
/// <param name="tag">META content-type tag</param>
/// <returns>META charset tag</returns>
private HtmlTag UpgradeToMetaCharsetTag(HtmlTag tag)
{
HtmlTag upgradedTag = tag;
HtmlAttribute contentAttribute = tag.Attributes.SingleOrDefault(a => a.Name == "content");
if (contentAttribute != null)
{
string content = contentAttribute.Value.Trim();
if (content.Length > 0)
{
Match contentMatch = _metaContentTypeTagValueRegex.Match(content);
if (contentMatch.Success)
{
string charset = contentMatch.Groups["charset"].Value;
upgradedTag = new HtmlTag(tag.Name,
new List<HtmlAttribute> {new HtmlAttribute("charset", charset, HtmlAttributeType.Text)},
tag.Flags);
}
}
}
return upgradedTag;
}
/// <summary>
/// Builds a string representation of the attribute
/// </summary>
/// <param name="context">Markup parsing context</param>
/// <param name="attribute">HTML attribute</param>
/// <param name="tag">HTML tag</param>
/// <returns>String representation of the attribute</returns>
private string BuildAttributeString(MarkupParsingContext context, HtmlTag tag, HtmlAttribute attribute)
{
string tagName = tag.Name;
HtmlTagFlags tagFlags = tag.Flags;
IList<HtmlAttribute> attributes = tag.Attributes;
string attributeString;
string attributeName = attribute.Name;
string attributeValue = attribute.Value;
bool attributeHasValue = attribute.HasValue;
HtmlAttributeType attributeType = attribute.Type;
bool useHtmlSyntax = !_settings.UseXhtmlSyntax;
if (useHtmlSyntax && IsXmlAttribute(attributeName))
{
string sourceCode = context.SourceCode;
SourceCodeNodeCoordinates attributeCoordinates = attribute.NameCoordinates;
WriteWarning(LogCategoryConstants.HtmlMinificationWarning,
string.Format(Strings.WarningMessage_XmlBasedAttributeNotAllowed, attributeName), _fileContext,
attributeCoordinates.LineNumber, attributeCoordinates.ColumnNumber,
SourceCodeNavigator.GetSourceFragment(sourceCode, attributeCoordinates));
}
if ((_settings.RemoveRedundantAttributes && IsAttributeRedundant(tagName, attributeName, attributeValue, attributes))
|| (_settings.RemoveJsTypeAttributes && IsJavaScriptTypeAttribute(tagName, attributeName, attributeValue))
|| (_settings.RemoveCssTypeAttributes && IsCssTypeAttribute(tagName, attributeName, attributeValue, attributes))
|| (useHtmlSyntax && CanRemoveXmlAttribute(tagName, attributeName)))
{
attributeString = string.Empty;
return attributeString;
}
bool isCustomBooleanAttribute = (!attributeHasValue && attributeType == HtmlAttributeType.Text);
if (isCustomBooleanAttribute && useHtmlSyntax)
{
attributeString = " " + attributeName;
return attributeString;
}
if (attributeType == HtmlAttributeType.Boolean)
{
if (_settings.CollapseBooleanAttributes)
{
attributeString = " " + attributeName;
return attributeString;
}
attributeValue = attributeName;
}
else if (isCustomBooleanAttribute)
{
attributeValue = string.Empty;
}
else
{
attributeValue = CleanAttributeValue(context, tag, attribute);
if (_settings.RemoveEmptyAttributes
&& CanRemoveEmptyAttribute(tagName, attributeName, attributeValue, attributeType))
{
attributeString = string.Empty;
return attributeString;
}
}
bool addQuotes = !CanRemoveAttributeQuotes(tagFlags, attributeValue, _settings.AttributeQuotesRemovalMode);
attributeString = InnerBuildAttributeString(attributeName, attributeValue, addQuotes);
return attributeString;
}
/// <summary>
/// Builds a attribute view model
/// </summary>
/// <param name="context">Markup parsing context</param>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>String representation of the attribute</returns>
private HtmlAttributeViewModel BuildAttributeViewModel(MarkupParsingContext context, HtmlTag tag, HtmlAttribute attribute)
{
string tagNameInLowercase = tag.NameInLowercase;
HtmlAttributeViewModel attributeViewModel;
string attributeName = attribute.Name;
string attributeNameInLowercase = attribute.NameInLowercase;
string attributeValue = attribute.Value;
bool attributeHasValue = attribute.HasValue;
bool attributeHasEmptyValue = !attributeHasValue || attributeValue.Length == 0;
HtmlAttributeType attributeType = attribute.Type;
bool useHtmlSyntax = !_settings.UseXhtmlSyntax;
if (useHtmlSyntax && attributeType == HtmlAttributeType.Xml && attributeNameInLowercase != "xmlns")
{
string sourceCode = context.SourceCode;
SourceCodeNodeCoordinates attributeCoordinates = attribute.NameCoordinates;
WriteWarning(LogCategoryConstants.HtmlMinificationWarning,
string.Format(Strings.WarningMessage_XmlBasedAttributeNotAllowed, attributeName), _fileContext,
attributeCoordinates.LineNumber, attributeCoordinates.ColumnNumber,
SourceCodeNavigator.GetSourceFragment(sourceCode, attributeCoordinates));
}
if ((_settings.RemoveRedundantAttributes && IsAttributeRedundant(tag, attribute))
|| (_settings.RemoveJsTypeAttributes && IsJavaScriptTypeAttribute(tag, attribute))
|| (_settings.RemoveCssTypeAttributes && IsCssTypeAttribute(tag, attribute))
|| (useHtmlSyntax && CanRemoveXmlNamespaceAttribute(tag, attribute)))
{
if (CanRemoveAttribute(tag, attribute))
{
attributeViewModel = HtmlAttributeViewModel.Empty;
return attributeViewModel;
}
}
bool isCustomBooleanAttribute = !attributeHasValue && attributeType == HtmlAttributeType.Text;
if (isCustomBooleanAttribute)
{
if (useHtmlSyntax)
{
attributeViewModel = InnerBuildAttributeViewModel(attribute, true, false);
return attributeViewModel;
}
attribute.Value = string.Empty;
}
else if (attributeType != HtmlAttributeType.Event
&& !attributeHasEmptyValue
&& TemplateTagHelpers.ContainsTag(attributeValue))
{
// Processing of template tags
StringBuilder attributeValueBuilder = StringBuilderPool.GetBuilder();
TemplateTagHelpers.ParseMarkup(attributeValue,
(localContext, expression, startDelimiter, endDelimiter) =>
{
string processedExpression = expression;
if (_settings.MinifyAngularBindingExpressions && startDelimiter == "{{" && endDelimiter == "}}")
{
processedExpression = MinifyAngularBindingExpression(context, attribute.ValueCoordinates,
localContext.NodeCoordinates, expression);
}
attributeValueBuilder.Append(startDelimiter);
attributeValueBuilder.Append(processedExpression);
attributeValueBuilder.Append(endDelimiter);
},
(localContext, textValue) =>
{
string processedTextValue = textValue;
if (attributeType == HtmlAttributeType.ClassName)
{
processedTextValue = Utils.CollapseWhitespace(textValue);
}
attributeValueBuilder.Append(processedTextValue);
}
);
string processedAttributeValue = attributeValueBuilder.ToString();
StringBuilderPool.ReleaseBuilder(attributeValueBuilder);
switch (attributeType)
{
case HtmlAttributeType.Uri:
case HtmlAttributeType.Numeric:
case HtmlAttributeType.ClassName:
processedAttributeValue = processedAttributeValue.Trim();
break;
case HtmlAttributeType.Style:
processedAttributeValue = processedAttributeValue.Trim();
processedAttributeValue = Utils.RemoveEndingSemicolon(processedAttributeValue);
break;
default:
if (_settings.MinifyAngularBindingExpressions && tag.Flags.HasFlag(HtmlTagFlags.Custom))
{
string elementDirectiveName = AngularHelpers.NormalizeDirectiveName(tagNameInLowercase);
if (elementDirectiveName == "ngPluralize" && attributeNameInLowercase == "when")
{
processedAttributeValue = MinifyAngularBindingExpression(context, attribute.ValueCoordinates,
processedAttributeValue);
}
}
break;
}
attribute.Value = processedAttributeValue;
}
else if (attributeType == HtmlAttributeType.Boolean)
{
if (_settings.CollapseBooleanAttributes)
{
attributeViewModel = InnerBuildAttributeViewModel(attribute, true, false);
return attributeViewModel;
}
attribute.Value = attributeName;
}
else
{
if (!attributeHasEmptyValue)
{
attribute.Value = CleanAttributeValue(context, tag, attribute);
}
if (_settings.RemoveEmptyAttributes && CanRemoveEmptyAttribute(tag, attribute))
{
if (CanRemoveAttribute(tag, attribute))
{
attributeViewModel = HtmlAttributeViewModel.Empty;
return attributeViewModel;
}
}
}
bool addQuotes = !CanRemoveAttributeQuotes(attribute, _settings.AttributeQuotesRemovalMode);
attributeViewModel = InnerBuildAttributeViewModel(attribute, false, addQuotes);
return attributeViewModel;
}
/// <summary>
/// Start tags handler
/// </summary>
/// <param name="context">Markup parsing context</param>
/// <param name="tag">HTML tag</param>
private void EndTagHandler(MarkupParsingContext context, HtmlTag tag)
{
HtmlNodeType previousNodeType = _currentNodeType;
string previousTagName;
IList<HtmlAttribute> previousTagAttributes;
if (_currentTag != null)
{
previousTagName = _currentTag.Name;
previousTagAttributes = _currentTag.Attributes;
}
else
{
previousTagName = string.Empty;
previousTagAttributes = new List<HtmlAttribute>();
}
string previousText = _currentText;
_currentNodeType = HtmlNodeType.EndTag;
_currentTag = tag;
_currentText = string.Empty;
string tagName = tag.Name;
HtmlTagFlags tagFlags = tag.Flags;
WhitespaceMinificationMode whitespaceMinificationMode = _settings.WhitespaceMinificationMode;
if (whitespaceMinificationMode != WhitespaceMinificationMode.None)
{
if (_tagsWithNotRemovableWhitespaceQueue.Count == 0 && !tagFlags.EmbeddedCode)
{
// Processing of whitespace, that followed before the end tag
bool allowTrimEnd = false;
if (tagFlags.Invisible)
{
allowTrimEnd = true;
}
else
{
if (whitespaceMinificationMode == WhitespaceMinificationMode.Medium)
{
allowTrimEnd = tagFlags.Block;
}
else if (whitespaceMinificationMode == WhitespaceMinificationMode.Aggressive)
{
allowTrimEnd = (tagFlags.Block || tagFlags.Inline || tagFlags.InlineBlock);
}
}
if (allowTrimEnd)
{
TrimEndLastBufferItem();
}
}
// Check if current tag is in a whitespace queue
if (_tagsWithNotRemovableWhitespaceQueue.Count > 0 && tagName == _tagsWithNotRemovableWhitespaceQueue.Last())
{
_tagsWithNotRemovableWhitespaceQueue.Dequeue();
}
}
if (_settings.RemoveOptionalEndTags
&& (previousNodeType == HtmlNodeType.EndTag
|| (previousTagName != tagName && string.IsNullOrWhiteSpace(previousText)))
&& !IsSafeOptionalEndTag(previousTagName))
{
if (CanRemoveOptionalTagByParentTagName(previousTagName, tagName))
{
RemoveLastEndTagFromBuffer(previousTagName);
}
}
bool isElementEmpty = (string.IsNullOrWhiteSpace(previousText) && previousTagName == tagName
&& previousNodeType != HtmlNodeType.EndTag);
if (_settings.RemoveTagsWithoutContent && isElementEmpty
&& CanRemoveTagWithoutContent(previousTagName, previousTagAttributes))
{
// Remove last "element" from buffer, return
if (RemoveLastStartTagFromBuffer(tagName))
{
FlushBuffer();
return;
}
}
if (_settings.RemoveOptionalEndTags && tagFlags.OptionalEndTag && IsSafeOptionalEndTag(tagName))
{
// Leave only start tag in buffer
FlushBuffer();
return;
}
// Add end tag to buffer
_buffer.Add("</");
_buffer.Add(tagName);
_buffer.Add(">");
}
/// <summary>
/// Checks whether the attribute is redundant
/// </summary>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>Result of check (true - is redundant; false - is not redundant)</returns>
private static bool IsAttributeRedundant(HtmlTag tag, HtmlAttribute attribute)
{
string tagNameInLowercase = tag.NameInLowercase;
IList<HtmlAttribute> attributes = tag.Attributes;
string attributeNameInLowercase = attribute.NameInLowercase;
string attributeValue = attribute.Value;
string processedAttributeValue = attributeValue.Trim();
return (
(tagNameInLowercase == "script"
&& ((attributeNameInLowercase == "language" && processedAttributeValue.IgnoreCaseEquals("javascript"))
|| (attributeNameInLowercase == "charset" && attributes.All(a => a.NameInLowercase != "src"))))
|| (tagNameInLowercase == "link" && attributeNameInLowercase == "charset" && attributes.Any(
a => a.NameInLowercase == "rel" && a.Value.Trim().IgnoreCaseEquals("stylesheet")))
|| (tagNameInLowercase == "form" && attributeNameInLowercase == "method"
&& processedAttributeValue.IgnoreCaseEquals("get"))
|| (tagNameInLowercase == "input" && attributeNameInLowercase == "type"
&& processedAttributeValue.IgnoreCaseEquals("text"))
|| (tagNameInLowercase == "a" && attributeNameInLowercase == "name" && attributes.Any(
a => a.NameInLowercase == "id" && a.Value == attributeValue))
|| (tagNameInLowercase == "area" && attributeNameInLowercase == "shape"
&& processedAttributeValue.IgnoreCaseEquals("rect"))
);
}
/// <summary>
/// Checks whether attribute is the attribute <code>type</code> of
/// tag <code>script</code>, that containing JavaScript code
/// </summary>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>Result of check</returns>
private static bool IsJavaScriptTypeAttribute(HtmlTag tag, HtmlAttribute attribute)
{
return tag.NameInLowercase == "script" && attribute.NameInLowercase == "type"
&& attribute.Value.Trim().IgnoreCaseEquals(JS_CONTENT_TYPE);
}
/// <summary>
/// Removes a last end tag from the HTML minification buffer
/// </summary>
/// <param name="endTag">End tag</param>
private void RemoveLastEndTagFromBuffer(HtmlTag endTag)
{
int bufferItemCount = _buffer.Count;
if (bufferItemCount == 0)
{
return;
}
int lastEndTagBeginAngleBracketIndex = _buffer.LastIndexOf("</");
if (lastEndTagBeginAngleBracketIndex != -1)
{
string lastEndTagName = _buffer[lastEndTagBeginAngleBracketIndex + 1];
if (lastEndTagName.IgnoreCaseEquals(endTag.NameInLowercase))
{
int lastEndTagEndAngleBracketIndex = _buffer.IndexOf(">", lastEndTagBeginAngleBracketIndex);
if (lastEndTagEndAngleBracketIndex != -1)
{
int lastBufferItemIndex = bufferItemCount - 1;
bool noMoreContent = true;
if (lastEndTagEndAngleBracketIndex != lastBufferItemIndex)
{
for (int bufferItemIndex = lastEndTagEndAngleBracketIndex + 1;
bufferItemIndex < bufferItemCount;
bufferItemIndex++)
{
if (!string.IsNullOrWhiteSpace(_buffer[bufferItemIndex]))
{
noMoreContent = false;
break;
}
}
}
if (noMoreContent)
{
int endTagLength = lastEndTagEndAngleBracketIndex - lastEndTagBeginAngleBracketIndex + 1;
_buffer.RemoveRange(lastEndTagBeginAngleBracketIndex, endTagLength);
}
}
}
}
}
/// <summary>
/// Checks whether remove whitespace between non-independent tags
/// </summary>
/// <param name="firstTag">First tag</param>
/// <param name="secondTag">Second tag</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private static bool CanRemoveWhitespaceBetweenNonIndependentTags(HtmlTag firstTag, HtmlTag secondTag)
{
string firstTagNameInLowercase = firstTag.NameInLowercase;
string secondTagNameInLowercase = secondTag.NameInLowercase;
bool cannotRemove;
switch (firstTagNameInLowercase)
{
case "li":
cannotRemove = secondTagNameInLowercase == "li";
break;
case "dt":
case "dd":
cannotRemove = secondTagNameInLowercase == "dt" || secondTagNameInLowercase == "dd";
break;
case "img":
cannotRemove = secondTagNameInLowercase == "figcaption";
break;
default:
cannotRemove = secondTagNameInLowercase == "rt" || secondTagNameInLowercase == "rp"
|| secondTagNameInLowercase == "rb" || secondTagNameInLowercase == "rtc";
break;
}
return !cannotRemove;
}
/// <summary>
/// Checks whether remove an the safe optional end tag
/// </summary>
/// <param name="optionalEndTag">Optional end tag</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private bool CanRemoveSafeOptionalEndTag(HtmlTag optionalEndTag)
{
string optionalEndTagNameInLowercase = optionalEndTag.NameInLowercase;
if (_settings.PreservableOptionalTagCollection.Contains(optionalEndTagNameInLowercase))
{
return false;
}
return _safeOptionalEndTags.Contains(optionalEndTagNameInLowercase);
}
/// <summary>
/// Cleans a attribute value
/// </summary>
/// <param name="context">Markup parsing context</param>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>Processed attribute value</returns>
private string CleanAttributeValue(MarkupParsingContext context, HtmlTag tag, HtmlAttribute attribute)
{
string attributeValue = attribute.Value;
if (attributeValue.Length == 0)
{
return attributeValue;
}
string processedAttributeValue = attributeValue;
string tagNameInLowercase = tag.NameInLowercase;
IList<HtmlAttribute> attributes = tag.Attributes;
string attributeNameInLowercase = attribute.NameInLowercase;
HtmlAttributeType attributeType = attribute.Type;
switch (attributeType)
{
case HtmlAttributeType.Uri:
processedAttributeValue = processedAttributeValue.Trim();
if (processedAttributeValue.StartsWith(HTTP_PROTOCOL, StringComparison.OrdinalIgnoreCase))
{
if (_settings.RemoveHttpProtocolFromAttributes && !ContainsRelExternalAttribute(attributes))
{
int httpProtocolLength = HTTP_PROTOCOL.Length;
processedAttributeValue = processedAttributeValue.Substring(httpProtocolLength);
}
}
else if (processedAttributeValue.StartsWith(HTTPS_PROTOCOL, StringComparison.OrdinalIgnoreCase))
{
if (_settings.RemoveHttpsProtocolFromAttributes && !ContainsRelExternalAttribute(attributes))
{
int httpsProtocolLength = HTTPS_PROTOCOL.Length;
processedAttributeValue = processedAttributeValue.Substring(httpsProtocolLength);
}
}
else if (attributeNameInLowercase == "href"
&& processedAttributeValue.StartsWith(JS_PROTOCOL, StringComparison.OrdinalIgnoreCase))
{
processedAttributeValue = ProcessInlineScriptContent(context, attribute);
}
break;
case HtmlAttributeType.Numeric:
processedAttributeValue = processedAttributeValue.Trim();
break;
case HtmlAttributeType.ClassName:
if (AngularHelpers.IsClassDirective(processedAttributeValue))
{
// Processing of Angular class directives
string ngOriginalDirectiveName = string.Empty;
string ngNormalizedDirectiveName = string.Empty;
string ngExpression;
var ngDirectives = new Dictionary<string, string>();
AngularHelpers.ParseClassDirective(processedAttributeValue,
(localContext, originalDirectiveName, normalizedDirectiveName) =>
{
ngOriginalDirectiveName = originalDirectiveName;
ngNormalizedDirectiveName = normalizedDirectiveName;
ngExpression = null;
ngDirectives.Add(ngOriginalDirectiveName, ngExpression);
},
(localContext, expression) =>
{
ngExpression = expression;
if (_settings.MinifyAngularBindingExpressions
&& ContainsAngularBindingExpression(ngNormalizedDirectiveName))
{
ngExpression = MinifyAngularBindingExpression(context,
attribute.ValueCoordinates, localContext.NodeCoordinates,
expression);
}
ngDirectives[ngOriginalDirectiveName] = ngExpression;
},
localContext =>
{
if (ngDirectives[ngOriginalDirectiveName] == null)
{
ngDirectives[ngOriginalDirectiveName] = string.Empty;
}
}
);
int directiveCount = ngDirectives.Count;
if (directiveCount > 0)
{
StringBuilder directiveBuilder = StringBuilderPool.GetBuilder();
int directiveIndex = 0;
int lastDirectiveIndex = directiveCount - 1;
string previousExpression = null;
foreach (var directive in ngDirectives)
{
string directiveName = directive.Key;
string expression = directive.Value;
if (directiveIndex > 0 && (expression == null || previousExpression == null))
{
directiveBuilder.Append(" ");
}
directiveBuilder.Append(directiveName);
if (!string.IsNullOrWhiteSpace(expression))
{
directiveBuilder.AppendFormat(":{0}", expression);
}
if (directiveIndex < lastDirectiveIndex && expression != null)
{
directiveBuilder.Append(";");
}
previousExpression = expression;
directiveIndex++;
}
processedAttributeValue = directiveBuilder.ToString();
StringBuilderPool.ReleaseBuilder(directiveBuilder);
}
else
{
processedAttributeValue = string.Empty;
}
}
else
{
processedAttributeValue = processedAttributeValue.Trim();
processedAttributeValue = Utils.CollapseWhitespace(processedAttributeValue);
}
break;
case HtmlAttributeType.Style:
processedAttributeValue = ProcessInlineStyleContent(context, attribute);
break;
case HtmlAttributeType.Event:
processedAttributeValue = ProcessInlineScriptContent(context, attribute);
break;
default:
if (attributeNameInLowercase == "data-bind" && _settings.MinifyKnockoutBindingExpressions)
{
processedAttributeValue = MinifyKnockoutBindingExpression(context, attribute);
}
else if (tagNameInLowercase == "meta" && attributeNameInLowercase == "content"
&& attributes.Any(a => a.NameInLowercase == "name" && a.Value.Trim().IgnoreCaseEquals("keywords")))
{
processedAttributeValue = processedAttributeValue.Trim();
processedAttributeValue = Utils.CollapseWhitespace(processedAttributeValue);
processedAttributeValue = _separatingCommaWithSpacesRegex.Replace(processedAttributeValue, ",");
processedAttributeValue = _endingCommaWithSpacesRegex.Replace(processedAttributeValue, string.Empty);
}
else
{
if (_settings.MinifyAngularBindingExpressions
&& CanMinifyAngularBindingExpressionInAttribute(tag, attribute))
{
processedAttributeValue = MinifyAngularBindingExpression(context, attribute.ValueCoordinates,
processedAttributeValue);
}
}
break;
}
return processedAttributeValue;
}
/// <summary>
/// Checks whether remove an the optional end tag
/// </summary>
/// <param name="optionalEndTag">Optional end tag</param>
/// <param name="parentTag">Parent tag</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private bool CanRemoveOptionalEndTagByParentTag(HtmlTag optionalEndTag, HtmlTag parentTag)
{
string optionalEndTagNameInLowercase = optionalEndTag.NameInLowercase;
if (_settings.PreservableOptionalTagCollection.Contains(optionalEndTagNameInLowercase))
{
return false;
}
string parentTagNameInLowercase = parentTag.NameInLowercase;
bool canRemove;
switch (optionalEndTagNameInLowercase)
{
case "p":
canRemove = parentTagNameInLowercase != "a";
break;
case "li":
canRemove = parentTagNameInLowercase == "ul" || parentTagNameInLowercase == "ol"
|| parentTagNameInLowercase == "menu";
break;
case "tbody":
case "tfoot":
canRemove = parentTagNameInLowercase == "table";
break;
case "tr":
canRemove = parentTagNameInLowercase == "table" || parentTagNameInLowercase == "thead"
|| parentTagNameInLowercase == "tbody" || parentTagNameInLowercase == "tfoot";
break;
case "td":
case "th":
canRemove = parentTagNameInLowercase == "tr";
break;
case "option":
canRemove = parentTagNameInLowercase == "select" || parentTagNameInLowercase == "optgroup"
|| parentTagNameInLowercase == "datalist";
break;
case "optgroup":
canRemove = parentTagNameInLowercase == "select";
break;
case "dd":
canRemove = parentTagNameInLowercase == "dl";
break;
case "rt":
canRemove = parentTagNameInLowercase == "ruby" || parentTagNameInLowercase == "rtc";
break;
case "rp":
case "rb":
case "rtc":
canRemove = parentTagNameInLowercase == "ruby";
break;
default:
canRemove = false;
break;
}
return canRemove;
}
/// <summary>
/// Checks whether remove an the optional end tag
/// </summary>
/// <param name="optionalEndTag">Optional end tag</param>
/// <param name="nextTag">Next tag</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private bool CanRemoveOptionalEndTagByNextTag(HtmlTag optionalEndTag, HtmlTag nextTag)
{
string optionalEndTagNameInLowercase = optionalEndTag.NameInLowercase;
if (_settings.PreservableOptionalTagCollection.Contains(optionalEndTagNameInLowercase))
{
return false;
}
string nextTagNameInLowercase = nextTag.NameInLowercase;
bool canRemove;
switch (optionalEndTagNameInLowercase)
{
case "p":
canRemove = _tagsFollowingAfterParagraphOptionalEndTag.Contains(nextTagNameInLowercase);
break;
case "li":
canRemove = nextTagNameInLowercase == "li";
break;
case "thead":
case "tbody":
canRemove = nextTagNameInLowercase == "tbody" || nextTagNameInLowercase == "tfoot";
break;
case "tfoot":
canRemove = nextTagNameInLowercase == "tbody";
break;
case "tr":
canRemove = nextTagNameInLowercase == "tr";
break;
case "td":
case "th":
canRemove = nextTagNameInLowercase == "td" || nextTagNameInLowercase == "th";
break;
case "option":
canRemove = nextTagNameInLowercase == "option" || nextTagNameInLowercase == "optgroup";
break;
case "optgroup":
canRemove = nextTagNameInLowercase == "optgroup";
break;
case "dt":
case "dd":
canRemove = nextTagNameInLowercase == "dt" || nextTagNameInLowercase == "dd";
break;
case "rt":
case "rp":
case "rb":
canRemove = nextTagNameInLowercase == "rt" || nextTagNameInLowercase == "rp"
|| nextTagNameInLowercase == "rb" || nextTagNameInLowercase == "rtc"
;
break;
case "rtc":
canRemove = nextTagNameInLowercase == "rp" || nextTagNameInLowercase == "rb"
|| nextTagNameInLowercase == "rtc"
;
break;
default:
canRemove = false;
break;
}
return canRemove;
}
/// <summary>
/// Parses a end tag
/// </summary>
/// <param name="tagName">Tag name</param>
/// <param name="tagNameInLowercase">Tag name in lowercase</param>
private void ParseEndTag(string tagName, string tagNameInLowercase)
{
int endTagIndex = 0;
int lastTagIndex = _tagStack.Count - 1;
bool tagNameNotEmpty = !string.IsNullOrEmpty(tagName);
HtmlParsingHandlers.EndTagDelegate endTagHandler = _handlers.EndTag;
if (tagNameNotEmpty)
{
for (endTagIndex = lastTagIndex; endTagIndex >= 0; endTagIndex--)
{
if (_tagStack[endTagIndex].NameInLowercase == tagNameInLowercase)
{
break;
}
}
}
if (endTagIndex >= 0)
{
// Close all the open elements, up the stack
if (endTagHandler != null)
{
for (int tagIndex = lastTagIndex; tagIndex >= endTagIndex; tagIndex--)
{
HtmlTag startTag = _tagStack[tagIndex];
string startTagNameInLowercase = startTag.NameInLowercase;
HtmlTagFlags startTagFlags = startTag.Flags;
string endTagName;
if (tagNameNotEmpty && tagNameInLowercase == startTagNameInLowercase)
{
endTagName = tagName;
}
else
{
endTagName = startTag.Name;
}
if (_xmlTagStack.Count > 0 && !startTagFlags.IsSet(HtmlTagFlags.NonIndependent))
{
_xmlTagStack.Pop();
}
var endTag = new HtmlTag(endTagName, startTagNameInLowercase, startTagFlags);
endTagHandler(_context, endTag);
}
}
// Remove the open elements from the stack
if (endTagIndex <= lastTagIndex)
{
int tagToRemoveStartIndex = endTagIndex;
int tagsToRemoveCount = lastTagIndex - endTagIndex + 1;
_tagStack.RemoveRange(tagToRemoveStartIndex, tagsToRemoveCount);
}
}
else if (tagNameNotEmpty && _conditionalCommentOpened)
{
if (_xmlTagStack.Count > 0 && _tagTypeDeterminer.IsXmlBasedTag(tagNameInLowercase))
{
_xmlTagStack.Pop();
}
var endTag = new HtmlTag(tagName, tagNameInLowercase, GetTagFlagsByName(tagNameInLowercase));
endTagHandler?.Invoke(_context, endTag);
}
}
/// <summary>
/// Parses a end tag
/// </summary>
/// <param name="tagName">Tag name</param>
/// <param name="tagNameInLowercase">Tag name in lowercase</param>
private void ParseEndTag(string tagName, string tagNameInLowercase)
{
int endTagIndex = 0;
int lastTagIndex = _tagStack.Count - 1;
bool tagNameNotEmpty = !string.IsNullOrEmpty(tagName);
HtmlParsingHandlers.EndTagDelegate endTagHandler = _handlers.EndTag;
if (tagNameNotEmpty)
{
for (endTagIndex = lastTagIndex; endTagIndex >= 0; endTagIndex--)
{
if (_tagStack[endTagIndex].NameInLowercase == tagNameInLowercase)
{
break;
}
}
}
if (endTagIndex >= 0)
{
// Close all the open elements, up the stack
if (endTagHandler != null)
{
for (int tagIndex = lastTagIndex; tagIndex >= endTagIndex; tagIndex--)
{
HtmlTag startTag = _tagStack[tagIndex];
string startTagNameInLowercase = startTag.NameInLowercase;
HtmlTagFlags startTagFlags = startTag.Flags;
string endTagName;
if (tagNameNotEmpty && tagNameInLowercase == startTagNameInLowercase)
{
endTagName = tagName;
}
else
{
endTagName = startTag.Name;
}
if (_xmlTagStack.Count > 0 && !startTagFlags.HasFlag(HtmlTagFlags.NonIndependent))
{
_xmlTagStack.Pop();
}
var endTag = new HtmlTag(endTagName, startTagNameInLowercase, startTagFlags);
endTagHandler(_context, endTag);
}
}
// Remove the open elements from the stack
if (endTagIndex <= lastTagIndex)
{
int tagToRemoveStartIndex = endTagIndex;
int tagsToRemoveCount = lastTagIndex - endTagIndex + 1;
_tagStack.RemoveRange(tagToRemoveStartIndex, tagsToRemoveCount);
}
}
else if (tagNameNotEmpty && _conditionalCommentOpened)
{
if (_xmlTagStack.Count > 0 && HtmlTagFlagsHelpers.IsXmlBasedTag(tagNameInLowercase))
{
_xmlTagStack.Pop();
}
var endTag = new HtmlTag(tagName, tagNameInLowercase, GetTagFlagsByName(tagNameInLowercase));
if (endTagHandler != null)
{
endTagHandler(_context, endTag);
}
}
}
/// <summary>
/// Removes a last start tag from the HTML minification buffer
/// </summary>
/// <param name="startTag">Start tag</param>
/// <returns>Result of removing (true - has removed; false - has not removed)</returns>
private bool RemoveLastStartTagFromBuffer(HtmlTag startTag)
{
int bufferItemCount = _buffer.Count;
if (bufferItemCount == 0)
{
return false;
}
bool isEndTagRemoved = false;
int lastStartTagBeginAngleBracketIndex = _buffer.LastIndexOf("<");
if (lastStartTagBeginAngleBracketIndex != -1)
{
string lastTagName = _buffer[lastStartTagBeginAngleBracketIndex + 1];
if (lastTagName.IgnoreCaseEquals(startTag.NameInLowercase))
{
int lastStartTagEndAngleBracketIndex = _buffer.IndexOf(">", lastStartTagBeginAngleBracketIndex);
if (lastStartTagEndAngleBracketIndex != -1)
{
int lastBufferItemIndex = bufferItemCount - 1;
bool noMoreContent = true;
if (lastStartTagEndAngleBracketIndex != lastBufferItemIndex)
{
for (int bufferItemIndex = lastStartTagEndAngleBracketIndex + 1;
bufferItemIndex < bufferItemCount;
bufferItemIndex++)
{
if (!string.IsNullOrWhiteSpace(_buffer[bufferItemIndex]))
{
noMoreContent = false;
break;
}
}
}
if (noMoreContent)
{
_buffer.RemoveRange(lastStartTagBeginAngleBracketIndex,
bufferItemCount - lastStartTagBeginAngleBracketIndex);
isEndTagRemoved = true;
}
}
}
}
return isEndTagRemoved;
}
/// <summary>
/// Parses a start tag
/// </summary>
/// <param name="tagName">Tag name</param>
/// <param name="tagNameInLowercase">Tag name in lowercase</param>
/// <param name="attributes">List of attributes</param>
/// <param name="isEmptyTag">Flag that tag is empty</param>
private void ParseStartTag(string tagName, string tagNameInLowercase, List <HtmlAttribute> attributes,
bool isEmptyTag)
{
HtmlTagFlags tagFlags = GetTagFlagsByName(tagNameInLowercase);
if (tagFlags.IsSet(HtmlTagFlags.Optional))
{
HtmlTag lastStackedTag = _tagStack.LastOrDefault();
if (lastStackedTag != null && lastStackedTag.NameInLowercase == tagNameInLowercase)
{
ParseEndTag(lastStackedTag.Name, lastStackedTag.NameInLowercase);
}
else
{
if (tagNameInLowercase == "body" && _tagStack.Any(t => t.NameInLowercase == "head"))
{
HtmlTag headTag = _tagStack.First(t => t.NameInLowercase == "head");
ParseEndTag(headTag.Name, headTag.NameInLowercase);
}
}
}
if (tagFlags.IsSet(HtmlTagFlags.Empty))
{
isEmptyTag = true;
}
else if (isEmptyTag)
{
tagFlags |= HtmlTagFlags.Empty;
}
int attributeCount = attributes.Count;
for (int attributeIndex = 0; attributeIndex < attributeCount; attributeIndex++)
{
HtmlAttribute attribute = attributes[attributeIndex];
attribute.Type = _attributeTypeDeterminer.GetAttributeType(tagNameInLowercase, tagFlags,
attribute.NameInLowercase, attributes);
}
var tag = new HtmlTag(tagName, tagNameInLowercase, attributes, tagFlags);
if (!isEmptyTag)
{
if (_conditionalCommentOpened)
{
HtmlConditionalComment lastConditionalComment = _conditionalCommentStack.Peek();
HtmlConditionalCommentType lastConditionalCommentType = lastConditionalComment.Type;
if (tagFlags.IsSet(HtmlTagFlags.EmbeddedCode) ||
lastConditionalCommentType == HtmlConditionalCommentType.RevealedValidating ||
lastConditionalCommentType == HtmlConditionalCommentType.RevealedValidatingSimplified)
{
_tagStack.Add(tag);
}
}
else
{
_tagStack.Add(tag);
}
}
_handlers.StartTag?.Invoke(_context, tag);
if (tagFlags.IsSet(HtmlTagFlags.Xml) && !tagFlags.IsSet(HtmlTagFlags.NonIndependent))
{
_xmlTagStack.Push(tagNameInLowercase);
}
}
/// <summary>
/// Start tags handler
/// </summary>
/// <param name="context">Markup parsing context</param>
/// <param name="tag">HTML tag</param>
private void StartTagHandler(MarkupParsingContext context, HtmlTag tag)
{
HtmlNodeType previousNodeType = _currentNodeType;
HtmlTag previousTag = _currentTag ?? HtmlTag.Empty;
if (_settings.UseMetaCharsetTag && IsMetaContentTypeTag(tag))
{
tag = UpgradeToMetaCharsetTag(tag);
}
string tagName = tag.Name;
string tagNameInLowercase = tag.NameInLowercase;
HtmlTagFlags tagFlags = tag.Flags;
IList<HtmlAttribute> attributes = tag.Attributes;
_currentNodeType = HtmlNodeType.StartTag;
_currentTag = tag;
_currentText = string.Empty;
// Set whitespace flags for nested tags (for example <span> within a <pre>)
WhitespaceMinificationMode whitespaceMinificationMode = _settings.WhitespaceMinificationMode;
if (whitespaceMinificationMode != WhitespaceMinificationMode.None)
{
if (_tagsWithNotRemovableWhitespaceQueue.Count == 0)
{
// Processing of whitespace, that followed before the start tag
bool allowTrimEnd = false;
if (tagFlags.HasFlag(HtmlTagFlags.Invisible)
|| (tagFlags.HasFlag(HtmlTagFlags.NonIndependent)
&& CanRemoveWhitespaceBetweenNonIndependentTags(previousTag, tag)))
{
allowTrimEnd = true;
}
else
{
if (whitespaceMinificationMode == WhitespaceMinificationMode.Medium
|| whitespaceMinificationMode == WhitespaceMinificationMode.Aggressive)
{
allowTrimEnd = tagFlags.HasFlag(HtmlTagFlags.Block);
}
}
if (allowTrimEnd)
{
TrimEndLastBufferItem();
}
}
if (!CanMinifyWhitespace(tag))
{
_tagsWithNotRemovableWhitespaceQueue.Enqueue(tagNameInLowercase);
}
}
if (previousNodeType != HtmlNodeType.StartTag)
{
if (_settings.RemoveOptionalEndTags
&& previousTag.Flags.HasFlag(HtmlTagFlags.Optional)
&& CanRemoveOptionalEndTagByNextTag(previousTag, tag))
{
RemoveLastEndTagFromBuffer(previousTag);
}
FlushBuffer();
}
_buffer.Add("<");
_buffer.Add(CanPreserveCase() ? tagName : tagNameInLowercase);
int attributeCount = attributes.Count;
bool unsafeLastAttribute = false;
if (attributeCount > 0)
{
for (int attributeIndex = 0; attributeIndex < attributeCount; attributeIndex++)
{
HtmlAttributeViewModel attributeViewModel = BuildAttributeViewModel(context, tag, attributes[attributeIndex]);
if (!attributeViewModel.IsEmpty)
{
_buffer.Add(" ");
_buffer.Add(attributeViewModel.Name);
if (attributeViewModel.HasValue)
{
_buffer.Add("=");
if (attributeViewModel.HasQuotes)
{
_buffer.Add("\"");
}
_buffer.Add(attributeViewModel.Value);
if (attributeViewModel.HasQuotes)
{
_buffer.Add("\"");
}
}
unsafeLastAttribute = attributeViewModel.HasValue && !attributeViewModel.HasQuotes;
}
}
}
if (tagFlags.HasFlag(HtmlTagFlags.Empty))
{
HtmlEmptyTagRenderMode emptyTagRenderMode = _settings.EmptyTagRenderMode;
if (emptyTagRenderMode == HtmlEmptyTagRenderMode.NoSlash && tagFlags.HasFlag(HtmlTagFlags.Xml))
{
emptyTagRenderMode = HtmlEmptyTagRenderMode.SpaceAndSlash;
}
if (emptyTagRenderMode == HtmlEmptyTagRenderMode.Slash && unsafeLastAttribute)
{
emptyTagRenderMode = HtmlEmptyTagRenderMode.SpaceAndSlash;
}
if (emptyTagRenderMode == HtmlEmptyTagRenderMode.Slash)
{
_buffer.Add("/");
}
else if (emptyTagRenderMode == HtmlEmptyTagRenderMode.SpaceAndSlash)
{
_buffer.Add(" /");
}
}
_buffer.Add(">");
}
/// <summary>
/// Checks whether remove an the <code>xmlns</code> attribute
/// </summary>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private static bool CanRemoveXmlNamespaceAttribute(HtmlTag tag, HtmlAttribute attribute)
{
return tag.NameInLowercase == "html" && attribute.NameInLowercase == "xmlns";
}
/// <summary>
/// Constructs instance of generic HTML minifier
/// </summary>
/// <param name="settings">Generic HTML minification settings</param>
/// <param name="cssMinifier">CSS minifier</param>
/// <param name="jsMinifier">JS minifier</param>
/// <param name="logger">Logger</param>
public GenericHtmlMinifier(GenericHtmlMinificationSettings settings = null,
ICssMinifier cssMinifier = null, IJsMinifier jsMinifier = null, ILogger logger = null)
{
_settings = settings ?? new GenericHtmlMinificationSettings();
_logger = logger ?? new NullLogger();
_cssMinifier = cssMinifier ?? new KristensenCssMinifier();
_jsMinifier = jsMinifier ?? new CrockfordJsMinifier();
_htmlParser = new HtmlParser(new HtmlParsingHandlers
{
XmlDeclaration = XmlDeclarationHandler,
Doctype = DoctypeHandler,
Comment = CommentHandler,
IfConditionalComment = IfConditionalCommentHandler,
EndIfConditionalComment = EndIfConditionalCommentHandler,
StartTag = StartTagHandler,
EndTag = EndTagHandler,
Text = TextHandler,
EmbeddedCode = EmbeddedCodeHandler,
TemplateTag = TemplateTagHandler,
IgnoredFragment = IgnoredFragmentHandler
});
_buffer = new List<string>();
_errors = new List<MinificationErrorInfo>();
_warnings = new List<MinificationErrorInfo>();
_tagsWithNotRemovableWhitespaceQueue = new Queue<string>();
_currentNodeType = HtmlNodeType.Unknown;
_currentTag = null;
_currentText = string.Empty;
ISet<string> customAngularDirectivesWithExpressions = _settings.CustomAngularDirectiveCollection;
_angularDirectivesWithExpressions = customAngularDirectivesWithExpressions.Count > 0 ?
Utils.UnionHashSets(_builtinAngularDirectivesWithExpressions, customAngularDirectivesWithExpressions)
:
_builtinAngularDirectivesWithExpressions
;
}
/// <summary>
/// Checks whether attribute is the attribute <code>type</code> of tag <code>link</code>
/// or <code>style</code>, that containing CSS code
/// </summary>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>Result of check</returns>
private static bool IsCssTypeAttribute(HtmlTag tag, HtmlAttribute attribute)
{
string tagNameInLowercase = tag.NameInLowercase;
string attributeNameInLowercase = attribute.NameInLowercase;
string attributeValue = attribute.Value;
IList<HtmlAttribute> attributes = tag.Attributes;
bool isCssTypeAttribute = false;
if (tagNameInLowercase == "link" || tagNameInLowercase == "style")
{
string processedAttributeValue = attributeValue.Trim();
if (attributeNameInLowercase == "type" && processedAttributeValue.IgnoreCaseEquals(CSS_CONTENT_TYPE))
{
if (tagNameInLowercase == "link")
{
isCssTypeAttribute = attributes.Any(a => a.NameInLowercase == "rel"
&& a.Value.Trim().IgnoreCaseEquals("stylesheet"));
}
else if (tagNameInLowercase == "style")
{
isCssTypeAttribute = true;
}
}
}
return isCssTypeAttribute;
}
/// <summary>
/// Minify HTML content
/// </summary>
/// <param name="content">HTML content</param>
/// <param name="fileContext">File context</param>
/// <param name="encoding">Text encoding</param>
/// <param name="generateStatistics">Flag for whether to allow generate minification statistics</param>
/// <returns>Minification result</returns>
public MarkupMinificationResult Minify(string content, string fileContext, Encoding encoding,
bool generateStatistics)
{
MinificationStatistics statistics = null;
string cleanedContent = Utils.RemoveByteOrderMark(content);
string minifiedContent = string.Empty;
var errors = new List<MinificationErrorInfo>();
var warnings = new List<MinificationErrorInfo>();
lock (_minificationSynchronizer)
{
_fileContext = fileContext;
_encoding = encoding;
try
{
if (generateStatistics)
{
statistics = new MinificationStatistics(_encoding);
statistics.Init(cleanedContent);
}
int estimatedCapacity = (int)Math.Floor(cleanedContent.Length * AVERAGE_COMPRESSION_RATIO);
_result = StringBuilderPool.GetBuilder(estimatedCapacity);
_htmlParser.Parse(cleanedContent);
FlushBuffer();
if (_errors.Count == 0)
{
minifiedContent = _result.ToString();
if (generateStatistics)
{
statistics.End(minifiedContent);
}
}
}
catch (MarkupParsingException e)
{
WriteError(LogCategoryConstants.HtmlParsingError, e.Message, _fileContext,
e.LineNumber, e.ColumnNumber, e.SourceFragment);
}
finally
{
StringBuilderPool.ReleaseBuilder(_result);
_buffer.Clear();
_tagsWithNotRemovableWhitespaceQueue.Clear();
_currentNodeType = HtmlNodeType.Unknown;
_currentTag = null;
_currentText = string.Empty;
errors.AddRange(_errors);
warnings.AddRange(_warnings);
_errors.Clear();
_warnings.Clear();
_fileContext = null;
_encoding = null;
}
}
if (errors.Count == 0)
{
_logger.Info(LogCategoryConstants.HtmlMinificationSuccess,
string.Format(Strings.SuccesMessage_MarkupMinificationComplete, "HTML"),
fileContext, statistics);
}
return new MarkupMinificationResult(minifiedContent, errors, warnings, statistics);
}
/// <summary>
/// Checks whether the tag is a META content-type tag
/// </summary>
/// <param name="tag">Tag</param>
/// <returns>Result of check (true - is META content-type tag; false - is not META content-type tag)</returns>
private static bool IsMetaContentTypeTag(HtmlTag tag)
{
return tag.NameInLowercase == "meta" && tag.Attributes.Any(
a => a.NameInLowercase == "http-equiv" && a.Value.Trim().IgnoreCaseEquals("content-type"));
}
/// <summary>
/// Checks whether to minify whitespaces in text content of tag
/// </summary>
/// <param name="tag">Tag</param>
/// <returns>Result of check (true - can minify whitespaces; false - can not minify whitespaces)</returns>
private static bool CanMinifyWhitespace(HtmlTag tag)
{
return !_tagsWithNotRemovableWhitespace.Contains(tag.NameInLowercase);
}
/// <summary>
/// Checks whether to minify the Angular binding expression in attribute
/// </summary>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>Result of check (true - can minify expression; false - can not minify expression)</returns>
private bool CanMinifyAngularBindingExpressionInAttribute(HtmlTag tag, HtmlAttribute attribute)
{
string tagNameInLowercase = tag.NameInLowercase;
string attributeNameInLowercase = attribute.NameInLowercase;
IList<HtmlAttribute> attributes = tag.Attributes;
bool canMinify = false;
if (tag.Flags.HasFlag(HtmlTagFlags.Custom))
{
string elementDirectiveName = AngularHelpers.NormalizeDirectiveName(tagNameInLowercase);
switch (elementDirectiveName)
{
case "ngPluralize":
canMinify = attributeNameInLowercase == "count" || attributeNameInLowercase == "when";
break;
case "ngMessages":
canMinify = attributeNameInLowercase == "for";
break;
}
}
if (!canMinify)
{
string attributeDirectiveName = AngularHelpers.NormalizeDirectiveName(attributeNameInLowercase);
canMinify = ContainsAngularBindingExpression(attributeDirectiveName);
if (!canMinify)
{
switch (attributeDirectiveName)
{
case "ngTrueValue":
case "ngFalseValue":
canMinify = tagNameInLowercase == "input" && attributes.Any(
a => a.NameInLowercase == "type" && a.Value.Trim().IgnoreCaseEquals("checkbox"));
break;
}
}
}
return canMinify;
}
/// <summary>
/// Checks whether remove an the attribute, that has empty value
/// </summary>
/// <param name="tag">Tag</param>
/// <param name="attribute">Attribute</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private static bool CanRemoveEmptyAttribute(HtmlTag tag, HtmlAttribute attribute)
{
string tagNameInLowercase = tag.NameInLowercase;
string attributeNameInLowercase = attribute.NameInLowercase;
string attributeValue = attribute.Value;
HtmlAttributeType attributeType = attribute.Type;
bool result = false;
bool isZeroLengthString = attributeValue.Length == 0;
if (isZeroLengthString || string.IsNullOrWhiteSpace(attributeValue))
{
if (tagNameInLowercase == "input" && attributeNameInLowercase == "value")
{
result = isZeroLengthString;
}
else if (attributeType == HtmlAttributeType.Event
|| (tagNameInLowercase == "form" && attributeNameInLowercase == "action")
|| _emptyAttributesForRemoval.Contains(attributeNameInLowercase))
{
result = true;
}
}
return result;
}
/// <summary>
/// Start tags handler
/// </summary>
/// <param name="context">Markup parsing context</param>
/// <param name="tag">HTML tag</param>
private void StartTagHandler(MarkupParsingContext context, HtmlTag tag)
{
HtmlNodeType previousNodeType = _currentNodeType;
string previousTagName = string.Empty;
if (_currentTag != null)
{
previousTagName = _currentTag.Name;
}
if (_settings.UseMetaCharsetTag && IsMetaContentTypeTag(tag.Name, tag.Attributes))
{
tag = UpgradeToMetaCharsetTag(tag);
}
_currentNodeType = HtmlNodeType.StartTag;
_currentTag = tag;
_currentText = string.Empty;
string tagName = tag.Name;
IList<HtmlAttribute> attributes = tag.Attributes;
HtmlTagFlags tagFlags = tag.Flags;
// Set whitespace flags for nested tags (for example <span> within a <pre>)
WhitespaceMinificationMode whitespaceMinificationMode = _settings.WhitespaceMinificationMode;
if (whitespaceMinificationMode != WhitespaceMinificationMode.None)
{
if (_tagsWithNotRemovableWhitespaceQueue.Count == 0)
{
// Processing of whitespace, that followed before the start tag
bool allowTrimEnd = false;
if (tagFlags.Invisible || tagFlags.NonIndependent)
{
allowTrimEnd = true;
}
else
{
if (whitespaceMinificationMode == WhitespaceMinificationMode.Medium
|| whitespaceMinificationMode == WhitespaceMinificationMode.Aggressive)
{
allowTrimEnd = tagFlags.Block;
}
}
if (allowTrimEnd)
{
TrimEndLastBufferItem();
}
}
if (!CanMinifyWhitespace(tagName))
{
_tagsWithNotRemovableWhitespaceQueue.Enqueue(tagName);
}
}
if (_settings.RemoveOptionalEndTags
&& previousNodeType != HtmlNodeType.StartTag
&& !IsSafeOptionalEndTag(previousTagName))
{
if (CanRemoveOptionalEndTagByNextTagName(previousTagName, tagName))
{
RemoveLastEndTagFromBuffer(previousTagName);
}
FlushBuffer();
}
_buffer.Add("<");
_buffer.Add(tagName);
int attributeCount = attributes.Count;
for (int attributeIndex = 0; attributeIndex < attributeCount; attributeIndex++)
{
_buffer.Add(BuildAttributeString(context, tag, attributes[attributeIndex]));
}
if (tagFlags.Empty)
{
if (_settings.EmptyTagRenderMode == HtmlEmptyTagRenderMode.Slash)
{
_buffer.Add("/");
}
else if (_settings.EmptyTagRenderMode == HtmlEmptyTagRenderMode.SpaceAndSlash)
{
_buffer.Add(" /");
}
}
_buffer.Add(">");
}
/// <summary>
/// Checks whether remove an the tag, that has empty content
/// </summary>
/// <param name="tag">Tag</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private static bool CanRemoveTagWithoutContent(HtmlTag tag)
{
string tagNameInLowercase = tag.NameInLowercase;
HtmlTagFlags tagFlags = tag.Flags;
IList<HtmlAttribute> attributes = tag.Attributes;
return !(tagFlags.HasFlag(HtmlTagFlags.Custom)
|| (tagFlags.HasFlag(HtmlTagFlags.Xml) && tagFlags.HasFlag(HtmlTagFlags.NonIndependent))
|| _unremovableEmptyTags.Contains(tagNameInLowercase)
|| attributes.Any(a => IsCustomAttribute(a)
|| (_unremovableEmptyTagAttributes.Contains(a.NameInLowercase) && !string.IsNullOrWhiteSpace(a.Value))));
}
/// <summary>
/// Minify HTML content
/// </summary>
/// <param name="content">HTML content</param>
/// <param name="fileContext">File context</param>
/// <param name="encoding">Text encoding</param>
/// <param name="generateStatistics">Flag for whether to allow generate minification statistics</param>
/// <returns>Minification result</returns>
public MarkupMinificationResult Minify(string content, string fileContext, Encoding encoding,
bool generateStatistics)
{
MinificationStatistics statistics = null;
string minifiedContent = string.Empty;
var errors = new List<MinificationErrorInfo>();
var warnings = new List<MinificationErrorInfo>();
lock (_minificationSynchronizer)
{
_fileContext = fileContext;
_encoding = encoding;
try
{
if (generateStatistics)
{
statistics = new MinificationStatistics(_encoding);
statistics.Init(content);
}
_result = new StringBuilder(content.Length);
_buffer = new List<string>();
_errors = new List<MinificationErrorInfo>();
_warnings = new List<MinificationErrorInfo>();
_tagsWithNotRemovableWhitespaceQueue = new Queue<string>();
_currentNodeType = HtmlNodeType.Unknown;
_currentTag = null;
_currentText = string.Empty;
_htmlParser.Parse(content);
FlushBuffer();
if (_errors.Count == 0)
{
minifiedContent = _result.ToString();
if (generateStatistics)
{
statistics.End(minifiedContent);
}
}
}
catch (HtmlParsingException e)
{
WriteError(LogCategoryConstants.HtmlParsingError, e.Message, _fileContext,
e.LineNumber, e.ColumnNumber, e.SourceFragment);
}
finally
{
_result.Clear();
_buffer.Clear();
_tagsWithNotRemovableWhitespaceQueue.Clear();
_currentTag = null;
if (_errors.Count == 0)
{
_logger.Info(LogCategoryConstants.HtmlMinificationSuccess,
string.Format(Strings.SuccesMessage_MarkupMinificationComplete, "HTML"),
_fileContext, statistics);
}
errors.AddRange(_errors);
warnings.AddRange(_warnings);
_errors.Clear();
_warnings.Clear();
_fileContext = null;
_encoding = null;
}
}
return new MarkupMinificationResult(minifiedContent, errors, warnings, statistics);
}
/// <summary>
/// Checks whether remove whitespace after end non-independent tag
/// </summary>
/// <param name="endTag">End tag</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private static bool CanRemoveWhitespaceAfterEndNonIndependentTag(HtmlTag endTag)
{
string endTagNameInLowercase = endTag.NameInLowercase;
bool cannotRemove;
switch (endTagNameInLowercase)
{
case "li":
case "dt":
case "dd":
case "rt":
case "rp":
case "rb":
case "rtc":
cannotRemove = true;
break;
default:
cannotRemove = false;
break;
}
return !cannotRemove;
}
/// <summary>
/// Cleans a attribute value
/// </summary>
/// <param name="context">Markup parsing context</param>
/// <param name="tag">HTML tag</param>
/// <param name="attribute">HTML attribute</param>
/// <returns>Processed attribute value</returns>
private string CleanAttributeValue(MarkupParsingContext context, HtmlTag tag, HtmlAttribute attribute)
{
string attributeValue = attribute.Value;
if (attributeValue.Length == 0)
{
return attributeValue;
}
string result = attributeValue;
string tagName = tag.Name;
IList<HtmlAttribute> attributes = tag.Attributes;
string attributeName = attribute.Name;
HtmlAttributeType attributeType = attribute.Type;
if (attributeType != HtmlAttributeType.Event && MustacheStyleTagHelpers.ContainsMustacheStyleTag(result))
{
// Processing of Angular Mustache-style tags
var attributeValueBuilder = new StringBuilder();
MustacheStyleTagHelpers.ParseMarkup(result,
(localContext, expression, startDelimiter, endDelimiter) =>
{
string processedExpression = expression;
if (_settings.MinifyAngularBindingExpressions && startDelimiter == "{{" && endDelimiter == "}}")
{
processedExpression = MinifyAngularBindingExpression(context, attribute.ValueCoordinates,
localContext.NodeCoordinates, expression);
}
attributeValueBuilder.Append(startDelimiter);
attributeValueBuilder.Append(processedExpression);
attributeValueBuilder.Append(endDelimiter);
},
(localContext, textValue) =>
{
string processedTextValue = textValue;
if (attributeType == HtmlAttributeType.ClassName)
{
processedTextValue = Utils.CollapseWhitespace(textValue);
}
attributeValueBuilder.Append(processedTextValue);
}
);
result = attributeValueBuilder.ToString();
attributeValueBuilder.Clear();
switch (attributeType)
{
case HtmlAttributeType.Uri:
case HtmlAttributeType.Numeric:
case HtmlAttributeType.ClassName:
result = result.Trim();
break;
case HtmlAttributeType.Style:
result = result.Trim();
result = Utils.RemoveEndingSemicolon(result);
break;
default:
if (_settings.MinifyAngularBindingExpressions)
{
string elementDirectiveName = AngularHelpers.NormalizeDirectiveName(tagName);
if (elementDirectiveName == "ngPluralize" && attributeName == "when")
{
result = MinifyAngularBindingExpression(context, attribute.ValueCoordinates, result);
}
}
break;
}
}
else
{
switch (attributeType)
{
case HtmlAttributeType.Uri:
result = result.Trim();
if (result.StartsWith(HTTP_PROTOCOL, StringComparison.OrdinalIgnoreCase))
{
if (_settings.RemoveHttpProtocolFromAttributes && !ContainsRelExternalAttribute(attributes))
{
int httpProtocolLength = HTTP_PROTOCOL.Length;
result = result.Substring(httpProtocolLength);
}
}
else if (result.StartsWith(HTTPS_PROTOCOL, StringComparison.OrdinalIgnoreCase))
{
if (_settings.RemoveHttpsProtocolFromAttributes && !ContainsRelExternalAttribute(attributes))
{
int httpsProtocolLength = HTTPS_PROTOCOL.Length;
result = result.Substring(httpsProtocolLength);
}
}
else if (result == "href" && result.StartsWith(JS_PROTOCOL, StringComparison.OrdinalIgnoreCase))
{
result = ProcessInlineScriptContent(context, attribute);
}
break;
case HtmlAttributeType.Numeric:
result = result.Trim();
break;
case HtmlAttributeType.ClassName:
if (AngularHelpers.IsClassDirective(result))
{
// Processing of Angular class directives
string ngOriginalDirectiveName = string.Empty;
string ngNormalizedDirectiveName = string.Empty;
string ngExpression;
var ngDirectives = new Dictionary<string, string>();
AngularHelpers.ParseClassDirective(result,
(localContext, originalDirectiveName, normalizedDirectiveName) =>
{
ngOriginalDirectiveName = originalDirectiveName;
ngNormalizedDirectiveName = normalizedDirectiveName;
ngExpression = null;
ngDirectives.Add(ngOriginalDirectiveName, ngExpression);
},
(localContext, expression) =>
{
ngExpression = expression;
if (_settings.MinifyAngularBindingExpressions
&& ContainsAngularBindingExpression(ngNormalizedDirectiveName))
{
ngExpression = MinifyAngularBindingExpression(context,
attribute.ValueCoordinates, localContext.NodeCoordinates,
expression);
}
ngDirectives[ngOriginalDirectiveName] = ngExpression;
},
localContext =>
{
if (ngDirectives[ngOriginalDirectiveName] == null)
{
ngDirectives[ngOriginalDirectiveName] = string.Empty;
}
}
);
int directiveCount = ngDirectives.Count;
if (directiveCount > 0)
{
var directiveBuilder = new StringBuilder();
int directiveIndex = 0;
int lastDirectiveIndex = directiveCount - 1;
string previousExpression = null;
foreach (var directive in ngDirectives)
{
string directiveName = directive.Key;
string expression = directive.Value;
if (directiveIndex > 0 && (expression == null || previousExpression == null))
{
directiveBuilder.Append(" ");
}
directiveBuilder.Append(directiveName);
if (!string.IsNullOrWhiteSpace(expression))
{
directiveBuilder.AppendFormat(":{0}", expression);
}
if (directiveIndex < lastDirectiveIndex && expression != null)
{
directiveBuilder.Append(";");
}
previousExpression = expression;
directiveIndex++;
}
result = directiveBuilder.ToString();
directiveBuilder.Clear();
}
else
{
result = string.Empty;
}
}
else
{
result = result.Trim();
result = Utils.CollapseWhitespace(result);
}
break;
case HtmlAttributeType.Style:
result = ProcessInlineStyleContent(context, attribute);
break;
case HtmlAttributeType.Event:
result = ProcessInlineScriptContent(context, attribute);
break;
default:
if (attributeName == "data-bind" && _settings.MinifyKnockoutBindingExpressions)
{
result = MinifyKnockoutBindingExpression(context, attribute);
}
else if (tagName == "meta" && attributeName == "content"
&& attributes.Any(a => a.Name == "name" && a.Value.Trim().IgnoreCaseEquals("keywords")))
{
result = result.Trim();
result = Utils.CollapseWhitespace(result);
result = _separatingCommaWithSpacesRegex.Replace(result, ",");
result = _endingCommaWithSpacesRegex.Replace(result, string.Empty);
}
else
{
if (_settings.MinifyAngularBindingExpressions
&& CanMinifyAngularBindingExpressionInAttribute(tagName, attributeName, attributes))
{
result = MinifyAngularBindingExpression(context, attribute.ValueCoordinates, result);
}
}
break;
}
}
return result;
}
/// <summary>
/// Checks whether remove whitespace after end non-independent tag by parent tag
/// </summary>
/// <param name="endTag">End tag</param>
/// <param name="parentTag">Parent tag</param>
/// <returns>Result of check (true - can be removed; false - can not be removed)</returns>
private static bool CanRemoveWhitespaceAfterEndNonIndependentTagByParentTag(HtmlTag endTag, HtmlTag parentTag)
{
string endTagNameInLowercase = endTag.NameInLowercase;
string parentTagNameInLowercase = parentTag.NameInLowercase;
bool canRemove;
switch (endTagNameInLowercase)
{
case "li":
canRemove = parentTagNameInLowercase == "ul" || parentTagNameInLowercase == "ol"
|| parentTagNameInLowercase == "menu";
break;
case "dt":
case "dd":
canRemove = parentTagNameInLowercase == "dl";
break;
default:
canRemove = false;
break;
}
return canRemove;
}
/// <summary>
/// Parses a start tag
/// </summary>
/// <param name="tagName">Tag name</param>
/// <param name="tagNameInLowercase">Tag name in lowercase</param>
/// <param name="attributesString">String representation of the attribute list</param>
/// <param name="attributesCoordinates">Attributes coordinates</param>
/// <param name="isEmptyTag">Flag that tag is empty</param>
private void ParseStartTag(string tagName, string tagNameInLowercase, string attributesString,
SourceCodeNodeCoordinates attributesCoordinates, bool isEmptyTag)
{
HtmlTagFlags tagFlags = GetTagFlagsByName(tagNameInLowercase);
if (tagFlags.HasFlag(HtmlTagFlags.Optional))
{
HtmlTag lastStackedTag = _tagStack.LastOrDefault();
if (lastStackedTag != null && lastStackedTag.NameInLowercase == tagNameInLowercase)
{
ParseEndTag(lastStackedTag.Name, lastStackedTag.NameInLowercase);
}
else
{
if (tagNameInLowercase == "body" && _tagStack.Any(t => t.NameInLowercase == "head"))
{
HtmlTag headTag = _tagStack.Single(t => t.NameInLowercase == "head");
ParseEndTag(headTag.Name, headTag.NameInLowercase);
}
}
}
if (tagFlags.HasFlag(HtmlTagFlags.Empty))
{
isEmptyTag = true;
}
else if (isEmptyTag)
{
tagFlags |= HtmlTagFlags.Empty;
}
var attributes = ParseAttributes(tagName, tagNameInLowercase, tagFlags,
attributesString, attributesCoordinates);
var tag = new HtmlTag(tagName, tagNameInLowercase, attributes, tagFlags);
if (!isEmptyTag)
{
if (_conditionalCommentOpened)
{
HtmlConditionalComment lastConditionalComment = _conditionalCommentStack.Peek();
HtmlConditionalCommentType lastConditionalCommentType = lastConditionalComment.Type;
if (tagFlags.HasFlag(HtmlTagFlags.EmbeddedCode)
|| lastConditionalCommentType == HtmlConditionalCommentType.RevealedValidating
|| lastConditionalCommentType == HtmlConditionalCommentType.RevealedValidatingSimplified)
{
_tagStack.Add(tag);
}
}
else
{
_tagStack.Add(tag);
}
}
if (_handlers.StartTag != null)
{
_handlers.StartTag(_context, tag);
}
if (tagFlags.HasFlag(HtmlTagFlags.Xml) && !tagFlags.HasFlag(HtmlTagFlags.NonIndependent))
{
_xmlTagStack.Push(tagNameInLowercase);
}
}
/// <summary>
/// Parses HTML content
/// </summary>
/// <param name="content">HTML content</param>
public void Parse(string content)
{
int contentLength = content.Length;
if (contentLength == 0)
{
return;
}
lock (_parsingSynchronizer)
{
_innerContext = new InnerMarkupParsingContext(content);
_context = new MarkupParsingContext(_innerContext);
int endPosition = contentLength - 1;
int previousPosition = -1;
try
{
while (_innerContext.Position <= endPosition)
{
bool isProcessed = false;
HtmlTag lastStackedTag = _tagStack.LastOrDefault();
// Make sure we're not in a tag, that contains embedded code
if (lastStackedTag == null || !lastStackedTag.Flags.IsSet(HtmlTagFlags.EmbeddedCode))
{
if (_innerContext.PeekCurrentChar() == '<')
{
switch (_innerContext.PeekNextChar())
{
case char c when c.IsAlphaNumeric():
// Start tag
isProcessed = ProcessStartTag();
break;
case '/':
if (_innerContext.PeekNextChar().IsAlphaNumeric())
{
// End tag
isProcessed = ProcessEndTag();
}
break;
case '!':
switch (_innerContext.PeekNextChar())
{
case '-':
if (_innerContext.PeekNextChar() == '-')
{
// Comments
if (_innerContext.PeekNextChar() == '[')
{
// Revealed validating If conditional comments
// (e.g. <!--[if ... ]><!--> or <!--[if ... ]>-->)
isProcessed = ProcessRevealedValidatingIfComment();
if (!isProcessed)
{
// Hidden If conditional comments (e.g. <!--[if ... ]>)
isProcessed = ProcessHiddenIfComment();
}
}
else
{
// Revealed validating End If conditional comments
// (e.g. <!--<![endif]-->)
isProcessed = ProcessRevealedValidatingEndIfComment();
}
if (!isProcessed)
{
// HTML comments
isProcessed = ProcessComment();
}
}
break;
case '[':
switch (_innerContext.PeekNextChar())
{
case 'i':
case 'I':
// Revealed If conditional comment (e.g. <![if ... ]>)
isProcessed = ProcessRevealedIfComment();
break;
case 'e':
case 'E':
// Hidden End If conditional comment (e.g. <![endif]-->)
isProcessed = ProcessHiddenEndIfComment();
if (!isProcessed)
{
// Revealed End If conditional comment (e.g. <![endif]>)
isProcessed = ProcessRevealedEndIfComment();
}
break;
case 'C':
// CDATA sections
isProcessed = ProcessCdataSection();
break;
}
break;
case 'D':
case 'd':
// Doctype declaration
isProcessed = ProcessDoctype();
break;
}
break;
case '?':
// XML declaration
isProcessed = ProcessXmlDeclaration();
break;
}
}
if (!isProcessed)
{
// Text
ProcessText();
}
}
else
{
// Embedded code
ProcessEmbeddedCode();
}
if (_innerContext.Position == previousPosition)
{
throw new MarkupParsingException(
string.Format(Strings.ErrorMessage_MarkupParsingFailed, "HTML"),
_innerContext.NodeCoordinates, _innerContext.GetSourceFragment());
}
previousPosition = _innerContext.Position;
}
// Clean up any remaining tags
ParseEndTag();
// Check whether there were not closed conditional comment
if (_conditionalCommentStack.Count > 0)
{
throw new MarkupParsingException(
Strings.ErrorMessage_NotClosedConditionalComment,
_innerContext.NodeCoordinates, _innerContext.GetSourceFragment());
}
}
catch (MarkupParsingException)
{
throw;
}
finally
{
_tagStack.Clear();
_tempAttributes.Clear();
_conditionalCommentStack.Clear();
_conditionalCommentOpened = false;
_xmlTagStack.Clear();
_context = null;
_innerContext = null;
}
}
}