/// <summary>
/// 检查元素是否为CDATA标签
/// </summary>
/// <param name="tag">元素开始标签</param>
/// <returns>是否为CDATA标签</returns>
protected virtual bool IsCDataElement(HtmlBeginTag tag)
{
return(HtmlSpecification.cdataTags.Contains(tag.TagName, StringComparer.OrdinalIgnoreCase));
}
/// <summary>
/// 检查元素是否为CDATA标签
/// </summary>
/// <param name="tag">元素开始标签</param>
/// <returns>是否为CDATA标签</returns>
protected virtual bool IsCDataElement(HtmlBeginTag tag)
{
return(HtmlSpecification.IsCDataElement(tag.TagName));
}
/// <summary>
/// 处理元素开始标签
/// </summary>
/// <param name="beginTag">开始标签信息</param>
/// <returns>处理过程中所创建的元素对象，若不支持则返回 null</returns>
protected virtual IHtmlElement ProcessBeginTag(HtmlBeginTag beginTag)
{
string tagName = beginTag.TagName;
bool selfClosed = beginTag.SelfClosed;
//检查是否为自结束标签，并作相应处理
if (IsSelfCloseElement(beginTag))
{
selfClosed = true;
}
//检查是否为CData标签，并作相应处理
if (IsCDataElement(beginTag))
{
Reader.EnterCDataMode(tagName.ToLowerInvariant());
}
//检查父级是否可选结束标记，并作相应处理
{
var element = CurrentContainer as IHtmlElement;
if (element != null && HtmlSpecification.optionalCloseTags.Contains(element.Name, StringComparer.OrdinalIgnoreCase))
{
if (ImmediatelyClose(tagName, element))
{
ContainerStack.Pop();
}
}
}
//处理所有属性
var attributes = new Dictionary <string, string>(StringComparer.OrdinalIgnoreCase);
foreach (var a in beginTag.Attributes)
{
string name = a.Name;
string value = a.Value;
if (value != null)
{
value = HtmlEncoding.HtmlDecode(value);
}
if (attributes.ContainsKey(name))//重复的属性名，只取第一个
{
continue;
}
attributes.Add(name, value);
}
//创建元素
{
var element = CreateElement(tagName, attributes);
//加入容器堆栈
if (!selfClosed)
{
ContainerStack.Push(element);
}
return(element);
}
}
/// <summary>
/// 检查元素是否为自结束标签
/// </summary>
/// <param name="tag">元素开始标签</param>
/// <returns>是否为自结束标签</returns>
protected virtual bool IsSelfCloseElement(HtmlBeginTag tag)
{
return(HtmlSpecification.IsForbiddenEndTag(tag.TagName));
}
