/// <summary>
/// 创建带范畴限定的选择器
/// </summary>
/// <param name="expression">选择器表达式</param>
/// <param name="scope">范畴限定，上溯时不超出此范畴</param>
/// <returns>带范畴限定的层叠选择器</returns>
public static ISelector Create(IHtmlContainer scope, string expression)
{
if (scope == null)
{
throw new ArgumentNullException("scope");
}
if (expression == null)
{
throw new ArgumentNullException("expression");
}
return(CssCasecadingSelector.Create(new CssAncetorRelativeSelector(new ContainerRestrict(scope)), CssParser.ParseSelector(expression)));
}
/// <summary>
/// 在元素集所有子代元素中使用 CSS 选择器选出符合要求的元素
/// </summary>
/// <param name="elements">作为选择范围的元素集</param>
/// <param name="expression">CSS 选择器表达式</param>
/// <returns>符合选择器的所有子代</returns>
public static IEnumerable <IHtmlElement> Find(this IEnumerable <IHtmlElement> elements, string expression)
{
if (!elements.Any())
{
return(Enumerable.Empty <IHtmlElement>());
}
if (elements.IsSingle())
{
return(elements.Single().Find(expression));
}
var document = elements.First().Document;
if (elements.Any(e => !e.Document.Equals(document)))
{
throw new InvalidOperationException("不支持在不同的文档中搜索");
}
var selector = CssCasecadingSelector.Create(elements, expression);
return(selector.Filter(document.Descendants()));
}
/// <summary>
/// 创建层叠选择器
/// </summary>
/// <param name="leftSelector">左选择器</param>
/// <param name="combanitor">结合符</param>
/// <param name="rightSelector">右选择器</param>
/// <returns>层叠选择器</returns>
private static ISelector CreateCasecadingSelector(ISelector leftSelector, char combanitor, CssElementSelector rightSelector)
{
return(CssCasecadingSelector.Create(leftSelector, combanitor, rightSelector));
}
public static ISelector Combine(CssRelativeSelector relativeSelector, CssMultipleSelector multipleSelector)
{
return(new CssMultipleSelector(multipleSelector._selectors.Select(selector => CssCasecadingSelector.Create(relativeSelector, selector)).ToArray()));
}
