我正在尝试创建一个删除不在白名单中的html标签和属性的函数。 我有以下HTML：
<b>first text </b>
<b>second text here
<a>some text here</a>
<a>some text here</a>
</b>
<a>some twxt here</a>
我正在使用HTML敏捷包，到目前为止我的代码是：
static List<string> WhiteNodeList = new List<string> { "b" };
static List<string> WhiteAttrList = new List<string> { };
static HtmlNode htmlNode;
public static void RemoveNotInWhiteList(out string _output, HtmlNode pNode, List<string> pWhiteList, List<string> attrWhiteList)
{
// remove all attributes not on white list
foreach (var item in pNode.ChildNodes)
{
item.Attributes.Where(u => attrWhiteList.Contains(u.Name) == false).ToList().ForEach(u => RemoveAttribute(u));
}
// remove all html and their innerText and attributes if not on whitelist.
//pNode.ChildNodes.Where(u => pWhiteList.Contains(u.Name) == false).ToList().ForEach(u => u.Remove());
//pNode.ChildNodes.Where(u => pWhiteList.Contains(u.Name) == false).ToList().ForEach(u => u.ParentNode.ReplaceChild(ConvertHtmlToNode(u.InnerHtml),u));
//pNode.ChildNodes.Where(u => pWhiteList.Contains(u.Name) == false).ToList().ForEach(u => u.Remove());
for (int i = 0; i < pNode.ChildNodes.Count; i++)
{
if (!pWhiteList.Contains(pNode.ChildNodes[i].Name))
{
HtmlNode _newNode = ConvertHtmlToNode(pNode.ChildNodes[i].InnerHtml);
pNode.ChildNodes[i].ParentNode.ReplaceChild(_newNode, pNode.ChildNodes[i]);
if (pNode.ChildNodes[i].HasChildNodes && !string.IsNullOrEmpty(pNode.ChildNodes[i].InnerText.Trim().Replace("\r\n", "")))
{
HtmlNode outputNode1 = pNode.ChildNodes[i];
for (int j = 0; j < pNode.ChildNodes[i].ChildNodes.Count; j++)
{
string _childNodeOutput;
RemoveNotInWhiteList(out _childNodeOutput,
pNode.ChildNodes[i], WhiteNodeList, WhiteAttrList);
pNode.ChildNodes[i].ReplaceChild(ConvertHtmlToNode(_childNodeOutput), pNode.ChildNodes[i].ChildNodes[j]);
i++;
}
}
}
}
// Console.WriteLine(pNode.OuterHtml);
_output = pNode.OuterHtml;
}
private static void RemoveAttribute(HtmlAttribute u)
{
u.Value = u.Value.ToLower().Replace("javascript", "");
u.Remove();
}
public static HtmlNode ConvertHtmlToNode(string html)
{
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(html);
if (doc.DocumentNode.ChildNodes.Count == 1)
return doc.DocumentNode.ChildNodes[0];
else return doc.DocumentNode;
}
我尝试实现的输出是
<b>first text </b>
<b>second text here
some text here
some text here
</b>
some twxt here
这意味着我只想保留<b>标签
我这样做的原因是因为有些用户将MS WORD中的cpoy-paste粘贴到ny WYSYWYG html编辑器中。
感谢！
答案 0 :(得分：31)
using System.Collections.Generic;
using System.Linq;
using HtmlAgilityPack;
namespace Wayloop.Blog.Core.Markup
{
public static class HtmlSanitizer
{
private static readonly IDictionary<string, string[]> Whitelist;
static HtmlSanitizer()
{
Whitelist = new Dictionary<string, string[]> {
{ "a", new[] { "href" } },
{ "strong", null },
{ "em", null },
{ "blockquote", null },
};
}
public static string Sanitize(string input)
{
var htmlDocument = new HtmlDocument();
htmlDocument.LoadHtml(input);
SanitizeNode(htmlDocument.DocumentNode);
return htmlDocument.DocumentNode.WriteTo().Trim();
}
private static void SanitizeChildren(HtmlNode parentNode)
{
for (int i = parentNode.ChildNodes.Count - 1; i >= 0; i--) {
SanitizeNode(parentNode.ChildNodes[i]);
}
}
private static void SanitizeNode(HtmlNode node)
{
if (node.NodeType == HtmlNodeType.Element) {
if (!Whitelist.ContainsKey(node.Name)) {
node.ParentNode.RemoveChild(node);
return;
}
if (node.HasAttributes) {
for (int i = node.Attributes.Count - 1; i >= 0; i--) {
HtmlAttribute currentAttribute = node.Attributes[i];
string[] allowedAttributes = Whitelist[node.Name];
if (!allowedAttributes.Contains(currentAttribute.Name)) {
node.Attributes.Remove(currentAttribute);
}
}
}
}
if (node.HasChildNodes) {
SanitizeChildren(node);
}
}
}
}
I got HtmlSanitizer from here 显然它不剥离标签，但删除元素altoghether。
好的，这是以后需要的人的解决方案。
public static class HtmlSanitizer
{
private static readonly IDictionary<string, string[]> Whitelist;
private static List<string> DeletableNodesXpath = new List<string>();
static HtmlSanitizer()
{
Whitelist = new Dictionary<string, string[]> {
{ "a", new[] { "href" } },
{ "strong", null },
{ "em", null },
{ "blockquote", null },
{ "b", null},
{ "p", null},
{ "ul", null},
{ "ol", null},
{ "li", null},
{ "div", new[] { "align" } },
{ "strike", null},
{ "u", null},
{ "sub", null},
{ "sup", null},
{ "table", null },
{ "tr", null },
{ "td", null },
{ "th", null }
};
}
public static string Sanitize(string input)
{
if (input.Trim().Length < 1)
return string.Empty;
var htmlDocument = new HtmlDocument();
htmlDocument.LoadHtml(input);
SanitizeNode(htmlDocument.DocumentNode);
string xPath = HtmlSanitizer.CreateXPath();
return StripHtml(htmlDocument.DocumentNode.WriteTo().Trim(), xPath);
}
private static void SanitizeChildren(HtmlNode parentNode)
{
for (int i = parentNode.ChildNodes.Count - 1; i >= 0; i--)
{
SanitizeNode(parentNode.ChildNodes[i]);
}
}
private static void SanitizeNode(HtmlNode node)
{
if (node.NodeType == HtmlNodeType.Element)
{
if (!Whitelist.ContainsKey(node.Name))
{
if (!DeletableNodesXpath.Contains(node.Name))
{
//DeletableNodesXpath.Add(node.Name.Replace("?",""));
node.Name = "removeableNode";
DeletableNodesXpath.Add(node.Name);
}
if (node.HasChildNodes)
{
SanitizeChildren(node);
}
return;
}
if (node.HasAttributes)
{
for (int i = node.Attributes.Count - 1; i >= 0; i--)
{
HtmlAttribute currentAttribute = node.Attributes[i];
string[] allowedAttributes = Whitelist[node.Name];
if (allowedAttributes != null)
{
if (!allowedAttributes.Contains(currentAttribute.Name))
{
node.Attributes.Remove(currentAttribute);
}
}
else
{
node.Attributes.Remove(currentAttribute);
}
}
}
}
if (node.HasChildNodes)
{
SanitizeChildren(node);
}
}
private static string StripHtml(string html, string xPath)
{
HtmlDocument htmlDoc = new HtmlDocument();
htmlDoc.LoadHtml(html);
if (xPath.Length > 0)
{
HtmlNodeCollection invalidNodes = htmlDoc.DocumentNode.SelectNodes(@xPath);
foreach (HtmlNode node in invalidNodes)
{
node.ParentNode.RemoveChild(node, true);
}
}
return htmlDoc.DocumentNode.WriteContentTo(); ;
}
private static string CreateXPath()
{
string _xPath = string.Empty;
for (int i = 0; i < DeletableNodesXpath.Count; i++)
{
if (i != DeletableNodesXpath.Count - 1)
{
_xPath += string.Format("//{0}|", DeletableNodesXpath[i].ToString());
}
else _xPath += string.Format("//{0}", DeletableNodesXpath[i].ToString());
}
return _xPath;
}
}
我重命名了节点，因为如果我必须解析XML命名空间节点，它将在xpath解析时崩溃。
答案 1 :(得分：8)
感谢代码 - 伟大的事情!!!!
我做了很少的优化......
class TagSanitizer
{
List<HtmlNode> _deleteNodes = new List<HtmlNode>();
public static void Sanitize(HtmlNode node)
{
new TagSanitizer().Clean(node);
}
void Clean(HtmlNode node)
{
CleanRecursive(node);
for (int i = _deleteNodes.Count - 1; i >= 0; i--)
{
HtmlNode nodeToDelete = _deleteNodes[i];
nodeToDelete.ParentNode.RemoveChild(nodeToDelete, true);
}
}
void CleanRecursive(HtmlNode node)
{
if (node.NodeType == HtmlNodeType.Element)
{
if (Config.TagsWhiteList.ContainsKey(node.Name) == false)
{
_deleteNodes.Add(node);
}
else if (node.HasAttributes)
{
for (int i = node.Attributes.Count - 1; i >= 0; i--)
{
HtmlAttribute currentAttribute = node.Attributes[i];
string[] allowedAttributes = Config.TagsWhiteList[node.Name];
if (allowedAttributes != null)
{
if (allowedAttributes.Contains(currentAttribute.Name) == false)
{
node.Attributes.Remove(currentAttribute);
}
}
else
{
node.Attributes.Remove(currentAttribute);
}
}
}
}
if (node.HasChildNodes)
{
node.ChildNodes.ToList().ForEach(v => CleanRecursive(v));
}
}
}