jQuery.htmlPrefilter()

类别：文档处理

jQuery.htmlPrefilter( html )返回类型：String

描述：修改并筛选通过jQuery操纵方法传入的HTML字符串。

几乎不需要直接调用此方法。而是，使用它作为入口点，来修改已有的jQuery文档处理方法。例如：若要从进来的HTML字符串中删除所有的<del>标签，请这样做：

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var htmlPrefilter = $.htmlPrefilter,
  rdel = /<(del)(?=[\s>])[\w\W]*?<\/\1\s*>/gi;
 
$.htmlPrefilter = function( html ) {
  return htmlPrefilter.call( this, html ).replace( rdel, "" );
};

此函数将被覆盖重写，以绕过某些边缘问题。jQuery中默认的htmlProfilter函数将贪婪地确保所有标记都符合XHTML标准。这包括任何看起来像HTML标记，但实际上只是一个字符串的东西（例如，<a title="<div />"><>）。jQuery.htmlPrefilter()函数可用来绕过这：

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$.htmlPrefilter = function( html ) {
  // Return HTML strings unchanged
  return html;
};

上面的修复是简短明了的，与此同时，它给你带来了负担，以在任何HTML字符串中确保XHTML适用的标记。一个更彻底的修复这个问题将是：

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var panything = "[\\w\\W]*?",
 
  // Whitespace
  // https://html.spec.whatwg.org/multipage/infrastructure.html#space-character
  pspace = "[\\x20\\t\\r\\n\\f]",
 
  // End of tag name (whitespace or greater-than)
  pnameEnd = pspace.replace( "]", ">]" ),
 
  // Tag name (a leading letter, then almost anything)
  // https://html.spec.whatwg.org/multipage/syntax.html#tag-open-state
  // https://html.spec.whatwg.org/multipage/syntax.html#tag-name-state
  pname = "[a-z]" + pnameEnd.replace( "[", "[^/\\0" ) + "*",
 
  // Void element (end tag prohibited)
  // https://html.spec.whatwg.org/multipage/syntax.html#void-elements
  pvoidName = "(?:area|base|br|col|embed|hr|img|input|keygen|link|menuitem|meta|param|" +
    "source|track|wbr)(?=" + pnameEnd + ")",
 
  // Attributes (double-quoted value, single-quoted value, unquoted value, or no value)
  // https://html.spec.whatwg.org/multipage/syntax.html#attributes-2
  pattrs = "(?:" + pspace + "+[^\\0-\\x20\\x7f-\\x9f=\"'/>]+(?:" + pspace + "*=" + pspace +
    "*(?:\"" + panything + "\"|'" + panything + "'|" +
    pnameEnd.replace( "[", "[^" ) + "*(?!/)" +
    ")|))*" + pspace + "*",
 
  // Trailing content of a close tag
  pcloseTail = "(?:" + pspace + panything + "|)",
 
  rspecialHtml = new RegExp(
    // Non-void element that self-closes: $1–$5
    "(<)(?!" + pvoidName + ")(" + pname + ")(" + pattrs + ")(\\/)(>)|" +
      // No-innerHTML container (element, comment, or CDATA): $6
      "(<(script|style|textarea)" + pattrs + ">" + panything + "<\\/\\7" + pcloseTail + ">|" +
      "<!--" + panything + "--)",
    "gi"
  ),
 
  // "<"; element name; attributes; ">"; "<"; "/"; element name; ">"; no-innerHTML container
  pspecialReplacement = "$1$2$3$5$1$4$2$5$6";
 
$.htmlPrefilter = function( html ) {
  return ( html + "" ).replace( rspecialHtml, pspecialReplacement );
};