jQuery.htmlPrefilter()

分类: Manipulation

jQuery.htmlPrefilter( html )返回: String

描述: 通过jQuery操作方法修改和过滤HTML字符串。

这种方法很少需要直接调用。反而可以使用这个方法作为修改现有jQuery操作方法的一个切入点。 例如，从传入HTML字符串中删除所有<del>标签，可以这么做：

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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, "" );
};

这个函数也可以被重写，以便绕过某些边缘情况的问题。 jQuery中默认的htmlPrefilter函数将贪婪地确保所有的标签都符合XHTML标准。 这意味着包括任何看起来像一个HTML标签的内容，但实际上他可能是一个字符串 (例如

<a title="<div />"><>
) 。 jQuery.htmlPrefilter()函数可以绕过他:

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

然而，尽管上述解决办法非常简短， 它把负担给你，确保在任何HTML字符串都符合XHTML标准。 此问题的更彻底的解决将是这样的：

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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 );
};