在 XPath 中是否可以将 OR 运算符与节点名称一起使用? [英] In XPath is it possible to use the OR operator with node names?

问题描述

使用 XPath，我知道您可以通过以下方式使用联合运算符:

//*[@id="Catalog"]/thead |//*[@id="目录"]/tbody

这对我来说似乎有点尴尬.有没有办法做类似于其中之一的事情?

//*[@id="Catalog"]/(thead|tbody)//*[@id="目录"]/(thead 或 tbody)//*[@id="Catalog"]/*[nodename="thead" 或 nodename="tbody"]

这对我来说似乎更具可读性和直观性...

解决方案

虽然表达式:

<块引用>

//*[@id="Catalog"]/*[name()="thead" or name()="tbody"]

正确

这个表达式更有效:

//*[@id="Catalog"]/*[self::thead 或 self::tbody]

还有第三种方法可以检查元素的名称是否是指定的字符串序列之一:

//*[@id="Catalog"]/*[contains('|thead|tbody|',concat('|',name(),'|'))]

在可能名称的数量非常长的情况下，使用最后一种技术特别实用(无限且未知长度).管道分隔的可能名称字符串甚至可以作为外部参数传递给转换，这大大增加了其通用性、可重用性和DRY"性.

With XPath, I know that you can use the union operator in the following way:

//*[@id="Catalog"]/thead | //*[@id="Catalog"]/tbody

This seems to be a little awkward to me though. Is there a way to do something similar to one of these instead?

//*[@id="Catalog"]/(thead|tbody)
//*[@id="Catalog"]/(thead or tbody)
//*[@id="Catalog"]/*[nodename="thead" or nodename="tbody"]

That seems a lot more readable and intuitive to me...

解决方案

While the expression:

//*[@id="Catalog"]/*[name()="thead" or name()="tbody"]

is correct

This expression is more efficient:

//*[@id="Catalog"]/*[self::thead or self::tbody]

There is yet a third way to check if the name of an element is one of a specified sequence of strings:

//*[@id="Catalog"]/*[contains('|thead|tbody|',concat('|',name(),'|'))]

Using this last technique can be especially practical in case the number of possible names is very long (of unlimited and unknown length). The pipe-delimited string of possible names can even be passed as an external parameter to the transformation, which greatly increases its generality, re-usability and "DRY"-ness.

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