Orbeon Forms - 验证正则表达式前瞻

Question

我想在文本字段上使用正则表达式验证公式。这是纯正则表达式：

^(?!(?:\D*\d){7})\d+(\.\d{1,2})?$

当我在正则表达式在线工具（例如：https://regex101.com/）中测试这个表达式时，一切正常。但是当我尝试像这样在 Orbeon 中使用它作为验证器时：

matches(string(.), '^(?!(?:\D*\d){7})\d+(\.\d{1,2})?$')  or xxf:is-blank(string(.))

我收到错误 'Incorrect XPath expression'。

当我从正则表达式先行部分中删除后，我就可以使用它了。

matches(string(.), '^\d+(\.\d{1,2})?$')  or xxf:is-blank(string(.))

Orbeon Forms 是否支持正则表达式先行？正则表达式前瞻： https://www.regular-expressions.info/lookaround.html

Answer 1

重写表达式而不向前看。它匹配不超过 6 位的字符串。

使用

^(\d{1,4}(\.\d{1,2})?|\d{5}(\.\d)?|\d{6})$

见proof

解释

NODE                     EXPLANATION
--------------------------------------------------------------------------------
  ^                        the beginning of the string
--------------------------------------------------------------------------------
  (                        group and capture to :
--------------------------------------------------------------------------------
    \d{1,4}                  digits (0-9) (between 1 and 4 times
                             (matching the most amount possible))
--------------------------------------------------------------------------------
    (                        group and capture to  (optional
                             (matching the most amount possible)):
--------------------------------------------------------------------------------
      \.                       '.'
--------------------------------------------------------------------------------
      \d{1,2}                  digits (0-9) (between 1 and 2 times
                               (matching the most amount possible))
--------------------------------------------------------------------------------
    )?                       end of  (NOTE: because you are using a
                             quantifier on this capture, only the
                             LAST repetition of the captured pattern
                             will be stored in )
--------------------------------------------------------------------------------
   |                        OR
--------------------------------------------------------------------------------
    \d{5}                    digits (0-9) (5 times)
--------------------------------------------------------------------------------
    (                        group and capture to  (optional
                             (matching the most amount possible)):
--------------------------------------------------------------------------------
      \.                       '.'
--------------------------------------------------------------------------------
      \d                       digits (0-9)
--------------------------------------------------------------------------------
    )?                       end of  (NOTE: because you are using a
                             quantifier on this capture, only the
                             LAST repetition of the captured pattern
                             will be stored in )
--------------------------------------------------------------------------------
   |                        OR
--------------------------------------------------------------------------------
    \d{6}                    digits (0-9) (6 times)
--------------------------------------------------------------------------------
  )                        end of 
--------------------------------------------------------------------------------
  $                        before an optional \n, and the end of the
                           string

Orbeon Forms - 验证正则表达式前瞻

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