如何使用Groovy/gPath访问父XML元素

Question

使用下面的XML，谁能告诉我在Groovy（Gpath或Xpath）中如何在最左边的元素上执行select，并包含对正确父元素的引用？

<CompoundEmployee>
  <person>
    <person_id_external>21554</person_id_external>
    <employment_information>
      <start_date>2014-02-27</start_date>
      <job_information><end_date>2013-04-21</end_date><event>H</event><start_date>2012-09-28</start_date></job_information>
      <job_information><end_date>2013-04-26</end_date><event>5</event><start_date>2013-04-22</start_date></job_information>
      <job_information><end_date>9999-12-31</end_date><event>R</event><start_date>2014-02-27</start_date></job_information>
    </employment_information>
  </person>
  <person>
    <person_id_external>8265</person_id_external>
    <employment_information>
      <start_date>2000-10-02</start_date>
      <job_information><end_date>2014-10-24</end_date><event>5</event><start_date>2014-05-22</start_date></job_information>
      <job_information><end_date>2014-05-21</end_date><event>H</event><start_date>2000-10-02</start_date></job_information>
      <job_information><end_date>9999-12-31</end_date><event>5</event><start_date>2014-10-25</start_date></job_information>
    </employment_information>
  </person>
  <execution_timestamp>2015-05-05T08:17:51.000Z</execution_timestamp>
  <version_id>1502P0</version_id>
</CompoundEmployee>

用英语编写的select语句是：

查询返回的元素必须包括来自employment_information的person_id_external，以及来自Job_Information的start_date。

到目前为止我已经试过了....

def xml = """ xml from above """
def list = new XmlSlurper().parseText(xml)
x = list.'**'.findAll { person ->
    person.event.text() in ['H','R'] && person.start_date.text() < list.person.employment_information.start_date.text()
} 
x.each { l -> println "Type -> ${l.event}, Start Date -> ${l.start_date}, End Date -> ${l.end_date}" }

当输入文件中只有一个人时，这种方法很有效，但当有多个雇员时，由于引用了错误的“list.person.employment_information.start_date”，即父/子节点不相关，结果就不正确。

类型->R，开始日期->2014-02-27，结束日期->9999-12-31

类型->H，开始日期->2000-10-02，结束日期->2014-05-21

实际上它应该只返回1行：

Answer 1

查询'**'并在那里命名varperson是误导性的，当您实际在那里搜索就业信息时。类似于这样：

def x = list.person.collectEntries{ person ->
    [person.person_id_external.text(), person.employment_information.job_information.findAll{ ji ->
        ji.event.text() in ['H','R'] && ji.start_date.text() < .person.employment_information.start_date.text()}}