XQuery递归函数调用内部标签

Question

I'm trying to prepare an XML file to parse it JSON and its context is such as:

<user_manual>
  <embed-language_part id="SL14686180">
    <language_part id="1" role="-" lang="de">
      <embed-user_manual_part id="1">
        <user_manual_part id="1" role="-" document-type="IU">
          <embed-chapter id="1">
            <?ecls-start-embedded-resource resource="ecls_bio_becls_a3_a30660983"?>
            <chapter id="1" role="-" toctitle="yes" footrowtitle="no" type="security">
              <embed-title_module id="1">
                <title_module id="1" role="-">
                  <title id="1">Sicherheits- und Warnhinweise</title>
                </title_module>
              </embed-title_module>
              <embed-section id="1">
                <section id="1" footrowtitle="no" role="-" toctitle="yes">
                  <embed-section id="2">
                    <section id="2">
                      <embed-title_module id="2">
                        <title_module id="2" role="-">
                          <title id="2">Eisschale</title>
                        </title_module>
                      </embed-title_module>
                    </section>
                  </embed-section>
                  <embed-title_module id="3">
                    <title_module id="31" role="-">
                      <title id="3">Bevor Sie das Gerat in Betrieb nehmen</title>
                    </title_module>
                  </embed-title_module>
                </section>
              </embed-section>
            </chapter>
          </embed-chapter>
        </user_manual_part>
      </embed-user_manual_part>
    </language_part>
  </embed-language_part>
</user_manual>

I wrote an XQuery script regarding to my expectations first (assume that $doc is document, $matnr is 22333),

declare variable $doc external;
declare variable $matnr external;
<dmContainer>{
for $language in $doc/user_manual/embed-language_part/language_part
let $lang_code := data($language/@lang)
for $embed_chapter in $language/embed-user_manual_part/user_manual_part/embed-chapter
let $objectid := data($embed_chapter/processing-instruction('ecls-start-embedded-resource'))[1]  
let $fileattr := string($objectid)
let $filename := translate(substring-after($objectid,'resource='),'&quot;','')
let $postfix :=  substring(tokenize($filename,'_')[last()], 2)    

let $name := concat($matnr, '_', $postfix)                              
 return (element {$lang_code} {    
    attribute title {data($embed_chapter/chapter/embed-title_module/title_module/title)},
    attribute language {$lang_code},   
    attribute name {$name},        
    for $section in $embed_chapter/chapter/embed-section/section
        return <section title="{data($section/embed-title_module/title_module/title)}"></section>
})
}</dmContainer>

This returns:

<dmContainer>
   <de title="Sicherheits- und Warnhinweise" language="de" name="223333_30660983">
      <section title="Bevor Sie das Gerat in Betrieb nehmen" />
   </de>
</dmContainer>

Return contains the chapter element and its first section's title for the JSON but I have to add this one to all sections (the sections included by sections too).

According to the input XML the sections can have another sections (one or more) recursively. You can look the example by searching it deeply. The question is that how i can add these sections to my output with a proper recursive way(i mean not just the child level one level two children are included too) , i searched for some examples recursive functions of XQuery but i couldn't get any one.

Expected output:

 <dmContainer>
   <de title="Sicherheits- und Warnhinweise" language="de" name="223333_30660983">
      <section title="Bevor Sie das Gerat in Betrieb nehmen">
      <section title="Eisschale"/>
      </section>
   </de>
</dmContainer>

How can I get all sections?

Answer 1

If you just want all sections in that chapter (in document order), go with the descendant-or-self-step , abbreviated // .

for $section in $embed_chapter/chapter//embed-section/section
    return <section title="{data($section/embed-title_module/title_module/title)}"

If document order doesn't work out for you (eg., first the title of the current section, then all subsections on the current level, no matter if they actually precede the title), you will have to write your own function traversing the tree: a function that gets the current section, returns the title, and recursively calls itself for the direct subsections (if there are any).