[frus] Restore link from page image view to document

[joewiz]

On the old hsg, page image views had a sidebar that provided a link to the possible document(s) that the page contains. For example, page 510 of frus1952-54v07p1 (visible at https://history.state.gov/historicaldocuments/frus1952-54v07p1/pg_510) contains the end of document 213 and the beginning of document 214. The sidebar:

The new site lacks this sidebar. The code we used to look up the possible documents belonging to a page number reference was:

declare function docs:sideright-documents($page) {
    let $scope := $page//tei:div[@type='document']
    let $sidebar :=
        if ($scope) then
            <div class="bordered resources">
                <h3>Show full text of the document{if (count($scope) gt 1) then 's' else ()} on this page</h3>
                <ul>{
                    for $div in $scope
                    let $xmlid := $div/@xml:id/string()
                    let $n := $div/@n/string()
                    order by $xmlid
                    return
                        <li><a href="/{$docs:view-name}/{$volume}/{$xmlid}">Document {$n}</a></li>
                }</ul>
            </div>
        else ()
    return $sidebar
};

The calling function supplies the $page argument, containing a reconstructed fragment of the text between the two <pb> milestones:

let $this-page := $target (: the <pb> requested from the URL :)
let $next-page := $this-page/following::tei:pb[1]
let $next-page-starts-document := $next-page/preceding-sibling::element()[1][self::tei:head] or (not($next-page/preceding-sibling::element()) and $next-page/parent::tei:div/@type = 'document')
let $fragment-ending-this-page :=
    if ($next-page-starts-document) then
        $next-page/parent::tei:div
    else 
        $next-page
let $page := 
    util:parse(util:get-fragment-between($this-page, $fragment-ending-this-page, true(), true()))

[plutonik-a]

@joewiz
Question about the requirements of this issue:

1. The sidebar in https://history.state.gov/historicaldocuments/frus1952-54v07p1/pg_510
   <pb xml:id="pg_510" n="510" facs="0544"/>
   provides the links to
   https://history.state.gov/historicaldocuments/frus1952-54v07p1/d213
   and
   https://history.state.gov/historicaldocuments/frus1952-54v07p1/d214.
   or
2. The sidebar provides "buttons" to display the content between <pb xml:id="pg_510" n="510" facs="0544"/> and <pb xml:id="pg_511" n="511" facs="0545"/> etc. at the end of the page, under the image.

It's unclear to me, because I can't see a working example anymore.
By the way, what does $docs:view-name in the <a> tag stand for in your code example?

[joewiz]

@plutonik-a Good question. The sidebar in https://history.state.gov/historicaldocuments/frus1952-54v07p1/pg_510 should provide links to d213 and d214. Perhaps a clearer label for the sidebar should be: "Documents shown on this page."

Sorry, in the code sample from the old site $docs:view-name resolved to /historicaldocuments/.