Hi Michael, > Manipulation of an XML structure .... with flexible declare function .... > > If there are some similar issues or solutions in BaseX community, > this will be very interesting. Any other sources to learn more about?
You can have a look at the lecture slides that are listed at [1], in particular “XQuery: More than Just a Query Language”. Our documentation contains various practical XQuery examples as well (see e.g. [2]). The 2nd edition of Priscilla Walmsley’s book is one of the best available printed resources [3]. It was published end of 2015, so it includes all new features of XQuery 3 and XQuery 3.1. It takes a while and efforts to explore the full complexity and variety of the XQuery language, but may save you a lot of time in the long term. Christian [1] http://phobos103.inf.uni-konstanz.de/xml15 [2] http://docs.basex.org/wiki/Update [3] http://shop.oreilly.com/product/0636920035589.do > Christian Grün hat am 29. Oktober 2017 um 17:10 geschrieben: > > > Hi Michael, > > Please note that an expression will always be evaluated before its > result will be bound to a variable. > > You didn’t mention what result you would expect. I guess it should be > as follows: > > textBBB > > You could pass on a path string to your function and navigate through > the single steps, e.g. with fold-left [1]: > > declare function local:node-add($xml, $path, $value) { > copy $copy := $xml > modify ( > let $target := fold-left( > tokenize($path, '/'), > $copy, > function($node, $step) { > $node/*[name() = $step] > } > ) > return insert node $value into $target > ) > return $copy > }; > > local:node-add( > text, > 'xml', > BBB > ) > > If you need more flexibility, you can pass on a function that takes > care of the navigation inside the copy/modify or update expression: > > declare function local:node-add($xml, $target, $value) { > $xml update { > insert node $value into $target(.) > } > }; > local:node-add( > document { }, > function($n) { $n/A/B }, > > ) > > Best, > Christian > > [1] http://docs.basex.org/wiki/Higher-Order_Functions#fn:fold-left > > > > On Sun, Oct 29, 2017 at 4:34 PM, wrote: > > Hello, > > How to add/replace a complete node in a node tree, > with done by a function and by according function parameters. > That means with flexible instructions. > > Such as: > > declare function local:NodeAdd($XML, $XMLPath, $XMLValue) > { > ?? > }; > > let $XML := text > let $XMLAdd := BBB > let $XMLPath := $XML/xml > > > return > local:NodeAdd($XML, $XMLPath , $XMLAdd) > > Problem: > Following examples didn't work, because an internal reference to > copy-XML-structure is needed/forced. > > example 1: copy / modify > > declare function local:NodeAdd($XML, $XMLPath, $XMLValue) > { > > copy $XML2 := $XML > modify ( > insert node $XMLValue into $XML2/xml > ) > return > $XML2 > }; > > But: Instead of into $XML2/xml, > > into $XML/xml is needed, respectively into $XMLPath > > > Thanks a lot > Michael
