XQuery library module for updating XML in memory
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.
test Fix ordering issue with multiple insert-child calls #16 Apr 7, 2017
xray @ d1bea53 Fix ordering issue with multiple insert-child calls #16 Apr 7, 2017
.gitattributes added .gitattributes Sep 21, 2012
README.md Add replace-contents and clean up syntax use Apr 26, 2013
memory-operations-functional.xqy Throw an explicit error for passing nodes crossing document barriers #9 Apr 25, 2014
memory-operations-pure-xquery.xqy Fix ordering issue with multiple insert-child calls #16 Apr 7, 2017
memory-operations.xqy Fix ordering issue with multiple insert-child calls #16 Apr 7, 2017
mlpm.json Fix ordering issue with multiple insert-child calls #16 Apr 7, 2017
node-operations.xqy improve performance of outermost #11 Jun 19, 2014


XQuery XML Memory Operations

This module is created to provide an optimized way to perform operations on XML in memory. With heavy use XPath axis, node comparisions, and set operators this library is able to make changes to XML while only reconstructing nodes within the direct path of the nodes being altered. It also provides a way to perform multiple operations, while only reconstructiing the XML tree once.

The goal is to provide a way to bring the functionality of the XQuery Update Facility 1.0 (http://www.w3.org/TR/xquery-update-10/) to MarkLogic.

Advanced Transform Statements

By calling mem:copy($node as node()) as xs:string the following calls to mem operations are stored and not actually executed until mem:execute($transaction-id as xs:string) is called. This allows the document to be rebuilt only once and increases performance.

You can just perform a copy and execute that will provide a copy of the node free from ancestors.

Examples of this is as follows:

copy $c := fn:root($file)
modifiy (replace nodes $c/title with element title {"my new title"},
   	insert nodes attribute new-attribute {"my new attribute"} as last into
return $c
mem:copy(fn:root($file)) !
mem:replace(.,$file/title, element title {"my new title"}),
mem:insert-child(.,$file, attribute new-attribute {"my new attribute"}),

By using mem:copy and passing in a node, you indicating what the new root should be.

let $oldx := /a/b/x
   copy $newx := $oldx
   modify (rename node $newx as "newx", 
           replace value of node $newx with $newx * 2)
   return ($oldx, $newx)
let $oldx := /a/b/x
	mem:copy($oldx) ! 
	mem:rename(.,$oldx, fn:QName("","newx")),
	mem:replace-value(.,$oldx, $oldx * 5),

Other Operations

(: See http://www.w3.org/TR/xquery-update-10/#id-delete :)
(: See http://www.w3.org/TR/xquery-update-10/#id-insert :)
mem:insert-after($file/title, element new-sibling-after {"my new sibling element"} ),
mem:insert-before($file/title, element new-sibling-before {"my new sibling element"} ),
mem:insert-child($file, attribute new-attribute {"my new attribute"} ),
mem:insert-child-first($file, attribute new-attribute-2 {"my new attribute"} ),
(: See http://www.w3.org/TR/xquery-update-10/#id-rename :)
mem:rename($file//block, fn:QName('http://www.w3.org/1999/xhtml','p')),
(: See http://www.w3.org/TR/xquery-update-10/#id-replacing-node :)
mem:replace($file/title, element title {"my new title"} ),
(: See http://www.w3.org/TR/xquery-update-10/#id-replacing-node-value :)
mem:replace-value($file/title, "my new title" ),
(: Transform by using a function reference :)
mem:transform($title,function($node as node()) as node()* {element new-title {"This is so awesome!"}})