Digitally sign XML documents using PHP programming language and XAdES standard

We need some PHP code to add digital signature to XML documents. Please see the example document attached. (This is an example end product.) Near the beginning of file there is the \"\" tag. This is your input data as a string - what we already have. Please note that \"\" tag has different content each time. The thing missing is the ending tag: \"\". Your product is a well documented PHP code to do this task. Input data: \"\" tag as a string variable; Output data: \"\" tag.