[Cxml-devel] how to create tags with SAX to make an almost identity transformation

[Russ Tyndall]

Howdy,

You will need to issue sax:start-element and sax:end-element calls 
instead of doing a string replace.Essentially you will replace the 
single sax:characters call with a series of characters / elements calls.

EG:
(defclass preproc (cxml:sax-proxy) ())

(defmethod sax:characters ((handler preproc) data)
   (let ((chunks (cl-ppcre:split "\\|" data)))
     (if (= 1 (length chunks))
         (call-next-method)
         (loop for c in chunks
               for first? = t then nil
               do (unless first?
                    (sax:start-element handler nil nil "bar" nil)
                    (sax:end-element handler nil nil "bar"))
                  (sax:characters handler c)))))

(cxml:parse "<test>content | ola</test>"
   (make-instance 'preproc
    :chained-handler (cxml:make-string-sink)))
=>
"<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<test>content <bar/> ola</test>"


Hope this helps,
Russ Tyndall
Acceleration.net

On 11/03/2014 07:47 AM, Alexandre Rademaker wrote:
> Hi,
>
> I need to transform all characters | to tags <bar/> in all texts blocks of a big XML file. That is, whenever I found
>
> <test att="one|two">content | something more | and done</test>
>
> I need to transform to
>
> <test att="one|two">content <bar/> something more <bar/> and done</test>
>
> Note that | can also occur in attributes values and, in that case, they must be keeped unchanged. Reading the slide http://common-lisp.net/project/cxml/saxoverview/pages/11.html I wrote
>
> ===
> (defclass preproc (cxml:sax-proxy) ())
>
> (defmethod sax:characters ((handler preproc) data)
>    (call-next-method handler (cl-ppcre:regex-replace "\\|" data "<bar/>")))
> ===
>
> But of course, it produces a string (escaped) not a tag in the final XML.
>
> WML> (cxml:parse "<test>content | ola</test>"
>                       (make-instance 'preproc
>                                      :chained-handler (cxml:make-string-sink)))
> "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
> <test>content <bar/> ola</test>"
>
> Any idea or directions?
>
> Best,
>
> ----
> Alexandre Rademaker
> http://arademaker.github.com
>
>
>
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