Is it possible to modify a source node using XSLT?

[titanandrews]

Hi,

I have ran into a situation that I think should be possible, but I am
fairly new to XSLT so maybe not.

Suppose I have the following document
<ROOT>
<FOO name="A">
<CHILD name="B"/>
</FOO>
</ROOT>

I am creating a new XML doc using XSLT, and I change the name attribute
of the first node FOO in my target doc. The name attribute of CHILD is
dependent on it's parent, i.e. it's built from the parent name. So I
select the parent name with XPATH "../@Name", but it returns the name
from the source document. I need the name from the target document,
because the old name is no good. How can I do this? Is it possible to
modify a source node in XSLT? I can modify a DOM document in a program
easily, so it seems like it would be possible to do in XSLT. If I can
do this, then the task will be easy. Are there any other ways to
achieve this?


Many thanks for the help!


regards,

B

 

[David Carlisle]

Hi,

I have ran into a situation that I think should be possible, but I am
fairly new to XSLT so maybe not.

Suppose I have the following document
<ROOT>
<FOO name="A">
<CHILD name="B"/>
</FOO>
</ROOT>

I am creating a new XML doc using XSLT, and I change the name attribute
of the first node FOO in my target doc. The name attribute of CHILD is
dependent on it's parent, i.e. it's built from the parent name. So I
select the parent name with XPATH "../@Name", but it returns the name
from the source document. I need the name from the target document,
because the old name is no good. How can I do this? Is it possible to
modify a source node in XSLT? I can modify a DOM document in a program
easily, so it seems like it would be possible to do in XSLT. If I can
do this, then the task will be easy. Are there any other ways to
achieve this?


Many thanks for the help!


regards,

B

XSLT input tree is read only, however as far as I understand your
description you don't want to modify the source just generate a new
element with some name. You haven't given any indication of what element
name you need to generate. Also it needs to be @name not @Name, XML is
case sensitive.

What result document do you need to generate given the above input??

David

 

[Barry Andrews]

Hi,

So the source is read only? That is good to know I suppose, although
it seems odd to me. Anyway, let me try to explain a little more. My
target document might look like this:

<TARGET>
<FI name="Changed">
<CHILD_FI name="Changed_1"/>
</FI>
</TARGET>

Notice that CHILD_FI name is based on FI. (with _1 appended) But I
cannot do this, because when I select the name from the parent, I get
the old name which is A. So instead my new name would end up being A_1,
which is not what I want.
Make sense?

many thanks,

B

 

[David Carlisle]

Hi,

So the source is read only? That is good to know I suppose, although
it seems odd to me. Anyway,

It would be very hard to define any behaviour to an xslt transformation
if the input could change during a transformation. There is no
requirement on a processor to process any templates in any particular
order, only that the results are combined into the final result tree as
specified, so if templates could alter the input, the behaviour of every
stylesheet would be undefined, as the input to each template would
depend on implementation-specific choices of the order of template
execution.

This is the usual behaviour of any declarative/functional language.
If you evaluate a function f(x,y) a result is returned but there are no
side effects, in particular the inputs to a unction are never changed.

let me try to explain a little more. My
target document might look like this:

<TARGET>
<FI name="Changed">
<CHILD_FI name="Changed_1"/>
</FI>
</TARGET>

Notice that CHILD_FI name is based on FI. (with _1 appended) But I
cannot do this, because when I select the name from the parent, I get
the old name which is A. So instead my new name would end up being A_1,
which is not what I want.
Make sense?

In a typical transformation the names of the result elements bear no
relation at all to the names of the input elements. Think of converting
docbook to html, or html to SVG or ... When generating the name of any
element in the result you have access via xpath to any part of the
source, so any information that caused you to generate the name FI on
the parent element is available still so there is nothing to stop you
generating an element name that contains the string _FI. However you
haven't given any indication of the transformation that you are trying
to so I can't offer any code.

David

 

[Barry Andrews]

Thanks for the response!

You have answered my question about modifying the source very well.

I will try to post my XSLT code tomorrow when I get to work. It will
probably help explain what I am trying to do.


thanks,

B