Building a FO document with FOP

["Ismaeil, Sameh Z" <sa...@eds.com>]

Hello All,

We are trying to build FO documents through Java code, these documents will
be rendered with FOP. I would like to know whether it is recommended to
build them using the FOP classes that represent FO elements (FONode/FObj and
its decendants), or whether it is better to build them as XML docuemnts and
use FOP for rendering only.

Thanks in advance

Re: Building a FO document with FOP

[David Penton <dj...@arrowsash.com>]

I'm chiming in late; you've probably already made your decision.

I have been doing lots of work generating fo through fop, and also XEP, 
with data extracted from a database.  I always use xsl stylesheets, but 
I do the entire process internally in java, except for the FOP run 
itself. There are several points in my processing flow which could be 
handled by writing data to intermediate files external to my java app, 
but I don't do it that way.  My flow is this:  I use jdbc, which feeds a 
java class that acts like an xml parser, and implements SAX2.  I create 
a JAXP SAXSource using this fake "parser" class, and using the JAXP API, 
I transform the incoming data in my java app using a reusable model of 
the transform (javax.xml.transform.Templates).  The result is serialized 
to disk as xsl-fo.

 Additionally, there ways other than JAXP; i.e. one can create compiled 
xslt stylesheets in java.

Because it is possible to do everything "inside java" using this 
approach, even it also uses xslt, my experience is that it is not easy 
to make a good case for generating xsl-fo directly. That is necessarily 
true, but the thing that should usually drive the choice is not, for 
example, whether you already have xml data as input to the whole 
process.  It is, I believe, more of a question of whether xslt is 
appropriate from an algorithmic point of view.  There are some things 
that are brutally difficult and inefficient to do using xslt.  If you 
have the kind of problem that is not particularly amenable to functional 
programming tree transformation solutions, maybe you need to create 
xsl-fo some other way in java.

Otherwise, the rapidity of development using java + xslt (in a way that 
is 'within java' anyway) is to good to pass up, at least for my database 
applications, and despite the fact that my input data is not xml.

- Dave P. -

Ismaeil, Sameh Z wrote:

>Hello All,
>
>We are trying to build FO documents through Java code,
>
<snip...>

>
>
>Thanks in advance
>
>