Output of PDF report based on (custom, hand-coded) XSL-FO

Question

I am attempting to reproduce a fairly particular report format using the XSL-FO "option" in ORACLE APEX. I am operating on our client's machine (which is APEX 3.1 and Oracle 10 something), but receive similar results under the hosted apex.oracle.com environment (APEX 4, BI, etc.). I presume (but currently can't verify) they have the Oracle BI set up as their print server (simple XSL-FO, RTF all seem to work).
I have been using the Oracle BI Publisher Desktop template viewer tool to process my XML/XSL-FO into PDF, and it looks and works great!; I see an almost exact reproduction of their "old" report.
However, when I upload the XSL to APEX, I get a PDF with 0 bytes (error somewhere). I have tried to reduce the XSL to the point where I get an error and I will try to explain what works and what doesn't:
1. Goto APEX -> Application -> Shared Components -> Report Layouts -> Create and Create new Generic XSL-FO report.
2. Copy the text in "Page Template" to new (empty) text document [in Notepad++].
3. Upload to APEX as new Name Columns (XSL-FO) layout.
-- Still Works --
4. Changed page size to letter format (612pt x 792pt) and modified margins to 10pt all-around.
-- Still Works --
5. Insert text (within <fo:block> and <fo:inline> elements) into header.
6. Add a table:
                         <fo:table xsl:use-attribute-sets="border" margin-top='10pt' width='100%'>
                              <xsl:variable name="_XDOFOPOS2" select="number(1)"/>
                              <xsl:variable name="_XDOFOTOTAL" select="number(1)"/>
                              <fo:table-column column-width="40%"/>
                              <fo:table-column column-width="60%"/>
                              <fo:table-body>
                                   <fo:table-row >
                                        <fo:table-cell padding-top='20pt'> <fo:block text-align='right' > <fo:inline> Inspected By: </fo:inline> </fo:block> </fo:table-cell>
                                        <fo:table-cell> <fo:block text-align='left' > <fo:inline> <xsl:value-of select='.//INSPECTOR' /> </fo:inline> </fo:block> </fo:table-cell>
                                   </fo:table-row>
                                   <fo:table-row >
                                        <fo:table-cell> <fo:block text-align='right' > <fo:inline> Approved By: </fo:inline> </fo:block> </fo:table-cell>
                                        <fo:table-cell> <fo:block text-align='left' > <fo:inline> <xsl:value-of select='.//APPROVAL' /> </fo:inline> </fo:block> </fo:table-cell>
                                   </fo:table-row>
                                   <fo:table-row>
                                        <fo:table-cell> <fo:block text-align='right' > <fo:inline> Date Approved: </fo:inline> </fo:block> </fo:table-cell>
                                        <fo:table-cell padding-bottom='20pt'> <fo:block text-align='left' > <fo:inline> <xsl:value-of select='.//APPROVALDATE' /> </fo:inline> </fo:block> </fo:table-cell>
                                   </fo:table-row>
                              </fo:table-body>
                         </fo:table>
STOPS WORKING
My query is: SELECT * FROM Inspections
and all of the fields referred to above exist.
Does anyone know how to find out what the internal server is choking on, or is there some problem with my process, or?
Thanks kindly,
Daniel

Answer 1

I would like to post what I did in fact get to work.
I took the suggestion to replace single-quotes with double-quotes. What also DID seem to help things was:
1. removing all XML entities from my markup, even properly escaped ones (like &amp; or &#160;)
2. ensuring that:
<xsl:variable name="_XDOFOPOS2" select="number(1)"/>
<xsl:variable name="_XDOFOTOTAL" select="number(1)"/>
appeared in the table (before anything else, still not sure what these are controlling or internal Oracle logic is happening).
I am still not 100% (or even 60%) sure this problem won't crop up if we have to modify our template, but through going through our original markup and adding it to a file that "works", table by table, and
assessing any errors, our reporting now works.
However, having entities (especially ampersand, or the non-breaking space [used as a placeholder for NULL database values to ensure the table-cell gets created]) would be useful.
Thanks for your comments.
Daniel