How to generate a blank table cell in XSL? - xslt

Question

why does the table cell disappear when there is no photo existing to generate?
i am using the following code which is not working. What do i need to change if i want to generate a blank table cell if there is no photo existing to generate?
<xsl:for-each select="...............">
<xsl:choose>
<xsl:when test="*">
<xsl:if test=".....">
<xsl:if test=".......">
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
<fo:block>
<fo:external-graphic src="url('{concat($FILEPATH,.....'])}')"
inline-progression-dimension.maximum="4.1cm" block-progression-dimension.maximum="4cm"
content-width="scale-to-fit" content-height= "scale-to-fit" scaling="uniform"/>
</fo:block>
</fo:table-cell>
</xsl:if>
</xsl:if>
</xsl:when>
<xsl:otherwise>
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
<fo:block>
<fo:leader/>
</fo:block>
</fo:table-cell>
</xsl:otherwise>
</xsl:choose>
</xsl:for-each>

Answer 1

Your have <xsl:when test="*"> ... is that node empty? If that is your outside test and passes, but the other IFs (you do not show) do not pass their test, your template yields nothing.
Breaking this down with comments:
<xsl:when test="*">
<xsl:if test=".....">
<!-- If this does not pass, you get nothing -->
<xsl:if test=".......">
<!-- If this does not pass, you get nothing -->
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
<fo:block>
<fo:external-graphic src="url('{concat($FILEPATH,.....'])}')"
inline-progression-dimension.maximum="4.1cm" block-progression-dimension.maximum="4cm"
content-width="scale-to-fit" content-height= "scale-to-fit" scaling="uniform"/>
</fo:block>
</fo:table-cell>
</xsl:if>
</xsl:if>
</xsl:when>
<xsl:otherwise>
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
<fo:block>
<fo:leader/>
</fo:block>
</fo:table-cell>
</xsl:otherwise>

Answer 2

Kevin is right, given your example, your when clause is likely satisfied but if one of your if statements evaluates as false, you will get an empty table-cell. My advice is to add the conditions of your if statements to the when clause using logic operators such as AND/OR, for example, say the conditions in your template where like this...
<xsl:when test="$node = 'A'">
<xsl:if test="$node/child = 'B'">
<xsl:if test="not(contains($node/child,'C'))">
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
...
</fo:table-cell>
</xsl:if>
</xsl:if>
</xsl:when>
<xsl:otherwise>
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
<fo:block>
<fo:leader/>
</fo:block>
</fo:table-cell>
</xsl:otherwise>
</xsl:choose>
Could be expressed as
<xsl:when test="$node = 'A' AND $node/child = 'B' AND not(contains($node/child,'C'))">
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
...
</fo:table-cell>
</xsl:when>
<xsl:otherwise>
<fo:table-cell border="solid" text-align="center" font-weight="bold" number-columns-spanned="1">
<fo:block>
<fo:leader/>
</fo:block>
</fo:table-cell>
</xsl:otherwise>
</xsl:choose>
And in doing so, you will make sure that if any of those three logical conditions aren't met, that your otherwise block will be called and the leader should keep the cell from collapsing, rather than the when statement being called despite the fact that your logic conditions aren't technically satisfied, and winding up with an empty cell which will be collapsed by FOP by default. Hope this clears things up a bit for you.