Need to build a general sequence of integers

mphare · February 16th, 2009, 11:46 AM

Hi,

I'm using Saxon9b

I have need to perform a task similar to: for i = 1 to n
and do some work with each value of i

the value n is to be derived from TL1Position data in my XML file. There are multiple TL1Positions, I need the one with the largest value:

Code:

<xsl:variable name="n">
                    <xsl:value-of select="max($repoSection//ratttable/rattrow//TL1Position[ancestor::rattrow//TL1Block = 2])"></xsl:value-of>
                    </xsl:variable>

$n is being set to a number such as 5 or 10 as I expected, but when I've tried using $n the for operator:

for $i in 1 to $n return $i

I get an error

Code:

$ ./buildNMIS TEST
Building NMIS from Repository / Implementation
Target AID Type: TEST
Repository Dir: ../Repository
Implementation Dir: ../Implementation
Validation error at xsl:value-of on line 890 of file:/d:/mphare/SWTools/Projects/RepositoryPOCs/NMIRepoPOC/Scripts/GenNMIS.xsl:
  FORG0001: Cannot convert zero-length string to an integer
Transformation failed: Run-time errors were reported

If I set $n to a constant

Code:

<xsl:variable name="n" select="5"></xsl:variable>

It works fine.

What is max() returning if it's not a constant value (or at least something that can be used as a constant in this manner)?

Thanks

Martin Honnen · February 16th, 2009, 12:03 PM

Does it work with

Code:

<xsl:variable name="n" select="max($repoSection//ratttable/rattrow//TL1Position[ancestor::rattrow//TL1Block = 2])"/>

?
If not then you need to show the relevant XML input, max() only returns an empty sequence I think if the input sequence is empty.

mhkay · February 16th, 2009, 12:14 PM

I suspect that the path expression used as the argument to max() is selecting nothing. But even if it selecting something, you will need to convert the value to an integer, which you can do using the constructor function xs:integer()

mphare · February 16th, 2009, 12:15 PM

Hi Martin,

That was the first thing I thought of.

If I remove the 'for' statement (so it compiles) and output the value of $n,

Code:

<xsl:text>Max Position : </xsl:text>
<xsl:variable name="maxPos">
<xsl:value-of select="max($repoSection//ratttable/rattrow//TL1Position[ancestor::rattrow//TL1Block = 2])"></xsl:value-of>
</xsl:variable>
                    
<xsl:value-of select="$maxPos"></xsl:value-of>

I get

Code:

<SyntaxContainer>
<SyntaxHeading/>
<Syntax>ED-TEST:[&lt;TID&gt;]:Max Position: 1&lt;P1-1&gt;:&lt;CTAG&gt;:Max Position :
3[&lt;P2-1&gt;],[&lt;P2-2&gt;]:[&lt;P3-1&gt;],[&lt;P3-2&gt;]:[&lt;KEYWORD=DOMAIN&gt;]:,[&lt;P5-3&gt;];</Syntax>
</SyntaxContainer>

Notice the Max Positions in the output. I'm getting 1 and 3, which are the values I expect to be getting.

Here's a fragment of the input XML. It's part of a large table (ratttable) in a collection ($repoSection). There is only one ratttable in this repoSection. There can be any number of rattrows that have TL1Block=2 each with their own TL1Position value, could be repeated, could be missing values (such as 1 and 3, but no 2 as shown below)

Code:

<rattrow attrfield = "4">
<rattcell format = "Small" colname = "1"><TL1Instance>0001</TL1Instance></rattcell>
<rattcell format = "Small" colname = "2"><TL1Attribute attrType = "Positional">P2-1</TL1Attribute></rattcell>
<rattcell format = "Small" colname = "3"><TL1Domain>&lt;IPv4></TL1Domain></rattcell>
<rattcell format = "Small" colname = "4"><TL1Default></TL1Default></rattcell>
<rattcell format = "Tight" colname = "5"><TL1Commands cmdType = "Create">Y</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "6"><TL1Commands cmdType = "Modify">Y</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "7"><TL1Commands cmdType = "Delete">N</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "8"><TL1Commands cmdType = "RetrieveIn">M</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "9"><TL1Commands cmdType = "RetrieveOut">N</TL1Commands></rattcell>
<rattcell format = "Small" colname = "10"></rattcell>
<rattcell format = "Small" colname = "11"><TL1Block>2</TL1Block></rattcell>
<rattcell format = "Small" colname = "12"><TL1Position>1</TL1Position></rattcell>
<rattcell format = "Small" colname = "13"><RespTL1Block>0</RespTL1Block></rattcell>
<rattcell format = "Small" colname = "14"><RespTL1Position>0</RespTL1Position></rattcell>
</rattrow>
<rattrow attrfield = "4">
<rattcell format = "Small" colname = "1"><TL1Instance>0001</TL1Instance></rattcell>
<rattcell format = "Small" colname = "2"><TL1Attribute attrType = "Positional">P2-2</TL1Attribute></rattcell>
<rattcell format = "Small" colname = "3"><TL1Domain>N|Y</TL1Domain></rattcell>
<rattcell format = "Small" colname = "4"><TL1Default>N</TL1Default></rattcell>
<rattcell format = "Tight" colname = "5"><TL1Commands cmdType = "Create">Y</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "6"><TL1Commands cmdType = "Modify">Y</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "7"><TL1Commands cmdType = "Delete">N</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "8"><TL1Commands cmdType = "RetrieveIn">Y</TL1Commands></rattcell>
<rattcell format = "Tight" colname = "9"><TL1Commands cmdType = "RetrieveOut">N</TL1Commands></rattcell>
<rattcell format = "Small" colname = "10"></rattcell>
<rattcell format = "Small" colname = "11"><TL1Block>2</TL1Block></rattcell>
<rattcell format = "Small" colname = "12"><TL1Position>3</TL1Position></rattcell>
<rattcell format = "Small" colname = "13"><RespTL1Block>0</RespTL1Block></rattcell>
<rattcell format = "Small" colname = "14"><RespTL1Position>0</RespTL1Position></rattcell>
</rattrow>

Thanks for taking a look!

mphare · February 16th, 2009, 12:58 PM

Hi Michael,

I've added xs:integer into the constructor, now I get an error that it can't convert an empty string.

So, the max() statement isn't selecting anything.

In that case, I'm not sure how it's outputting the 3 as in 'Max Position : 3' in the above output example.

I'm obviously missing something fundamental.

Martin Honnen · February 16th, 2009, 01:22 PM

I am not able to find the problem in those snippets you have posted. Try to isolate the problem to a small but complete test case, then if that does not help to find the problem yourself, post that test case here.

mphare · February 16th, 2009, 03:36 PM

I tried a slightly different route to solve the problem.

Code:

                    <xsl:variable name="rattRows">
                        <xsl:for-each select="$repoSection//ratttable/rattrow[.//TL1Block = 2]">
                            <xsl:sort select=".//TL1Position"/>
                                <ROW>
                                    <xsl:value-of select=".//TL1Position"/>
                                </ROW>
                        </xsl:for-each>
                    </xsl:variable>
                    
                    
                    

                    <xsl:variable name="maxPos" as="xs:integer">
                        <xsl:value-of select="$rattRows//ROW[last()]"></xsl:value-of>
                    </xsl:variable>
                    
                    
                    
                    
                    <xsl:value-of select="$maxPos"></xsl:value-of>

But my results are the same. All indications are the table search is returning nothing and the convert with xs:integer is failing.

Code:

$ ./buildNMIS TEST
Building NMIS from Repository / Implementation
Target AID Type: TEST
Repository Dir: ../Repository
Implementation Dir: ../Implementation
Validation error at xsl:value-of on line 902 of file:/d:/mphare/SWTools/Projects/RepositoryPOCs/NMIRepoPOC/Scripts/GenNMIS.xsl:
  FORG0001: Cannot convert zero-length string to an integer
Transformation failed: Run-time errors were reported

Yet, if I remove the xs:integer, the value of 3 is written to the result.

Code:

                    <SyntaxContainer>
                        <SyntaxHeading/>
                        <Syntax>ED-TEST:[&lt;TID&gt;]:Max Position:
                            1&lt;P1-1&gt;:&lt;CTAG&gt;:3[&lt;P2-1&gt;],[&lt;P2-2&gt;]:[&lt;P3-1&gt;],[&lt;P3-2&gt;]:[&lt;KEYWORD=DOMAIN&gt;]:,[&lt;P5-3&gt;];</Syntax>
                    </SyntaxContainer>

Is 3 not a string?

mphare · February 17th, 2009, 11:01 AM

Hi Martin,

I did as you suggested:

Code:

<?xml version="1.0" encoding="UTF-8"?>
<Root>
    <Chapter>
        <Section>
            <Table>
                <Row>
                    <Block>1</Block>
                    <Position>1</Position>
                </Row>
                <Row>
                    <Block>1</Block>
                    <Position>2</Position>
                </Row>
                <Row>
                    <Block>1</Block>
                    <Position>3</Position>
                </Row>
                <Row>
                    <Block>2</Block>
                    <Position>1</Position>
                </Row>
                <Row>
                    <Block>2</Block>
                    <Position>5</Position>
                </Row>
                <Row>
                    <Block>2</Block>
                    <Position>3</Position>
                </Row>
                <Row>
                    <Block>2</Block>
                    <Position>4</Position>
                </Row>
                <Row>
                    <Block>3</Block>
                    <Position>1</Position>
                </Row>
                <Row>
                    <Block>3</Block>
                    <Position>2</Position>
                </Row>
                <Row>
                    <Block>3</Block>
                    <Position>3</Position>
                </Row>
            </Table>
        </Section>
    </Chapter>
</Root>

Code:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">

    <xsl:output indent="yes" method="xml" version="1.1"/>

    <xsl:variable name="implSubTree" select="collection(concat('.','/?select=*.xml'))"/>

    <!--
        =========================================================
    -->
    <xsl:template match="/">
        <xsl:apply-templates select="$implSubTree//Section"/>
    </xsl:template>


    <!-- 
        =========================================================
    -->
    <xsl:template match="Section">

        <xsl:variable name="Section" select="."/>
        <xsl:variable name="Block" select="2"/>

        <xsl:variable name="maxPos">
            <xsl:value-of select="max($Section//Row/Position[ancestor::Row/Block=$Block])"/>
        </xsl:variable>

        <xsl:text>&#x0a;</xsl:text>
        <xsl:text>Block: </xsl:text>
        <xsl:value-of select="$Block"/>
        <xsl:text>&#x0a;</xsl:text>
        <xsl:text>Max Pos: </xsl:text>
        <xsl:value-of select="$maxPos"/>

        <xsl:for-each select="1 to $maxPos">
            <xsl:text>&#x0a;</xsl:text>
            <xsl:text>Seq: </xsl:text>
            <xsl:value-of select="."/>
        </xsl:for-each>

    </xsl:template>

</xsl:stylesheet>

It works like a charm.
Does exactly what I needed.
So I'm pretty sure my logic is sound, it must me something to do with the data I'm feeding the script.

mphare · February 17th, 2009, 11:32 AM

Found It!

The line:

$repoSection//ratttable/rattrow//TL1Position[.//TL1Block = 2]

is incorrect per my data structure.

It should have been:

$repoSection//ratttable//rattrow//TL1Position[.//TL1Block = 2]

Thanks for all the help!