accessing previous context inside apply-templates?

[Mike Partridge]

Is it possible to access your caller's (not parent) context while inside a <xsl:template match...> or <xsl:for-each...>? Here is the xml I'm using:

<report-set>
...<report>
.....<detail-data>
.......<detail-column position="1" dsc="col1" sum_fg="0"/> .......<detail-column position="2" dsc="col2" sum_fg="1"/> .......<detail-column position="3" dsc="col3" sum_fg="1"/> .......<detail-column position="4" dsc="col4" sum_fg="1"/> .......<detail-column position="5" dsc="col5" sum_fg="1"/> .....</detail-data> .....<invoice inv_id="232243"> .......<break level="1"> .........<break level="2"> ...........<break level="3"> .............<detail> ...............<row> .................<field position="1">Text1</field> .................<field position="2">34</field> .................<field position="3">3400.00</field> .................<field position="4">0.00</field> .................<field position="5">3400.00</field> ...............</row> ...............<row> .................<field position="1">Text2</field> .................<field position="2">96</field> .................<field position="3">9600</field> .................<field position="4">0.00</field> .................<field position="5">9600.00</field> ...............</row> .............</detail> ...........</break> ...........<break level="3"> .............<detail> ...............<row> .................<field position="1">Text1</field> .................<field position="2">13</field> .................<field position="3">1300.00</field> .................<field position="4">-1300.00</field> .................<field position="5">0.00</field> ...............</row> ...............<row> .................<field position="1">Text2</field> .................<field position="2">13</field> .................<field position="3">2600</field> .................<field position="4">0.00</field> .................<field position="5">2600.00</field> ...............</row> .............</detail> ...........</break> .........</break> .......</break> .....</invoice> ...</report> </report-set>

When I am in the <break> context (of which there can be any number), I want to output a sum of each field based on the <detail-data> from the top. I've tried to apply-templates on the /report-set/report/detail-data/detail-column which can give me a column for each <detail-column>, but I need to sum from the context where the apply-templates was called. Is this possible? I've hacked a way by passing my context position and break level and going back to look for the break i want, but it's inefficient and hard to read, not to mention ugly.

Does anyone have any ideas? Please tell me there's an easier way!

Mike Partridge..

 

[Dimitre Novatchev]

Is it possible to access your caller's (not parent) context while inside a <xsl:template match...> or <xsl:for-each...>? Here is the xml I'm using:

<report-set>
..<report>
....<detail-data>
......<detail-column position="1" dsc="col1" sum_fg="0"/> ......<detail-column position="2" dsc="col2" sum_fg="1"/> ......<detail-column position="3" dsc="col3" sum_fg="1"/> ......<detail-column position="4" dsc="col4" sum_fg="1"/> ......<detail-column position="5" dsc="col5" sum_fg="1"/> ....</detail-data> ....<invoice inv_id="232243"> ......<break level="1"> ........<break level="2"> ..........<break level="3"> ............<detail> ..............<row> ................<field position="1">Text1</field> ................<field position="2">34</field> ................<field position="3">3400.00</field> ................<field position="4">0.00</field> ................<field position="5">3400.00</field> ..............</row> ..............<row> ................<field position="1">Text2</field> ................<field position="2">96</field> ................<field position="3">9600</field> ................<field position="4">0.00</field> ................<field position="5">9600.00</field> ..............</row> ............</detail> ..........</break> ..........<break level="3"> ............<detail> ..............<row> ................<field position="1">Text1</field> ................<field position="2">13</field> ................<field position="3">1300.00</field> ................<field position="4">-1300.00</field> ................<field position="5">0.00</field> ..............</row> ..............<row> ................<field position="1">Text2</field> ................<field position="2">13</field> ................<field position="3">2600</field> ................<field position="4">0.00</field> ................<field position="5">2600.00</field> ..............</row> ............</detail> ..........</break> ........</break> ......</break> ....</invoice> ..</report> </report-set>

When I am in the <break> context (of which there can be any number), I want to output a sum of each field based on the <detail-data> from the top. I've tried to apply-templates on the /report-set/report/detail-data/detail-column which can give me a column for each <detail-column>, but I need to sum from the context where the apply-templates was called. Is this possible? I've hacked a way by passing my context position and break level and going back to look for the break i want, but it's inefficient and hard to read, not to mention ugly.

Does anyone have any ideas? Please tell me there's an easier way!

Mike Partridge..

I am not sure what you exactly want, but if I guess well, this will answer your question.

This transformation:

<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xslutput method="text"/> <xsl:strip-space elements="*"/>

<xsl:key name="kDetail" match="detail-column" use="@position"/>

<xsl:template match="row">
<xsl:value-of select="sum(field[key('kDetail',
count(preceding-sibling::*)+1)/@sum_fg = 1])"/>
<xsl:text>
</xsl:text>
</xsl:template>
</xsl:stylesheet>

when applied on your source.xml:

<report-set>
<report>
<detail-data>
<detail-column position="1" dsc="col1" sum_fg="0"/>
<detail-column position="2" dsc="col2" sum_fg="1"/>
<detail-column position="3" dsc="col3" sum_fg="1"/>
<detail-column position="4" dsc="col4" sum_fg="1"/>
<detail-column position="5" dsc="col5" sum_fg="1"/>
</detail-data>
<invoice inv_id="232243">
<break level="1">
<break level="2">
<break level="3">
<detail>
<row>
<field position="1">Text1</field>
<field position="2">34</field>
<field position="3">3400.00</field>
<field position="4">0.00</field>
<field position="5">3400.00</field>
</row>
<row>
<field position="1">Text2</field>
<field position="2">96</field>
<field position="3">9600</field>
<field position="4">0.00</field>
<field position="5">9600.00</field>
</row>
</detail>
</break>
<break level="3">
<detail>
<row>
<field position="1">Text1</field>
<field position="2">13</field>
<field position="3">1300.00</field>
<field position="4">-1300.00</field>
<field position="5">0.00</field>
</row>
<row>
<field position="1">Text2</field>
<field position="2">13</field>
<field position="3">2600</field>
<field position="4">0.00</field>
<field position="5">2600.00</field>
</row>
</detail>
</break>
</break>
</break>
</invoice>
</report>
</report-set>

produces this output:

6834
19296
13
5213

In case my guess about the real meaning of your message was unsuccessful, could you, please, describe it in a correct and unambiguous way?

Dimitre Novatchev.
FXSL developer, XML Insider,

http://fxsl.sourceforge.net/ -- the home of FXSL
Resume: http://fxsl.sf.net/DNovatchev/Resume/Res.html

 

[Mike Partridge]

No, you guessed perfectly! Thanks so much for your help, and I'm sorry that my description was difficult to fathom. I see what you're doing, but can you clarify something? How is count(preceding-sibling::*)+1 different than position in this case? I have limited understanding of how to use axes, so please bear with me. If there are multiple <report> elements that need different sets of <detail-column>s in <report-set> (see example xml below), how can I reference the detail-column data from the current report only? If the xml structure was static I could back up through parent nodes, but I don't know how many <break>s there are so I can't hardcode the xpath. I have a feeling there is a relatively simple way to do this using the ancestor axis, but I'm not sure how. If I were to create a key as you defined it for the following example xml, they would conflict correct? That is why I think using the ancestor axis is the best way.

<report-set>
<report>
<detail-data>
<detail-column position="1" dsc="col1" sum_fg="0"/>
<detail-column position="2" dsc="col2" sum_fg="1"/>
<detail-column position="3" dsc="col3" sum_fg="1"/>
<detail-column position="4" dsc="col4" sum_fg="1"/>
<detail-column position="5" dsc="col5" sum_fg="1"/>
</detail-data>
<invoice inv_id="232243">
<break level="1">
<break level="2">
<break level="3">
...
</break>
</break>
</break>
</invoice>
</report>
<report>
<detail-data>
<detail-column position="1" dsc="name" sum_fg="0"/>
<detail-column position="2" dsc="description" sum_fg="0"/> <detail-column position="3" dsc="amount" sum_fg="1"/> </detail-data> <invoice inv_id="232244"> <break level="1"> <break level="2"> ... </break> </break> </invoice> </report> </report-set>

Thanks again for your help!

Mike Partridge

When I am in the <break> context (of which there can be any number), I want to output a sum of each field based on the <detail-data> from the top. I've tried to apply-templates on the /report-set/report/detail-data/detail-column which can give me a column for each <detail-column>, but I need to sum from the context where the apply-templates was called. Is this possible? I've hacked a way by passing my context position and break level and going back to look for the break i want, but it's inefficient and hard to read, not to mention ugly.

Does anyone have any ideas? Please tell me there's an easier way!

Mike Partridge..

I am not sure what you exactly want, but if I guess well, this will answer your question.

This transformation:

<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xslutput method="text"/> <xsl:strip-space elements="*"/>

<xsl:key name="kDetail" match="detail-column" use="@position"/>

<xsl:template match="row">
<xsl:value-of select="sum(field[key('kDetail',
count(preceding-sibling::*)+1)/@sum_fg = 1])"/>
<xsl:text>
</xsl:text>
</xsl:template>
</xsl:stylesheet>

when applied on your source.xml:
-- snip --

produces this output:

6834
19296
13
5213

In case my guess about the real meaning of your message was unsuccessful, could you, please, describe it in a correct and unambiguous way?

Dimitre Novatchev.
FXSL developer, XML Insider,

http://fxsl.sourceforge.net/ -- the home of FXSL
Resume: http://fxsl.sf.net/DNovatchev/Resume/Res.html

 

[Dimitre Novatchev]

No, you guessed perfectly! Thanks so much for your help, and I'm sorry that my description was difficult to fathom. I see what you're doing, but can you clarify something? How is count(preceding-sibling::*)+1 different than position in this case?

In this case using either of them will produce the same results.

I wanted somehow to express that there's no need for the "position" attribute on field elements and even that one can do without a position function.

There are other scenarios (e.g. when position is not used within a location step) , when position will only return the position of the current node in the current node-list -- this is *not* the same as count(preceding-sibling::*)+1 and depends on the way the xsl:apply-templates or the xsl:for-each were specified.

I have limited understanding of how to use axes, so please bear with me. If there are multiple <report> elements that need different sets of <detail-column>s in <report-set> (see example xml below), how can I reference the detail-column data from the current report only? If the xml structure was static I could back up through parent nodes, but I don't know how many <break>s there are so I can't hardcode the xpath. I have a feeling there is a relatively simple way to do this using the ancestor axis, but I'm not sure how. If I were to create a key as you defined it for the following example xml, they would conflict correct? That is why I think using the ancestor axis is the best way.

There's no problem -- just use:

ancestor::report[1]/detail-data

Dimitre Novatchev.
FXSL developer, XML Insider,

http://fxsl.sourceforge.net/ -- the home of FXSL
Resume: http://fxsl.sf.net/DNovatchev/Resume/Res.html