libxml2 XPATH - Selecting subset of data from XML - c++

I am fairly new to XML dev.. I had a few questions regarding XML parsing with XPATH and libxml.
I have an XML structured as :
<resultset>
<result count=1>
<row>
<name> He-Man! </name>
<home> Greyskull </home>
<row>
</result>
<result count=2>
<row>
<name> Spider-Man</name>
<home> Some downtown apartment </home>
<row>
<row>
<name> Disco-Man!</name>
<home> The 70's dance floor </home>
<row>
</result>
<resultset>
I need to pick out the names from this XML , but where the count is 2 , i need it only from the first record. I ran through a few tutorials, but i am unable to come up with an XPATH query which would serve this purpose.
/name will select all name elements.
/result[#count > 1 ]/row[1]/name | /result[#count =1 ]/row/name
Is this possible to be done with XPATH ? Is this better to be done via XPATH or by walking the XML tree?
Can some one point me to some complex searches through out XML's ?
Edit : The actual scenario requires select a subset of the XML row , which are nested at 2 levels at times. This sounds like i need to OR '|' many paths to select the nodes i require... I am not sure if that would be efficient as opposed to walking a tree... The above is typed to replicate the problem :)
Thanks!

Try this XPath -
/resultset/result[#count=2]/row/name
This will give a list of all nodes falling under this XPath. From this just take the first element (as you needed only the first record).

I'd probably keep my xpath simpler and just extract both cases, then loop over both node sets.
If you do need to go down the single xpath route, you should try out your xpath expressions in something that lets you enter them live, rather than having to recompile C/C++ code. You should be able to do that by loading your XML into firefox and using firebug - for example typing $x('//name') in the firebug console gives three nodes.
NOTE however that your XML is invalid... You have a bunch of "<row>"s that should be "</row>" and the same for "<resultset>" and your counts need to be
<result count="1">
i.e. with quote marks around the value.

Related

pre-processing script to switch product codes

I have a snippet of code I've inherited and I'm trying to get it to work on multiples of the match pattern and set a tag from looking up a value from a table using another tag. What happens is that, for every item, the same lookup is performed and not the relative one for the node. I can't work out the syntax to work thru all entries and substitute the correct one. It's got to be simple it's just that I am simpler :)
My source xml contains this (within an outer /oomsdoc document node not shown):
<item>
<lineqty> 1</lineqty>
<linesku>BNLP5008 </linesku>
<linecustprod>xxxxxxxxxxxxxxx</linecustprod>
<linedesc>London Pride (Bot500mlx8) </linedesc>
</item>
<item>
<lineqty> 1</lineqty>
<linesku>BNBL5008 </linesku>
<linecustprod>xxxxxxxxxxxxxxx</linecustprod>
<linedesc>Bengal Lancer (Bot500mlx8) </linedesc>
</item>
I want to substitute the xxxxxxxxxxxxxxx in each linecustprod tag with the material from the lookup table using the value of the linesku tag.
This is my lookup table:
<Materials>
<product sku='BNLP5008 ' material='LONDON PRIDE'/>
<product sku='BNBL5008 ' material='BENGAL LANCER'/>
</Materials>
and this is my xslt code.
<xsl:variable name="SkuList" select="document('d:\test\transforms\catalogue.xml')/Materials"/>
<xsl:template match="/oomsdoc/item/linecustprod">
<xsl:variable name="MySku" select="/oomsdoc/item/linesku"/>
<linecustprod>
<xsl:value-of select="$SkuList/product[#sku=$MySku]/#material"/>
</linecustprod>
</xsl:template>
I'm guessing some kind of xsl foreach would work but just can't find a usable example to crib :)
Your guidance again would be appreciated at this point in my frustration :)
Thanks,
Brian.
Changing the variable definition to
<xsl:variable name="MySku" select="../linesku"/>
should be sufficient, this will pull out the linesku that is a sibling to the linecustprod you're currently looking at. As currently defined the variable will contain a node set of all the linesku elements in the document, so the value-of will give you the first entry from $SkuList that matches any entry in the main input file.
In addition to Ian Roberts' answer, please change
<xsl:variable name="SkuList" select="document('d:\test\transforms\catalogue.xml')/Materials"/>
to
<xsl:variable name="SkuList" select="document('/d:\test\transforms\catalogue.xml')/Materials"/>
for some reason, the first throws an error (malformed URL).

Refer to specific cell in xslt import/export filter for Calc

I am using xslt filter for importing/exporting data from Calc worksheet. Is it possible to refer to a specific cell address ? For example, if we want to export data from cell B2, how do we refer to this cell address in export xslt ?
Without knowing much about Openoffice or their xslt filter function, I can tell you that you're probably going to need a fairly simple XPath to reference a specific Cell's data - I doubt it would be as simple as calling getCell('B2') unless they have provided you with some custom xslt functions (I'm assuming they've put you in a raw XSLT environment).
Anyway, I think this question may be more about XSLT and xpath, than it is about openoffice. With that in mind, I'm going to fashion my own sample xml and examples and hopefully that will be enough to get you started.
For an input xml that looks something like this:
<ooo_calc_export>
<ooo_sheet num="1" name="sheet1">
<ooo_row num="2">
<fisrtCell>Oh</firstCell>
<secondCell>Hai</secondCell>
<thirdCell>There</thirdCell>
</ooo_row>
<ooo_row num="3">
<fisrtCell>Oh</firstCell>
<secondCell>Hello</secondCell>
<thirdCell>Back!</thirdCell>
</ooo_row>
</ooo_sheet>
</ooo_calc_export>
An absolute XPath to access cell B2's data would look like this ooo_calc_export/ooo_sheet/ooo_row[#num='2']/secondCell/text()
But the above is an absolute path and in XSLT, we would often author relative xpaths as we are in the midst of processing a document. Imagine you're in a template which matches on the ooo_calc_export node and you wanted to store Cell B2's data in a variable for later use. Consider this example:
<xsl:template match="/ooo_calc_export">
<!-- a relative xpath does not being with a forward slash -->
<xsl:variable name="B2" select="ooo_sheet/ooo_row[#num='2']/secondCell/text()" />
</xsl:template>
Now lets imagine you wanted a template to match on the cell B2 node itself:
<xsl:template match="ooo_row[#num='2']/secondCell">
<!-- a relative xpath does not being with a forward slash -->
<xsl:variable name="B2_text" select="text()" />
</xsl:template>
This is a good tutorial on XSLT to get you started. Also, the W3 Schools references on XPath and XSLT aren't the worst.

xsl - select node by child

I have a problem selecting just elements of an xml, which contain a specific child node. Asumme the following part of an xml:
<root>
<Navision.Buchungen>
<Saldo>-110867.7500</Saldo>
<Navision.Kontostruktur>
<Bereich>1</Bereich>
</Navision.Kontostruktur>
</Navision.Buchungen>
<Navision.Buchungen>
<Saldo>-3082585.2100</Saldo>
<Navision.Kontostruktur>
<Bereich>2</Bereich>
</Navision.Kontostruktur>
</Navision.Buchungen>
...
</root>
Now I have an xsl part like this to get the sum of 'Saldo':
<xsl:variable name="FACT0" select="sum(//root/Navision.Buchungen/Saldo)"/>
But how can I select just the Saldo for 'Bereich' 1 for example?
Use this XPath:
//root/Navision.Buchungen[Navision.Kontostruktur/Bereich = 1]/Saldo
//root/Navision.Buchungen[Navision.Kontostruktur/Bereich = 1]/Saldo
Edited:
oh already posted.
For further problems you can use one of the online testbeds like this one. And of course good manuals like those from w3schools, also with testbeds for xsl

XSL: Combining grouping and call-template

I've read with interest the techniques available on the web to extract a unique list of items from a XML file containing duplicates using XSL.
These range into 2 categories:
1) The Muenchian method (example: http://www.jenitennison.com/xslt/grouping/)
2) Or the previous-sibling look-up
These both rely on an XPath expression to select the data to group by.
However, in the XML file that I'm trying to work out, the data is not present "natively" in the XML file. I am using a xsl:template to compute some aggregated data from my elements. And I would like to group based on the aggregated data.
For example I have:
<filmsreview>
<record><data name='movie'>Star Wars</data><data name='ratings'>John:Good, Mary:Good</data></record>
<record><data name='movie'>Indiana Jones</data><data name='ratings'>John:Good, Mary:Bad, Helen:Average</data></record>
<record><data name='movie'>Titanic</data><data name='ratings'>John:Bad, Helen:Good</data></record>
</filmsreview>
I know that the structuration of data is not perfect and that by creating sub-elements I could do something easier, but I cannot change the data source easily, so let's take this as a challenge.
And I would like to build a recap where I have John's distinct ratings:
John's ratings:
Good
Bad
I have a xsl:template that can take a record element and return John's rating for this record:
Example:
<xsl:template name="get_rating">
<xsl:param name="reviewer" />
<!-- I use some string manipulation, and xsl:value-of to return the review for John-->
</xsl:template>
I can just call it under a xsl:for-each to get the exhaustive list of John's review. But I cannot combine this call with any of the methods to get unique values.
Do I have to use an intermediary XSL to convert my XML file to a more structured way? Or can I do in a single step?
Many thanks
Gerard
Hmm... This should be possible using xslt variables and the nodeset method, perhaps something like this:
<xsl:variable name="_johnsRatings">
<xsl:apply-templates select="/" mode="johnsRatings" />
</xsl:variable>
<xsl:variable name="johnsRatings" select="msxsl:node-set($_johnsRatings)" />
<xsl:template match="/" mode="johnsRatings">
<Ratings>
<xsl:for-each select="/filmsReview/record/data[#name='ratings']">
<Rating><xsl:call-template name="get_rating" /></Rating>
</xsl:for-each>
</Ratings>
</xsl:template>
At this point, it should be possible to query the $johnsRatings variable using standard XPath queries, and you can use either of the two methods you mentioned above to retrieve unique values from it...
Hope that helps
EDIT:
I don't know what XSLT engine you are using, I assumed you have access to the msxsl:node-set() function. However, most XSLT processors have similar methods, so you might have to search around for an equivalent method in your processor

Ignore name space with t: prefix

We have XML file like below...
<?xml version='1.0'?>
<T0020 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.safersys.org/namespaces/T0020V1 T0020V1.xsd"
xmlns="http://www.safersys.org/namespaces/T0020V1">
<IRP_ACCOUNT>
<IRP_CARRIER_ID_NUMBER>1213561</IRP_CARRIER_ID_NUMBER>
<IRP_BASE_COUNTRY>US</IRP_BASE_COUNTRY>
<IRP_BASE_STATE>AL</IRP_BASE_STATE>
<IRP_ACCOUNT_NUMBER>15485</IRP_ACCOUNT_NUMBER>
<IRP_ACCOUNT_TYPE>I</IRP_ACCOUNT_TYPE>
<IRP_STATUS_CODE>0</IRP_STATUS_CODE>
<IRP_STATUS_DATE>2004-02-23</IRP_STATUS_DATE>
<IRP_UPDATE_DATE>2007-03-09</IRP_UPDATE_DATE>
<IRP_NAME>
<NAME_TYPE>LG</NAME_TYPE>
<NAME>WILLIAMS TODD</NAME>
<IRP_ADDRESS>
<ADDRESS_TYPE>MA</ADDRESS_TYPE>
<STREET_LINE_1>P O BOX 1210</STREET_LINE_1>
<STREET_LINE_2/>
<CITY>MARION</CITY>
<STATE>AL</STATE>
<ZIP_CODE>36756</ZIP_CODE>
<COUNTY/>
<COLONIA/>
<COUNTRY>US</COUNTRY>
</IRP_ADDRESS>
</IRP_NAME>
</IRP_ACCOUNT>
</T0020>
In order to Insert this XML data to database ,we have used two XSLT.
First XSLT will remove name space from XML file and convert this XML to some intermediate
XML(say Process.xml) file on some temporary location.
then we were taking that intermediate xml(without namespace lines) and applied another XSL
to map xml field to Database.
Then we have found solution and we have used only one XSLT which does bode [1] Remove namespace and [2] Mapping XML field to Database to insert data.
Our final style sheet contain following lines
xmlns:t="http://www.safersys.org/namespaces/T0020V1">
and we used following to map field to Database
<xsl:template match="/">
<xsl:element name="T0020">
<xsl:apply-templates select="t:T0020/t:IRP_ACCOUNT" />
</xsl:element>
</xsl:template>
how did our problem solved with this approach ?Any consequences with using this ?
I have searched about this but not getting the functionality.
Thanks in Advance..
I don't see any problems with your approach.
XSLT mandates a fully qualified name for a correct matching, so using a prefixed namespace in your XSLT is the right solution; this is why you solved your problem.