xslt

[leblancmeneses]

how is white space managed in xslt?

I'm going write a code generation tool that
writes my model from my database.


I would like to create from this code:



<column name="Name" type="int" />
the following:



public Int32 Name
{
get;
set;
}

i plan to use xslt to "choose" to decide how to convert database types to language types.

my question is can a template provide a pretty output as in that property without



public
Int32
Name
{
get;
set;
}


how is white space managed? in xslt template?

lm

[Reiger]

You could use the following property:


<xsl:output method="text" />



Combined with a top level variable
<xsl:variable name="myindent" select="''" /> and indent stuff like so:
<xsl:value-of select="$myindent" /> Just make sure that you give $myindent a proper value.

If it had been XML you were outputtting things would've been easier:


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

[leblancmeneses]

seems i can also do it using a named template.

except i don't know how to dynamically assign:
_propertyDatatype




<xsl:template name="CreateProperty">
<xsl:param name="propertyDatatype" required="yes" />
<xsl:param name="propertyName" required="yes" />
public <xsl:value-of select="$propertyDatatype"/> <xsl:value-of select="$propertyName"/>
{
get;
set;
}
</xsl:template>



<xsl:template match="Columns/Column">
<xsl:variable name="_propertyDatatype" select="'Int32'" />
<xsl:choose>
<xsl:when test="ColumnType[text()='OrmInt']">
_propertyDatatype = 'Int32'
</xsl:when>
<xsl:when test="ColumnType[text()='OrmTextShort']">
_propertyDatatype = 'String'
</xsl:when>
<xsl:otherwise>
_propertyDatatype = 'Unknown'
</xsl:otherwise>
</xsl:choose>
<xsl:call-template name="CreateProperty">
<xsl:with-param name="propertyDatatype" select="$_propertyDatatype"/>
<xsl:with-param name="propertyName" select="@Name"/>
</xsl:call-template>
</xsl:template>


anyone?


what are the popular xslt designers ... kinda like wysiwyg

[Reiger]

You are dealing with a mostly functional programming language. You do not have destructive update: you define the value of your variable once, and only once. Fortunately for you: the value of your variable may be a function of its input:


<xsl:variable name="foo">
<xsl:choose>
<xsl:test when="local-name() = 'foo'"><xsl:value-of select="'case foo'"/></xsl:test>
<xsl:test when="local-name() = 'bar'"><xsl:value-of select="'case bar'"/></xsl:test>
<xsl:otherwise><xsl:value-of select="'default'"/></xsl:otherwise>
</xsl:coose>
</xsl:variable>


And it can be much more complex than that: you could have the result of a template call on the current node be stored in $foo this way, to be used later on.

EDIT: Also I am not aware of `designers' like that. While it is in theory possible to write programs that generate your XSLT on the fly (on rules defined via drag-drop or whatever have you); I doubt it is very widespread. You don't see many generic 'visual designers' for writing generic C solutions to a given problem either.

[leblancmeneses]

this stuff is pretty impressive!


quick code review:

currently accessing ancestor is very coupled to xml layout

instead of: ../../../../../ is there a way i can say
(select-parent-of-type="Project")/@NameSpace

rather than current implementation?


<xsl:template match="/Projects/Project/Database/Schemas/Schema/Tables/Table">
namespace <xsl:value-of select="../../../../../@NameSpace"/>
{
public class <xsl:value-of select="@Name"/>
{
<xsl:for-each select="Columns/Column">
<xsl:apply-templates select="." />
</xsl:for-each>
}
}
</xsl:template>





clearing up spacing in xslt.
right now i'm having to use 'concat' to achieve proper spacing between:
Int32 and column name.

maybe this is specific to msxsl.exe i'm using or is spacing ignored in the line once xsl tag is encountered?



to get a property to have space:
public Int32 customer_id
{
get;
set;
}


I had to use concat a ' ' space else it would look like this:
public Int32customer_id
{
get;
set;
}





<xsl:template name="CreateProperty">
<xsl:param name="propertyDatatype" required="yes" />
<xsl:param name="propertyName" required="yes" />
public <xsl:value-of select="concat($propertyDatatype, ' ')"/> <xsl:value-of select="$propertyName"/>
{
get;
set;
}
</xsl:template>

[Reiger]

Well there are ways, all of them boil down to a more comprehensive understanding of XPath. http://www.w3schools.com/xpath/xpath_axes.asp

For instance you need not look at a DOM tree in terms of `how many ancestors came before me?', but you could also look at it in terms of `do I have an ancestor called Fred?': e.g.:
test.xml:


<?xml-stylesheet type="text/xsl" href="test.xsl"?>
<tree><fred><frank><me /></frank></fred>
<frank><me /></frank></tree>


test.xsl:


<xsl:transform version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<test>
<xsl:apply-templates />
</test>
</xsl:template>

<xsl:template match="//me">
<result>
<xsl:choose>
<xsl:when test="ancestor::fred">
<xsl:text>Bingo!</xsl:text>
</xsl:when>
<xsl:otherwise>
<xsl:text>Nope!</xsl:text>
</xsl:otherwise>
</xsl:choose>
</result>
</xsl:template>
</xsl:transform>

Use a browser like Opera to see the result (by browsing to file://localhost/[some directory here]/test.xml)

[leblancmeneses]

xslt is getting pretty large.

I need to do something as follows

any template in scope of . -> /Projects/Project
is evaluated with passed variable propertyProjectGUID // auto generated by function - should be consistent across all templates

and output is piped to result-document?

code as follows would be the goal


<xsl:variable name="projectname" select="concat($projectDirectory, '/', $projectNameSpace, '.csproj')" />
<xsl:result-document href='{$projectname}' format="textFormat">
<xsl:apply-templates select=".">
<xsl:with-param name="propertyProjectGUID" select="$projectguid"/>
</xsl:apply-templates>
</xsl:result-document>

[Reiger]

If you want to basically `dynamically include' other XML documents there are XIncludes. Note that this will require you to adopt the more formal and verbose element declarations.

I have never done this extensively myself so I am probably wrong in the details; take care to ensure that the code is correct yourself:


<xsl:element name="include" namespace="this-is-wrong-look-up-the-correct-Xinclude-ns">
<xsl:attribute name="parse"><!-- include as plain text, change to XML or remove to include as XML -->
<xsl:value-of select="'text'/>
</xsl:attribute>
<xsl:attribute name="href"><xsl:value-of select="$doc-to-include"/></xsl:attribute>
</xsl:element>


That should generate something like:

<xi:include xmlns:xi="this-is-wrong-look-up-the-correct-Xincludes-ns" parse="text" href="somefile" />

Then you may either need to pass it through something to resolve the include, or you may already get that for free. That will depend on the tools/libraries you use.