Sample XML is given below.
<mapNode>
<mapNode>...</mapNode>
<mapNode>...</mapNode>-----I am here at 2
<mapNode>...</mapNode>
<mapNode>...</mapNode>
</mapNode>
<mapNode>
<mapNode>...</mapNode>
<mapNode>...</mapNode>
</mapNode>
I want to know whether position 3 exist or not.
Please help me.
Thanks in advance.
If you want to test if an element has a sibling following it, you can use the sensibly named "following-sibling" xpath expression:
<xsl:if test="following-sibling::*" />
Note that this will test if there is any following-sibling. If you only wanted to test for mapNode elements, you could do this
<xsl:if test="following-sibling::mapNode" />
However, this would also be true also in the following case, because following-sibling will look at all following siblings:
<mapNode>
<mapNode>...</mapNode>
<mapNode>...</mapNode>-----I am here at 2
<differentNode>...</differentNode>
<mapNode>...</mapNode>
</mapNode>
If you therefore want to check the most immediately following sibling was a mapNode element, you would do this:
<xsl:if test="following-sibling::*[1][self::mapNode]" />
In addition to #rene's answer you could also use the following-sibling axis from within any mapNode:
<xsl:template match="mapNode">
<xsl:if test="count(following-sibling::mapNode)>0">
<!-- has a successor -->
</xsl:if>
</xsl:template>
Not knowing what you already have but assuming you have a template to select a toplevel mapNode you can use count to findout how many mapNodes there are under thecurrent node:
<xsl:template match="/root/mapNode">
<xsl:if test="count(mapNode)>2">
more than two mapNodes
</xsl:if>
</xsl:template>
Related
Assume my xml input is a MFMATR element with a few child elements, such as: TRLIST, INTRO, and SBLIST -- in that document order. I am converting to HTML.
I have a template that matches on the MFMATR element, and wants to run xsl:apply-templates on the 3 child elements, but I want INTRO to be processed first (listed first in the HTML). The other two (TRLIST and SBLIST) should keep their relative document order, as long as INTRO comes before both of them.
So I'd like to run <xsl:apply-templates select="INTRO, *"> but not have INTRO matched twice. (Using this syntax with xsl 3.0 causes dupes for me.) I also don't want to explicitly list every tag in the select expression, so unknown tags will still be processed.
A 2nd real life example is this: <xsl:apply-templates select="TITLE, CHGDESC, *"/>. Again, right now that is causing dupes I don't want.
I am using Saxon.
So I'd like to run <xsl:apply-templates select="INTRO, *"> but not have INTRO matched twice
Try:
<xsl:apply-templates select="INTRO, * except INTRO">
This seems to work. If someone has a better answer, let me know and I will change it.
There is no DRY violation here -- no repeated element names or variable names. I want it to look clean at all the call sites I will have.
It seems idiomatic to me since the function was pulled from w3's own website!
<xsl:template match="MFMATR">
<!-- Process INTRO first, no matter where it appears -->
<xsl:variable name="nodes" select="INTRO, *"/>
<xsl:apply-templates select="kp:distinct_nodes_stable($nodes)"/>
</xsl:template>
<xsl:template match="INTRO">
<xsl:variable name="nodes" select="TITLE, CHGDESC, *"/>
<xsl:apply-templates select="kp:distinct_nodes_stable($nodes)"/>
</xsl:template>
<!-- Discard duplicate elements in $seq, but keep their ordering -->
<!-- Adapted from https://www.w3.org/TR/xpath-functions/#func-distinct-nodes-stable -->
<xsl:function name="kp:distinct_nodes_stable" as="node()*">
<xsl:param name="seq" as="node()*"/>
<xsl:sequence select="fold-left($seq, (),
function($foundSoFar as node()*, $this as node()) as node()* {
if ($foundSoFar intersect $this)
then $foundSoFar
else ($foundSoFar, $this)
}) "/>
</xsl:function>
I have problem with my code in XSLT with if. I am using key function and there I find out if something is in the key or not.
<xsl:key name="hlp" match="help" use="#id" />
...
<xsl:if test="key('hlp', #some_id) !=''">
...
</xsl:if>
That is correct it gives me what I want but how I can make opposite condition that #some_id isn´t in key hlp... I mean:
<xsl:if test="key('hlp', #some_id) <!--is equal--> ''">
...
</xsl:if>
Is there something like that in XSLT/XPath?
When you call key('x', 'y'), the result is the set of nodes in which the key is equal to 'y'. You can test whether a node-set is empty using the empty() function (in XSLT 2.0) or the not() function in XSLT 1.0:
<xsl:if test="not(key('x', 'y'))" version="1.0">...</xsl:if>
<xsl:if test="empty(key('x', 'y'))" version="2.0">...</xsl:if>
or for the inverse test (to test if something was found):
<xsl:if test="key('x', 'y')" version="1.0">...</xsl:if>
<xsl:if test="exists(key('x', 'y'))" version="2.0">...</xsl:if>
Testing by comparing the result against a string is wrong. The tests key('x','y')='' and key('x','y')!='' will both return false if the result of the key() function is an empty node-set; conversely, if the key() function selects two nodes, one with content and the other without, then both tests will return true.
<xsl:key name="hlp" match="help" use="#id" />
...
<xsl:if test="key('hlp', #some_id) !=''">
...
</xsl:if>
As already pointed by Michael Kay, avoid using the != operator unless truly knowing what it does.
This aside (and the fact that the key() function returns a node-set), it is more in the spirit of XSLT to write the above as:
<xsl:apply-templates select="key('hlp', #some_id)"/>
but how I can make opposite condition that #some_id isn´t in key
hlp... I mean:
<xsl:if test="key('hlp', #some_id) <!--is equal--> ''">
...
</xsl:if> ```
Is there something like that in XSLT/XPath?
Again, in the spirit of XSLT I recommend using code like this:
<xsl:apply-templates select="/*[not(key('hlp', #some_id))]" mode="not-found"/>
In the select expression above one can substitute /* with any existing node in the document -- if this really matters.
In XSLT 2.0 and XPATH, within <xsl:template match="lb">, I am testing for a variety of different case where each case produces different HTML output (using xsl:choose/xsl:when).
I want to test for the following situation, where lb is the very first node of any sort inside seg element:
<seg><lb break="n"/>text</seg>
By contrast, these tests would fail:
<seg>text<lb break="n"/>text</seg>
<seg><foo/><lb break="n"/>text</seg>
I've tried combining parentand position() but it's not testing correctly.
Many thanks.
Having a template matching lb and then using xsl:choose/when in my view can be solved more elegantly and compact with precise match patterns e.g. xsl:template match="seg/node()[1][self::lb]" would match any first child node of a seg parent where the child is an lb element. For other conditions you would set up different templates with different match patterns.
But you can use . is parent::seg/node()[1] inside the xsl:template match="lb" to write it the other way around if needed.
/seg/child::node()[1]/name() = 'lb'
check if first child is named "lb"
You can simply test if there are no preceding siblings:
<xsl:when test="not(preceding-sibling::node())">
Do note that node() includes comments and processing instructions too, not just elements and text.
Alternatively, if you have a template matching seg where you do something like this...
<xsl:template match="seg">
<xsl:copy>
<xsl:apply-templates />
</xsl:copy>
</xsl:template>
Then, because <xsl:apply-templates /> is short for <xsl:apply-templates select="node()" /> you could use position() in your template
<xsl:when test="position() = 1">
This would not work if the "seg" template did <xsl:apply-templates select="lb" /> though.
See http://xsltfiddle.liberty-development.net/nc4NzRd for an example of the tests in action.
More for reference than actual need: what is the XPath syntax to allow me to reference an element in a xsl:for-each block when the same element name is used elsewhere?
Please note, unfortunately this must be a 1.0 solution
For example, I have the following simple XML, and I want to match up the items with the same id value...
<data>
<block1>
<item><id>1</id><text>Hello</text></item>
<item><id>2</id><text>World</text></item>
</block1>
<block2>
<item><id>1</id><text>123</text></item>
<item><id>2</id><text>ABC</text></item>
</block2>
</data>
If I have a for-each on the block1, how can I reference both the id within the block1 and the id within the block2?
This will work, but I think it is messy...
<xsl:for-each select="//block1/item">
<xsl:variable name="id" select="id"/>
<xsl:value-of select="text"/> - <xsl:value-of select="//block2/item[id=$id]/text"/>
</xsl:for-each>
With the result of...
Hello - 123
World - ABC
Is there a simplified way of replacing the $id in select="//block2/item[id=$id]/text" so that it is referring to the id element from the for-each?
Another way to do it which you may find clearer, and will probably be faster, is to use keys:
<xsl:key name="b2" match="block2/item" use="id"/>
then
<xsl:value-of select="key('b2', id)/text"/>
What you have is correct and common as it is. There's no need to simplify it further; it's a standard idiom recognized and used by those working with XSLT.
I have an XML with 2 XML fragments, 1st one is a fragment where the new values must be applied (which can have pretty complex elements) like
... some static parents
<a:element1>
<a:subelement tag="someString">
<a:s1>a</a:s1>
</a:subelement>
</a:element1>
<a:element2>b</a:element2>
<a:element3>c</a:element3>
... lots of other elements like the above ones
and 2nd fragment that has XPaths generated from the first XML and a new value, like
<field>
<xpath>/Parent/element1/subelement[#tag="someString"]/s1</xpath>
<newValue>1</newValue>
</field>
<field>
<xpath>/Parent/element2</xpath>
<newValue>2</newValue>
</field>
We might not have new values to apply for all the elements in the first fragment.
I'm struggling to make an XSLT transformation that should apply the new values to the places indicated by the XPaths.
The output should be:
... some static parents
<a:element1>
<a:subelement tag="someString">
<a:s1>1</a:s1>
</a:subelement>
</a:element1>
<a:element2>2</a:element2>
... lots of other elements like the above ones
I have access to xalan:evaluate to evaluate the dynamic xpath. I'm trying different solutions, I will write them here when they will start to make sense.
Any ideas of approaches are well received. Thanks
Oki, I found out how, and I will write the answer here maybe someone sometime will need this:
<xsl:template match="/">
<!-- static parents -->
<a:Root>
<xsl:apply-templates select="/a:Root/a:Parent" />
</a:Root>
</xsl:template>
<xsl:template match="#*|*|text()">
<xsl:variable name="x" select="generate-id(../.)" />
<xsl:variable name="y" select="//field[generate-id(xalan:evaluate(xpath)) = $x]" />
<xsl:choose>
<xsl:when test="$y">
<xsl:value-of select="$y/newValue" />
</xsl:when>
<xsl:otherwise>
<xsl:copy>
<xsl:apply-templates select="#*|*|text()" />
</xsl:copy>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
And to explain the transformation:
I'm writing down part that is static and then call apply-templates on the fragment I'm interested in, that has a liquid structure.
Then I'm using a slightly modified identity transformation that copies everything from source to target (starting from the /a:Root/a:Parent fragment), except when we position ourselves on the text I'm interested in changing.
The text() I'm interested in will have as parent (../.) the element referred by an xpath string found in the second fragment. Variable x means, in the context of the when, this element.
Variable y finds a field element that has as child an xpath element that if evaluated using xalan will refer to the same element that the x variable relates to.
Now I used generate-id() in order to compare the physical elements, otherwise it would have compared by the toString of the element (which is wrong). If variable y doesn't exist, it means that I have no xpath element for this element that could have changed, and I'm leaving it alone. If the y variable exists, I can get from it the newValue and I'm currently positioned on the element which text I want to update.