Manage flags in xslt? - xslt

All,
i am searching in a list of fields those who has the type clob and i am writing it separed by a comma like this [field1, field2, ... fieldn]
my problem is how to identify the first matched field to write it without comma ( i can't use position() because the first field matched can be the first of the list or the last of the list)
I want to make this algorithm in xslt,
variable is_first = TRUE;
if(is_first) {
do smthng;
isfirst = False;
}

Actually it is not possible to make something like this in xslt since variable are immutable. There probably could be workarounds but you have to specify your need in more details.
edit:
If your input is string with values separated by commas...
<xsl:variable name="inputString" select="'field1,field2,field3a,field4,field3b'" />
... you could use tokenize() functions...
<xsl:variable name="tokenized" select="tokenize($inputString, ',')" />
... and then select items corresponding to your condition
<!-- Select item corresponding to condition (e.g. it contains 3). Take first one if there are several such items -->
<xsl:value-of select="$tokenized[contains(., '3')][1]" />
Edit2:
You can use separator attribute of xsl:value-of (xslt 2.0) for output of delimited values.
Assuming following variable
<xsl:variable name="list">
<item>first</item>
<item>second</item>
<item>third</item>
</xsl:variable>
this <xsl:value-of select="$list/item" separator="," /> makes desired output first,second,third

You need to write this using functional code rather than procedural code. It's not possible to do the conversion without seeing the context (it's much easier to work from the problem rather than from the solution in a lower-level language).
But the most common equivalent in XSLT would take the form
<xsl:for-each select=".....">
<xsl:if test="position() = 1"><!-- first time code --></xsl:if>
....
</xsl:for-each>

Related

How can you apply concat(...) in a value-of directive in case of multiple nodes?

I am outputting the name node of each property node in a ; delimited string as following:
<xsl:value-of select="properties/property/name" separator=";" />
I want to alter this such that each element is prefixed with _. An example output should be:
_alpha;_beta;_gamma
I tried the following:
<xsl:value-of select="concat('_', properties/property/name)" separator=";" />
I want to use this to create an output node containing that string:
<my_node>
<xsl:value-of select="concat('_', properties/property/name)" separator=";" />
</my_node>
This gives an error when there are multiple properties:
XPTY0004: A sequence of more than one item is not allowed
as the second argument of fn:concat() (<name>, <name>)
Is there a way to get this working in XSLT 2.0/3.0?
I could resort to the XSLT 1.0 for-each solution as given in https://stackoverflow.com/a/57856287/12042211 (in which we are manually adding the separator), but I am wondering if something elegant in XSLT 2.0/3.0 is possible.
The answer is yes. XSLT 2.0 allows you to write expressions like this...
<xsl:value-of select="properties/property/concat('_', name)" separator=";" />
So, for each property it selects the concatenation of "_" with the name element.
Such syntax is not valid in XSLT 1.0 though.
In XSLT 3.0 I would tend to write this as
<xsl:value-of select="properties/property ! ('_' || name)" separator=";" />
and perhaps use string-join() instead of xsl:value-of. You haven't shown the context, but try to use xsl:value-of only when you really want a text node, not when you just want a string.

convert <xsl:variable> string value , to the value which I can select with <xsl:value-of select>

I have a variable from which I need to dynamically generate nodes
<xsl:template match="banner_discount_1 | banner_discount_2 | banner_discount_3">
<xsl:variable name="link">banner_discount_<xsl:value-of select="substring-after(name(.) ,'banner_discount_')" />_link</xsl:variable>
<xsl:value-of select="$link" />
</xsl:template>
<xsl:value-of> selects the string, but I want to be able to select the node which name matches the name of a variable.
In my case the node looks something like this:
<banner_discount_1_link />
<banner_discount_2_link />
...
Here is the xml I'm using
<banner_discount_1> 12 </banner_discount_1>
<banner_discount_2> 21 </banner_discount_2>
<banner_discount_3> 32 </banner_discount_3>
<banner_discount_1_link> link1 </banner_discount_1_link>
<banner_discount_2_link> link2 </banner_discount_2_link>
<banner_discount_3_link> link3 </banner_discount_3_link>
#MartinHonnen is on the right track, but you need to set the selection context as well.
Since you're in a template that's selecting the banner_discount_ nodes, that is your context. From your XML sample, it looks like the nodes you want to select are siblings, so this should work:
<xsl:value-of select="../*[local-name() = $link]"/>
It is preferable to target the nodes directly, but if they could be anywhere in the document, then you may resort to
<xsl:value-of select="//*[local-name() = $link]"/>
This is a last resort because it is potentially O(n) with respect to the number of nodes in the document.
Use <xsl:value-of select="*[local-name() = $link]"/>. If that does not help then consider to show a sample of the XML.

Creating a variable number of nodes on target document without corresponding data on source document

I'm trying to map two documents witht the BizTalk Mapper and my target document should look like this:
<root>
<complexType>
<property>example</property>
</complexType>
<filler>
<padding>9999999</padding>
</filler>
<filler>
<padding>9999999</padding>
</filler>
<filler>
<padding>9999999</padding>
</filler>
</root>
The number of <filler> nodes that I should create is variable (from 0 to 9). It is basically the result of a calculation (based on some data provided in the source document).
Is there a way to create those <filler> nodes with some combination of functoids?
I tried to use the Table Looping functoid (created a table with only one column, the padding char '9') but doesn't really work because it creates as many <filler> nodes as rows are defined in the table, which is not what I want since the number of rows would have to be variable (again, based on a calculation).
What I currently do is pass the message (XmlDocument) to a C# method and then I programmatically append the <filler> nodes.
I'm hoping that there is a more "BizTalk-y" way of doing this with the Mapper.
I suspect that you will have to solve this problem by altering the XSLT.
Add some logic to create as many filler nodes as the result of your calculation dictates - you could create a template which you call in a loop perhaps, which would append a new filler section.
Hope this points you in the right direction.
As pointed out, XSLT can create nodes on the target document at will (I didn't know this and this was the key part).
Turns out that what I needed is a simple for-loop in XSLT. Once I realized this, a quick Google search yielded the following results:
http://quomon.com/question-How-to-make-a-for-loop-in-xslt-not-for-each-809.aspx
http://snippets.dzone.com/posts/show/930
Another thing worth noting is that (as pointed out by the first link), XSLT is a functional language, not procedural, so sometimes you do have to resort to using recursion or an extension.
This case is definitely one of those times since I couldn't use a careful selection of nodes using the select attribute on an xsl:for-each (since this filler data wasn't part of the source document).
Specifically, for this case, what I did was:
Add a Scripting functoid.
Add two inputs:
A constant with value "1" (this is the initial value of the i variable)
The length of the loop (number of times to repeat the body of the loop)
Paste the following XSLT template as an "Inline XSLT Call Template" script:
<xsl:template name="ForLoop">
<xsl:param name="i" /> <!-- index counter, 1-based, will be incremented with every recursive call -->
<xsl:param name="length" /> <!-- exit loop when i >= length -->
<!-- Output the desired node(s) if we're still looping -->
<!-- The base case is when i > length (in that case, do nothing) -->
<xsl:if test="$i <= $length">
<Filler>
<Padding>999999</Padding>
</Filler>
</xsl:if>
<!-- Call the ForLoop template recursively, incrementing i -->
<xsl:if test="$i <= $length">
<xsl:call-template name="ForLoop">
<xsl:with-param name="i">
<xsl:value-of select="$i + 1"/>
</xsl:with-param>
<xsl:with-param name="length">
<xsl:value-of select="$length"/>
</xsl:with-param>
</xsl:call-template>
</xsl:if>
</xsl:template>

Biztalk explode in XSLT transformations

I'm receiving XML into BizTalk. One part is element and the value is ids separated by comma
<Stores>15,34</Stores>
I need to transform this into
<Stores>
<Store>Store 1</Store>
<Store>Store 4</Store>
</Stores>
What I need to do is to explode the value by comma, take each value and get value from database (15 -> Store 1, 34 -> Store 2).
How can I make the explode in xslt, how ca I get value from database for each exploded value. I already have procedure in db for that, just need to know how to call it.
Here is an XSLT 1.0 compatible solution that does the explode:
<!-- straightforward -->
<xsl:template match="Stores">
<xsl:copy>
<xsl:call-template name="explode">
<xsl:with-param name="str" select="text()" />
</xsl:call-template>
</xsl:copy>
</xsl:template>
<!-- string processing through recursion -->
<xsl:template name="explode">
<xsl:param name="str" select="''" />
<xsl:variable name="temp" select="concat($str, ',')" />
<xsl:variable name="head" select="substring-before($temp, ',')" />
<xsl:variable name="tail" select="substring-after($temp, ',')" />
<xsl:if test="$head != ''">
<Store>
<xsl:value-of select="$head" />
</Store>
<xsl:call-template name="explode">
<xsl:with-param name="str" select="$tail" />
</xsl:call-template>
</xsl:if>
</xsl:template>
Output for <Stores>15,34</Stores> would be:
<Stores>
<Store>Store 15</Store>
<Store>Store 34</Store>
</Stores>
David Hall's solution seems to contain a pointer how to use an XSLT extension function to make calls to that database from XSLT.
The BizTalk Mapper does not support XSLT 2.0 (see MSDN Documentation http://msdn.microsoft.com/en-us/library/aa559261(BTS.10).aspx) so you will need to use the EXSLT extensions if you want to use the mapper.
There is a great post here by Richard Hallgren that covers how to use EXSLT within the BizTalk Mapper.
One additional thought is about an alternative solution. It is not clear if you absolutely must make your database calls one by one - would making a single call work?
It is possible to provide a stored procedure a delimited string as a parameter and to then use a function to break this string up. I've included an example of such a function below, the example being a table function. You'll be able find lots of other implementations on the web.
With the table function you can join against this in you store lookup procedure.
If this meets your needs it should be a lot faster since you now perform just a single database hit and can perform set operations to get back your list of stores.
CREATE function fn_ParseCSVString
(
#INPUTCSV varchar(MAX)
)
RETURNS #TBL TABLE
(
COL1 INT
)
AS
BEGIN
DECLARE #NUM_STR NVARCHAR(MAX)
SET #NUM_STR = #INPUTCSV
SET #NUM_STR = REPLACE(#NUM_STR,' ','')
-- this will trim any intermediate spaces
WHILE LEN(#NUM_STR) >= 0
BEGIN
DECLARE ##SUBSTR VARCHAR(100)
IF CHARINDEX(',',#NUM_STR,0) <> 0
BEGIN
SET ##SUBSTR = SUBSTRING(#NUM_STR,0,CHARINDEX(',',#NUM_STR,0))
INSERT INTO #TBL VALUES(##SUBSTR)
END
ELSE
BEGIN
INSERT INTO #TBL VALUES(#NUM_STR)
BREAK
END
SET ##SUBSTR = ##SUBSTR + ','
SET #NUM_STR = SUBSTRING(#NUM_STR, CHARINDEX(',',#NUM_STR,0) + 1, LEN(#NUM_STR))
END
RETURN
END
I assume you know how to write the overall transform but need help with the tokenization of the string containing the store numbers.
If you're using XSLT 2.0, look at the definition of the tokenize() function. This will split the string value at a specified delimiter, allowing you to perform this transformation. In XSLT 1 you could look at EXSLT regex extension functions.

How-to break a for-each loop in XSLT?

How-to break a for-each loop in XSLT?
XSLT is written in a very functional style, and in this style there is no equivalent of a break statement. What you can do is something like this:
<xsl:for-each select="...nodes...">
<xsl:if test="...some condition...">
...body of loop...
</xsl:if>
</xsl:for-each>
That way the for-each will still iterate through all the nodes, but the body of the loop will only be executed if the condition is true.
Put the condition for stopping the "loop" in the select attribute of the for-each element. For instance, to "break" after four elements:
<xsl:for-each select="nodes[position()<=4]">
To iterate up to but not including a node that satisfied some particular condition:
<xsl:for-each select="preceding-sibling::node[condition]">
XSLT isn't a procedural language; don't think of for-each as being a "loop" in the way you have a loop in Java. For-each is a way to apply a template to each of a bunch of items. It doesn't necessarily happen in a particular order, so you can't think of it as "apply this template to each of a bunch of items until such-and-such happens, then stop".
That said, you can use the select attribute to filter the results, so it becomes more like "apply a template to each of a bunch of items, but only if such-and-such is true of them".
If what you really want is "apply a template to each of a bunch of items, where such-and-such is true of them, but only to the first one this is true of", you can combine the select attribute with the position() function.
A "break" from the body of an <xsl:for-each> XSLT instruction cannot be specified using a syntactic construct, however it can be simulated.
Essentially two techniques are discussed:
Performing something inside the body of <xsl:for-each> only if a specific condition is satisfied. This can be improved if the condition can be specified in the select attribute of <xsl:for-each> -- in this case only the necessary nodes will be processed. See for example: https://stackoverflow.com/a/7532602/36305
Specifying the processing not using <xsl:for-each> but with recursion. There are many examples of recursive processing with XSLT. See the code at: https://fxsl.sf.net/
The second method has the benefit of being able to perform the exit immediately, contrasted with the first method having to still perform many "empty cycles" even after the exit-condition has been satisfied.
I had a similar situation and here is the code I had written. For logical reasons, I couldn't fit in the other conditions with condition01.
<xsl:for-each select="msxsl:node-set($DATA6)[condition01]">
<xsl:choose>
<xsl:when test="not((condtion02 or condition03) and condition04)">
--body of for loop
</xsl:when>
</xsl:choose>
</xsl:for-each>
Hello I kwow this is an old post but maybe it can help other developers. I have found a way to break a for each in XSLT it is not litteraly a break but if you see the code you will get it. As you know or not know you can use inline C# code in xslt. In this example i want to loop al the nodes and take the first NTE node with Value RC But if I get a node that differs from the NTE node i want to stop looking at the condition. So I set a global variable in C# code and I ask the value each time I go through a node:
<xsl:value-of select="userCSharp:SetStopForeach('true')" />
<xsl:for-each select="following-sibling::node()">
<xsl:if test="local-name()='NTE_NotesAndComments_3' and userCSharp:GetStopForeach()" >
<xsl:for-each select="NTE_4_CommentType">
<xsl:if test="(CE_0364_0_IdentifierSt)[text()="RC"]">
<ns0:RESULTAAT_COMMENTAAR>
<xsl:for-each select="../NTE_3_Comment">
<xsl:value-of select="./text()" />
</xsl:for-each>
</ns0:RESULTAAT_COMMENTAAR>
</xsl:if>
</xsl:for-each>
</xsl:if>
<xsl:if test="local-name()='ORC_CommonOrder'" >
<xsl:value-of select="userCSharp:SetStopForeach('false')" />
</xsl:if>
</xsl:for-each>
.....
<msxsl:script language="C#" implements-prefix="userCSharp">
<![CDATA[
public bool StopForeach=false;
public bool GetStopForeach() {
return StopForeach;
}
public string SetStopForeach(bool aValue) {
StopForeach=aValue;
return "";
}
]]>
</msxsl:script>