xpath 1.0 set the value of non existent attribute - xpath

I have a xml document
<?xml version="1.0" encoding="UTF-16"?>
<APIDATA xmlns="api-com">
<ORDER EngineID="1" OrderID="66" OtherInfo="100"><INSTSPECIFIER InstID="27" SeqID="17"/>
</ORDER>
<ORDER EngineID="2" OrderID="67" OtherInfo="200"><INSTSPECIFIER InstID="28" SeqID="18"/>
</ORDER>
<ORDER EngineID="3" OrderID="68"><INSTSPECIFIER InstID="29" SeqID="19"/></ORDER>
</APIDATA>
How do i get the value of OtherInfo attribute using xpath
but when it does not exist i want Null to be returned
If i used the following xpath /APIDATA/ORDER/#OtherInfo i get the output as
100
200
But since for OrderID 68 the OtherInfo is missing i want the output to be
100
200
0
There is a post here which is close to my solution but i somehow cant get it to work
Can I create a value for a missing tag in XPath?

Unfortunately, the approach in the answer to the linked question only work if there is only one value to be returned from a given XML document (see below for a demo on this point). So given the XML sample posted in this question, short answer would be this can't be done using pure XPath 1.0.
If the XPath is used within a programming language, one possible approach would be, to use XPath expression that always return a value, for example /APIDATA/ORDER. Then, for each <ORDER> element returned, usually there are plenty of options to get OtherInfo attribute and provide default value in case the attribute is not found.
Applying the linked post approach to your case would results in the following XPath expression :
substring(concat("0", //ORDER[3]/#OtherInfo), 2 * number(boolean(//ORDER[3]/#OtherInfo)))
The XPath successfully return 0 when applied to the 3rd <ORDER> element which doesn't have attribute OtherInfo, see the demo* : xpathtester, xpatheval
default namespace has been removed in the demo for the sake of simplifying the XPath
Implementation of the same approach in XSLT 1.0, as requested :
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:d="api-com">
<xsl:output method="text" indent="yes"/>
<xsl:template match="d:ORDER">
<xsl:value-of select="substring(concat('0', #OtherInfo), 2 * number(boolean(#OtherInfo)))"/>
</xsl:template>
</xsl:stylesheet>
output :
100
200
0
Demo : xpathtester

Related

Split methods on XPath 1.0

I use 'XPath', how I can simulate split method?
I read documentation and I know that XPath version 1.0 not have this method.
I have document contains this tags:
<TestCategoryModule>
<ItemCategories>
<![CDATA[Birthday Travel,Travel]]>
</ItemCategories>
</TestCategoryModule>
<TestCategoryModule2>
<ItemCategories>
<![CDATA[Travel]]>
</ItemCategories>
</TestCategoryModule2>
I want filter item by 'ItemCategories', but when I filtered by world 'Travel', return 2 item. I use this filter "ItemCategories[contains(text(), 'Travel')]".
I want that I filter by "Travel" return only second item. How can do it?
Use:
/*/*/*[contains(concat(',', ., ','), ',Travel,')]
Here is XSLT-based verification:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
<xsl:copy-of select=
"/*/*/*[contains(concat(',', ., ','), ',Travel,')]"/>
</xsl:template>
</xsl:stylesheet>
When this transformation is applied on this XML document (essentially the provided XML fragment, extended with one more test case and made a well-formed XML document:
<t>
<TestCategoryModule>
<ItemCategories>Birthday Travel,Travel</ItemCategories>
</TestCategoryModule>
<TestCategoryModule2>
<ItemCategories>Birthday Travel</ItemCategories>
</TestCategoryModule2>
<TestCategoryModule2>
<ItemCategories>Travel</ItemCategories>
</TestCategoryModule2>
</t>
The wanted, correct result is produced:
<ItemCategories>Birthday Travel,Travel</ItemCategories>
<ItemCategories>Travel</ItemCategories>
I was a little wrong, or poorly described problumu. The problem is that the categories are stored as a string. I have three items, the first one contains categories: (Birthday Travel,Travel), second: (Birthday Travel), third: (Travel). When I request filtering for the word "Travel", I need to get the first and third items, but I get all three items, because all items contain world "Travel".
You actually don't need split() for the problem that you've described. If you want to match Travel but not Travel,Travel you want = instead of contains(). To deal with the whitespace around your CDATA sections, wrap it in normalize-space().
All put together, try ItemCategories[normalize-space(text()) = 'Travel'].

XSLT Function Return Type

Originally: **How to apply XPath query to a XML variable typed as element()* **
I wish to apply XPath queries to a variable passed to a function in XSLT 2.0.
Saxon returns this error:
Type error at char 6 in xsl:value-of/#select on line 13 column 50 of stackoverflow_test.xslt:
XTTE0780: Required item type of result of call to f:test is element(); supplied value has item type text()
This skeleton of a program is simplified but, by the end of its development, it is meant to pass an element tree to multiple XSLT functions. Each function will extract certain statistics and create reports from the tree.
When I say apply XPath queries, I mean I wish to have the query consider the base element in the variable... if you please... as if I could write {count(doc("My XSLT tree/element variable")/a[1])}.
Using Saxon HE 9.7.0.5.
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:f="f:f">
<xsl:template match="/root">
<xsl:variable name="first" as="element()*">
<xsl:copy-of select="(./a[1])" />
</xsl:variable>
<html>
<xsl:copy-of select="f:test($first)" />
</html>
</xsl:template>
<xsl:function name="f:test" as="element()*">
<xsl:param name="frstElem" as="element()*" />
<xsl:value-of select="count($frstElem/a)" />
<!-- or any XPath expression -->
</xsl:function>
</xsl:stylesheet>
Some example data
<root>
<a>
<b>
<c>hi</c>
</b>
</a>
<a>
<b>
<c>hi</c>
</b>
</a>
</root>
Possibly related question: How to apply xpath in xsl:param on xml passed as input to xml
What you are doing is perfectly correct, except that you have passed an a element to the function, and the function is looking for an a child of this element, and with your sample data this will return an empty sequence.
If you want f:test() to return the number of a elements in the sequence that is the value of $frstElem, you can use something like
<xsl:value-of select="count($frstElem/self::a)" />
instead of using the (implicit) child:: axis.

How to write the Regular expression for the Below to use in Webdriver?

I have a requirement for webdriver to use xpath using Regular expression.I have a list of id's with different values.How can i write a expression for the below type of values.
//*[#id="js_1"]
//*[#id="js_2"]
//*[#id="js_3"]
//*[#id="js_4"]
//*[#id="js_5"]
//*[#id="js_6"]
I have to write the regrular expression for that above xpath format using webdriver?
I have tried with the below
Listnames=box.findElements(By.xpath("//div[contains(#id, 'js_*')]"));
But it wont work for me.How can i write a expression.Please help me.
Thanks & Regards,
Shiva Oleti
If you use js_* as standard regular expression it matches js, js_, js__, js___ ...
The correct regular expression would be js_\d+
However, the XPath contains function does not use regular expressions, so you can just use js_ (although it won't check for numbers).
Or better
`//div[starts-with(#id, 'js_')]`
AFAIK, Webdriver supports XQuery (such as using XQUIB), therefore full XPath 2.0 is supported.
Use:
//*[matches(#id, '^js_\d+$')]
XSLT-2.0 - based verification:
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="/">
<xsl:sequence select="//*[matches(#id, '^js_\d+$')]"/>
</xsl:template>
</xsl:stylesheet>
when this transformation is applied on the following XML document:
<t>
<x id="js_1"/>
<y id="a1"/>
<z id="js_2008"/>
</t>
the above XPath expression is evaluated and the result of this evaluation is copied to the output:
<x id="js_1"/>
<z id="js_2008"/>
Explanation:
Proper use of the XPath 2.0 function matches() and RegEx.
Else you can use a loop to add elements to your list ...
List <WebElement> ls = null;
i=1;
while(i<5)
{
ls.add(we.findElement(By.xpath("html/body/div[1]/div/div[2]/section/nav/div[2]/ul/li["+i+
"]")));
i++;
}

Sorting XPath results in the same order as multiple select parameters

I have an XML document as follows:
<objects>
<object uid="0" />
<object uid="1" />
<object uid="2" />
</objects>
I can select multiple elements using the following query:
doc.xpath("//object[#uid=2 or #uid=0 or #uid=1]")
But this returns the elements in the same order they're declared in the XML document (uid=0, uid=1, uid=2) and I want the results in the same order as I perform the XPath query (uid=2, uid=0, uid=1).
I'm unsure if this is possible with XPath alone, and have looked into XSLT sorting, but I haven't found an example that explains how I could achieve this.
I'm working in Ruby with the Nokogiri library.
There is no way in XPath 1.0 to specify the order of the selected nodes.
XPath 2.0 allows a sequence of nodes with any specific order:
//object[#uid=2], //object[#uid=1]
evaluates to a sequence in which all object items with #uid=2 precede all object items with #uid=1
If one doesn't have anXPath 2.0 engine available, it is still possible to use XSLT in order to output nodes in any desired order.
In this specific case the sequence of the following XSLT instructions:
<xsl:copy-of select="//object[#uid=2]"/>
<xsl:copy-of select="//object[#uid=1]"/>
produces the desired output:
<object uid="2" /><object uid="1" />
I am assuming you are using XPath 1.0. The W3C spec says:
The primary syntactic construct in XPath is the expression. An expression matches the production Expr. An expression is evaluated to yield an object, which has one of the following four basic types:
* node-set (an unordered collection of nodes without duplicates)
* boolean (true or false)
* number (a floating-point number)
* string (a sequence of UCS characters)
So I don't think you can re-order simply using XPath. (The rest of the spec defines document order and reverse document order, so if the latter does what you want you can get it using the appropriate axis (e.g. preceding).
In XSLT you can use <xsl:sort> using the name() of the attribute. The XSLT FAQ is very good and you should find an answer there.
An XSLT example:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:param name="pSequence" select="'2 1'"/>
<xsl:template match="objects">
<xsl:for-each select="object[contains(concat(' ',$pSequence,' '),
concat(' ',#uid,' '))]">
<xsl:sort select="substring-before(concat(' ',$pSequence,' '),
concat(' ',#uid,' '))"/>
<xsl:copy-of select="."/>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
Output:
<object uid="2" /><object uid="1" />
I don't think there is a way to do it in xpath but if you wish to switch to XSLT you can use the xsl:sort tag:
<xsl:for-each select="//object[#uid=1 or #uid=2]">
<xsl:sort: select="#uid" data-type="number" />
{insert new logic here}
</xsl:for-each>
more complete info here:
http://www.w3schools.com/xsl/el_sort.asp
This is how I'd do it in Nokogiri:
require 'nokogiri'
xml = '<objects><object uid="0" /><object uid="1" /><object uid="2" /></objects>'
doc = Nokogiri::XML(xml)
objects_by_uid = doc.search('//object[#uid="2" or #uid="1"]').sort_by { |n| n['uid'].to_i }.reverse
puts objects_by_uid
Running that outputs:
<object uid="2"/>
<object uid="1"/>
An alternative to the search would be:
objects_by_uid = doc.search('//object[#uid="2" or #uid="1"]').sort { |a,b| b['uid'].to_i <=> a['uid'].to_i }
if you don't like using sort_by with the reverse.
XPath is useful for locating and retrieving the nodes but often the filtering we want to do gets too convoluted in the accessor so I let the language do it, whether it's Ruby, Perl or Python. Where I put the filtering logic is based on how big the XML data set is and whether there are a lot of different uid values I'll want to grab. Sometimes letting the XPath engine do the heavy lifting makes sense, other times its easier to let XPath grab all the object nodes and filter in the calling language.

XPath 1 query and attributes name

First question: is there any way to get the name of a node's attributes?
<node attribute1="value1" attribute2="value2" />
Second question: is there a way to get attributes and values as value pairs? The situation is the following:
<node attribute1="10" attribute2="0" />
I want to get all attributes where value>0 and this way: "attribute1=10".
First question: is there any way to
get the name of a node's attributes?
<node attribute1="value1"
attribute2="value2" />
Yes:
This XPath expression (when node is the context (current) node)):
name(#*[1])
produces the name of the first attribute (the ordering may be implementation - dependent)
and this XPath expression (when node is the context (current) node)):
name(#*[2])
produces the name of the second attribute (the ordering may be implementation - dependent).
Second question: is there a way to get
attributes and values as value pairs?
The situation is the following:
<node attribute1="10" attribute2="0"
/>
I want to get all attributes where
value>0 and this way: "attribute1=10".
This XPath expression (when the attribute named "attribute1" is the context (current) node)):
concat(name(), '=', .)
produces the string:
attribute1=value1
and this XPath expression (when the node node is the context (current) node)):
#*[. > 0]
selects all attributes of the context node, whose value is a number, greater than 0.
In XPath 2.0 one can combine them in a single XPath expression:
#*[number(.) > 0]/concat(name(.),'=',.)
to get (in this particular case) this result:
attribute1=10
If you are using XPath 1.0, which is less powerful, you'll need to embed the XPath expression in a hosting language, such as XSLT. The following XSLT 1.0 thransformation :
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text"/>
<xsl:template match="/*">
<xsl:for-each select="#*[number(.) > 0]">
<xsl:value-of select="concat(name(.),'=',.)"/>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
when applied on this XML document:
<node attribute1="10" attribute2="0" />
Produces exactly the same result:
attribute1=10
It depends a little bit on the context, I believe. In most cases, I expect you'd have to query "#*", enumerate over the items, and call "name()" - but it may work in some tests.
Re the edit - you can do:
#*[number(.)>0]
to find attributes matching your criteria, and:
concat(name(),'=',.)
to display the output. I don't think you can do both at once, though. What is the context here? xslt? what?

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