I was selecting all attributes id and everything was going nicely then one day requirements changed and now I have to select all except one!
Given the following example:
<root>
<structs id="123">
<struct>
<comp>
<data id="asd"/>
</comp>
</struct>
</structs>
</root>
I want to select all attributes id except the one at /root/structs/struct/comp/data
Please note that the Xml could be different.
Meaning, what I really want is: given any Xml tree, I want to select all attributes id except the one on element /root/structs/struct/comp/data
I tried the following:
//#id[not(ancestor::struct)] It kinda worked but I want to provide a full xpath to the ancestor axis which I couldn't
//#id[not(contains(name(), 'data'))] It didn't work because name selector returns the name of the underlying node which is the attribute not its parent element
The following should achieve what you're describing:
//#id[not(parent::data/parent::comp/parent::struct/parent::structs/parent::root)]
As you can see, it simply checks from bottom to top whether the id attribute's parent matches the path root/structs/struct/comp/data.
I think this should be sufficient for your needs, but it does not 100% ensure that the parent is at the path /root/structs/struct/comp/data because it could be, for example, at the path /someOtherHigherRoot/root/structs/struct/comp/data. I'm guessing that's not a possible scenario in your XML structure, but if you had to check for that, you could do this:
//#id[not(parent::data/parent::comp/parent::struct/parent::structs/parent::root[not(parent::*)])]
Related
I have the following XML structure
<Root>
<BundleItem>
<Item>1</Item>
<Item>2</Item>
<Item>3</Item>
</BundleItem>
<Item>4</Item>
<Item>5</Item>
<Item>6</Item>
<BundleItem>
<Item>7</Item>
<Item>8</Item>
<Item>9</Item>
</BundleItem>
</Root>
And by providing the following xPath
//Item[1]
I am selecting
<Item>1</Item>
<Item>4</Item>
<Item>7</Item>
My goal is to select only <Item>1</Item> or <Item>7</Item> regardless of the parent element where they are found and only depending on the position, which i am providing in the xPath.
Is it possible to do that only by using the position and without providing additional criterias in the xPath ?
//Item[1] selects the all the first child elements that are <Item/> regardless of their parent.
To get the two items you are looking for you could use //Item[text() = 1 or text() = 7].
A good tutorial can be found at w3schools.com and you can play with XPath expressions over your XML input here. (I am not affiliated with either of these resources but find them useful.)
Edit: I think I found the answer but I'll leave the open for a bit to see if someone has a correction/improvement.
I'm using xpath in Talend's etl tool. I have xml like this:
<root>
<employee>
<benefits>
<benefit>
<benefitname>CDE</benefitname>
<benefit_start>2/3/2004</benefit_start>
</benefit>
<benefit>
<benefitname>ABC</benefitname>
<benefit_start>1/1/2001</benefit_start>
</benefit>
</benefits>
<dependent>
<benefits>
<benefit>
<benefitname>ABC</benefitname>
</benefit>
</dependent>
When parsing benefits for dependents, I want to get elements present in the employee's
benefit element. So in the example above, I want to get 1/1/2001 for the dependent's
start date. I want 1/1/2001, not 2/3/2004, because the dependent's benefit has benefitname ABC, matching the employee's benefit with the same benefitname.
What xpath, relative to /root/employee/dependent/benefits/benefit, will yield the value of
benefit_start for the benefit under parent employee that has the same benefit name as the
dependent benefit name? (Note I don't know ahead of time what the literal value will be, I can't just look for 'ABC', I have to match whatever value is in the dependent's benefitname element.
I'm trying:
../../../benefits/benefit[benefitname=??what??]/benefit_start
I don't know how to refer to the current node's ancestor in the middle of
the xpath (since I think "." at the point I have ??what?? will refer to
the benefit node of the employee/benefits.
EDIT: I think what I want is "current()/benefitname" where the ??what?? is. Seems to work with saxon, I haven't tried it in the etl tool yet.
Your XML is malformed, and I don't think you've described your siduation very well (the XPath you're trying has a bunch of ../../s at the beginning, but you haven't said what the context node is, whether you're iterating through certain nodes, or what.
Supposing the current context node were an employee element, you could select benefit_starts that match dependent benefits with
benefits/benefit[benefitname = ../../dependent/benefits/benefit/benefitname]
/benefit_start
If the current context node is a benefit element in a dependents section, and you want to get the corresponding benefit_start for just the current benefit element, you can do:
../../../benefits/benefit[benefitname = current()/benefitname]/benefit_start
Which is what I think you've already discovered.
I have several nodes with some particular attribute and I need to select one of them by index. For example I need to select second <div> with 'test' class - //div[#class='test'][2] doesn't work.
Is there a way to select node with some attribute by index ? How to do it?
This is a FAQ.
In XPath the [] operator has a higher precedence (binds stronger) than the // pseudo-operator.
Because of this, the expression:
//div[#class='test'][2]
selects all div elements whose class attribute is "test" and who (the div elements) are the second such div child of their parent. This is not what you want.
Use:
(//div[#class='test'])[2]
I believe per XML specification, attributes are not considered to have an order.
Note that the order of attribute specifications in a start-tag or empty-element tag is not significant.
See here
I think you'd be best of re-factoring your structure such that attribute order does not describe anything. If you can give any more details we might be able to offer suggestions.
EDIT: Re-reading your post, looks like you are trying to find node order and not attribute order. Node order is allowed and your syntax looks OK off-hand. What software are you doing this in?
I am looking to find all attributes of an element that match a certain pattern.
So for an element
<element s2="1" name="aaaa" id="1" />
<element s3="1" name="aaaa" id="2" />
I would like to be able to find all attributes that start with 's' (returning the value of s1 for the first element and s3 for the value of the second element).
If this is outside of xpath's ability please let me know.
Use:
element/#*[starts-with(name(), 's')]
This XPath expression selects all atribute nodes whose name starts with the string 's' and that are attributes of elements named element that are children of the current node.
starts-with() is a standard function in XPath 1.0
element/#*[substring(name(), 1,1) = "s"]
will match any attribute that starts with 's'.
The function starts-with() might look better than using substring()
I've tested the given answers from both #Dimitre-Novatchev and #Ledhund, using lxml.html module in Python.
Both element/#*[starts-with(name(), 's')] and element/#*[substring(name(), 1,1) = "s"] return only the values of s2 and s3. You won't be able to know which value belong to which attribute.
I think in practice I would be more interested in finding the elements themselves that contain the attributes of names starting with specific characters rather than just their values.
To achieve that is very simple, just add /.. at the end,
element/#*[starts-with(name(), "s")]/..
or
element/#*[starts-with(name(), "s")]/parent::*
or
element/#*[starts-with(name(), "s")]/parent::node()
None from above worked for me.
So I did not some changes and it worked for me. :)
/*:UserCustomField[starts-with(#name, 'purchaseDate')]
When I have 2 set of nodes with same element name for ex :
<contacts>
<names>
...
</names>
<names>
...
</names>
</contacts>
Normally I'd use //contacts/names to get the node, but how do I do if they have the same name how do I get second or first or nth?
For the provided XML document use:
/contacts/names[1]
the above selects the first names element.
/contacts/names[2]
the above selects the second names element.
Try to avoid using the // abbreviation as much as possible, because it is usually grossly inefficient, causes all the (sub)tree roted in the context node to be traversed.
You can do this to get the first and/or second specifically:
//contacts/names[1]
//contacts/names[2]
Use //contacts/names[n] to get the nth names node. For example: //contacts/names[1] gets the first names node while //contacts/names[2] gets the second names node, etc.