I want to select a node based on the text value of a child.
My structure is as follows (sorry for german nodes):
<InspizierteAbwassertechnischeAnlage>
<Objektbezeichnung>10502002</Objektbezeichnung>
<Anlagentyp>1</Anlagentyp>
</InspizierteAbwassertechnischeAnlage>
How can I select the <InspizierteAbwassertechnischeAnlage> node where e.g. <Objektbezeichnung> = 10502002?
Why your solution didn't work
ancestor:://*[text()='10502002'] is syntactically incorrect, it's not valid XPath. I'm not sure what you tried to do with the axes here.
//*[text()='10502002'] itself would just select the Objektbezeichnung itself and not its parent. It would also select any other element with such a value, regardless of its name. In case of this document, nothing redundant would be returned but you have to be careful when using wildcards (*)
The solution
It's quite simple, you have to use a predicate to inspect the content of the child element
//InspizierteAbwassertechnischeAnlage[Objektbezeichnung = '10502002']
Note the double slash (// ), it is the abbreviated syntax for the descendant-or-self axis. The above expression translates to:
/descendant-or-self::InspizierteAbwassertechnischeAnlage[Objektbezeichnung = '10502002']
Or in plain English
In the set of all descendants of the document's root, find InspizierteAbwassertechnischeAnlage elements that contain at least one Objektbezeichnung element with a value of 10502002
As for German element names, at least it's not Hottentottenstottertrottelmutterbeutelrattenlattengitterkofferattentäter or Rhababerbarbarabarbarbarenbartbarbierbierbarbärbel
Related
While finding the relative XPath via Firebug : it creates like
.//*[#id='Passwd']--------- what if we dont use dot at the start what it signifies?
Just add //* in the Xpath --
it highlights --- various page elements ---------- what does it signify?
Below are XPaths for Gmail password fields. What is significance of * ?
.//*[#id='Passwd']
//child::input[#type='password']
There are several distinct, key XPath concepts in play here...
Absolute vs relative XPaths (/ vs .)
/ introduces an absolute location path, starting at the root of the document.
. introduces a relative location path, starting at the context node.
Named element vs any element (ename vs *)
/ename selects an ename root element
./ename selects all ename child elements of the context node.
/* selects the root element, regardless of name.
./* or * selects all child elements of the context node, regardless of name.
descendant-or-self axis (//*)
//ename selects all ename elements in a document.
.//ename selects all ename elements at or beneath the context node.
//* selects all elements in a document, regardless of name.
.//* selects all elements, regardless of name, at or beneath the context node.
With these concepts in mind, here are answers to your specific questions...
.//*[#id='Passwd'] means to select all elements at or beneath the
context node that have an id attribute value equal to
'Passwd'.
//child::input[#type='password'] can be simplified to
//input[#type='password'] and means to select all input elements
in the document that have an type attribute value equal to 'password'.
These expressions all select different nodesets:
.//*[#id='Passwd']
The '.' at the beginning means, that the current processing starts at the current node. The '*' selects all element nodes descending from this current node with the #id-attribute-value equal to 'Passwd'.
What if we don't use dot at the start what it signifies?
Then you'd select all element nodes with an #id-attribute-value equal to 'Passwd' in the whole document.
Just add //* in the XPath -- it highlights --- various page elements
This would select all element nodes in the whole document.
Below mentioned : XPatht's for Gmail Password field are true what is significance of * ?
.//*[#id='Passwd']
This would select all element nodes descending from the current node which #id-attribute-value is equal to 'Passwd'.
//child::input[#type='password']
This would select all child-element nodes named input which #type-attribute-values are equal to 'password'. The child:: axis prefix may be omitted, because it is the default behaviour.
The syntax of choosing the appropriate expression is explained here at w3school.com.
And the Axes(current point in processing) are explained here at another w3school.com page.
The dot in XPath is called a "context item expression". If you put a dot at the beginning of the expression, it would make it context-specific. In other words, it would search the element with id="Passwd" in the context of the node on which you are calling the "find element by XPath" method.
The * in the .//*[#id='Passwd'] helps to match any element with id='Passwd'.
For the first question: It's all about the context. You can see Syntax to know what '.', '..' etc means. Also, I bet you won't find any explanation better than This Link.
Simplified answer for second question: You would generally find nodes using the html tags like td, a, li, div etc. But '*' means, find any tag that match your given property. It's mostly used when you are sure about a given property but not about that tag in which the element might come with, like suppose I want a list of all elements with ID 'xyz' be it in any tag.
Hope it helps :)
Here is my XML file:
<w type="fruit-hard">apple</w>
<w type="fruit-soft">orange</w>
<w type="vegetable">carrot</w>
I need to find carrot's immediately preceding sibling whose type is fruit-soft. In Chrome (locally loaded XML file), when I try
$x("//w[#type='vegetable']/preceding-sibling::w[1]")
I get "orange" element node like I want, but how do I require that its type be "fruit-soft"? My attempt (below) returns "false."
$x("//w[#type='vegetable']/preceding-sibling::w[1] and preceding-sibling::w[#type='fruit-soft']")
Your original XPath ...
//w[#type='vegetable']/preceding-sibling::w[1]
... is equivalent to
//w[#type='vegetable']/preceding-sibling::w[position()=1]
. You can add additional criteria to the predicate as needed:
//w[#type='vegetable']/preceding-sibling::w[position()=1 and #type='fruit-soft']
Or you can add an add a separate predicate
//w[#type='vegetable']/preceding-sibling::w[1][#type='fruit-soft']
Note that this attempt:
//w[#type='vegetable']/preceding-sibling::w[1] and preceding-sibling::w[#type='fruit-soft']
returns false because the parts on either side of the and are evaluated separately, converted to type boolean, and combined to yield the final result. Supposing that the context node against which that is evaluated is the document root, there will never be a node matching preceding-sibling::w[#type='fruit-soft']. Moreover, even if there were such a node, that expression does not require nodes matching the first part to be the same ones that matches the second part.
I am trying to back to to previous td but to no avail, can you help
//*[#class='ein' and contains(.,'aaaa')] gets me to td but need to select the previous td-tried below but did not work
//*[#class='ein' and contains(.,'aaaa')][preceding-sibling::td]
Remember /X means "select X", while [X] means "where X". If you want to select preceding siblings, rather than testing whether they exist, use /.
It's impossible to say for certain without seeing the input HTML but I suspect that instead of
//*[#class='ein' and contains(.,'aaaa')][preceding-sibling::td]
you need something like
//*[#class='ein' and contains(.,'aaaa')]/preceding-sibling::td[1]
to navigate from each node selected by the initial expression to its nearest preceding td. Your first attempt will select exactly the same nodes as
//*[#class='ein' and contains(.,'aaaa')]
but only if they have at least one preceding-sibling element named td.
Use // after the element you found
Instead of preceding-sibling, just use preceding
//*[#class='ein' and contains(.,'aaaa')]//preceding::td[1]
I have those two RxPaths which I need to be written in one expresion:
/td[2]/a[1]/tag[1]
and
/td[2]/a[1]
So basically I need to select path with 'tag' element if exists, if not than to select 'a' element.
something like:
if exist /td[2]/a[1]/tag[1] select /td[2]/a[1]/tag[1]
else select /td[2]/a[1]
Those elements need to have innertext attribute with some value in them, so I tried:
/td[2]/descendant::node()[#innertext!='']
but it won't work...
Also those elements are at the bottom of hierarchy so if is there any way to just select first element at lowest level.
I managed to solve this with an regex at the end of my Xpath expression.
/dom/body/div[#id='isc_0']/div/div[#id='isc_B']/div[#id='isc_C']/div[#id='isc_10']/div/div/iframe/body/table/tbody/tr/td[1]/a[#innertext='any uri item']/../../td[2]/*[#innertext~'[^ ]+']
Sorry for misunderstanding with problem...
Regards,
Vajda Vladimir
So basically I need to select path
with 'tag' element if exists, if not
than to select 'a' element. something
like:
if exist
/td[2]/a[1]/tag[1]
select
/td[2]/a[1]/tag[1]
else select
/td[2]/a[1]
I highly doubt that the top element of the document is a td. Don't use /td -- it means you want to select the top element of the document and this top element must be a td .
Also, /td[2] never selects anything, because a (wellformed) XML document has exactly one top element.
Use:
someParentElement/td[2]/a[1]/tag[1]
|
someParentElement/td[2]/a[1][not(someParentElement/td[2]/a[1]/tag[1])]
Those elements need to have innertext
attribute with some value in them
Use:
someParentElement/td[2][.//#innertext[normalize-space()]]/a[1]/tag[1]
|
someParentElement/td[2]
[.//#innertext[normalize-space()]]/a[1]
[not(someParentElement/td[2]
[.//#innertext[normalize-space()]]/a[1]/tag[1])]
Also those elements are at the bottom
of hierarchy so if is there any way to
just select first element at lowest
level.
This is not clear. Please, clarify.
All "leaf" elements can be selected using the following XPath expression:
//*[not(*)]
The elements selected don't have any children-elements, but may have other children (such as text-nodes, PIs, comments) and attributes.
Besides all those good advices from #Dimitre, I want to add that a parent will always come before (in document order) than a child, so you could use this XPath expression:
(/real-path-from-root/td[2]/a[1]
|
/real-path-from-root/td[2]/a[1]/tag[1])[last()]
You could do this without | union set operator in XPath 1.0, but it will end up very unreadable... Of course, in XPath 2.0 you could just do:
(/real-path-from-root/td[2]/a[1]/(.|tag[1]))[last()]
I have an XPath that returns two items. I want to modify it so that it returns only the second, or the last if there are more than 2.
//a[#rel='next']
I tried
//a[#rel='next'][2]
but that doesn't return anything at all. How can I rewrite the xpath so I get only the 2nd link?
Found the answer in
XPATH : finding an attribute node (and only one)
In my case the right XPath would be
(//a[#rel='next'])[last()]
EDIT (by Tomalak) - Explanation:
This selects all a[#rel='next'] nodes, and takes the last of the entire set:
(//a[#rel='next'])[last()]
This selects all a[#rel='next'] nodes that are the respective last a[#rel='next'] of the parent context each of them is in:
//a[#rel='next'][last()] equivalent: //a[#rel='next' and position()=last()]
This selects all a[#rel='next'] nodes that are the second a[#rel='next'] of the parent context each of them is in (in your case, each parent context had only one a[#rel='next'], that's why you did not get anything back):
//a[#rel='next'][2] equivalent: //a[#rel='next' and position()=2]
For the sake of completeness: This selects all a nodes that are the last of the parent context each of them is in, and of them only those that have #rel='next' (XPath predicates are applied from left to right!):
//a[last()][#rel='next'] NOT equiv!: //a[position()=last() and #rel='next']