<td _ngcontent-wp class="align-middle">
"4.79728"
<small _ngcontent-wp class="neo_red_dark"> -0.08% </small>
</td>
My XPath as follows:
(//table[#class="table"]/tbody/tr/td[3])[1]
It works, but it gets two values together (4.79728 -0.08%). How can I get them separately?
You can get the value before the space and after the space using:
substring-before() and substring-after()
or change your XPath to target the text() descendants of the td instead of the td itself (which is producing the calculated text value).
In order to select "4.79728":
(//table[#class="table"]/tbody/tr/td[3])[1]/text()
In order to select -0.08%:
(//table[#class="table"]/tbody/tr/td[3])[1]/small/text()
You should indicate with XPath questions which XPath version you are using.
If it's version 1.0, remember that the set of data types you can return is very limited: a single string, number, or boolean, or a node-set. And some APIs only allow you to return a node-set.
Your current query is returning a node-set containing one node, namely a td element, whose string value contains the concatenation of all the text within. You could return a node-set containing all the text nodes individually by appending //text() to the query. But of course, it won't always be the case that the two numbers are in separate text nodes.
Related
Let's say I have a piece of HTML like this:
<a>Ask Question<other/>more text</a>
I can match this piece of XPath:
//a[text() = 'Ask Question']
Or...
//a[text() = 'more text']
Or I can use dot to match the whole thing:
//a[. = 'Ask Questionmore text']
This post describes this difference between . (dot) and text(), but in short the first returns a single element, where the latter returns a list of elements. But this is where it gets a bit weird to me. Because while text() can be used to match either of the elements on the list, this is not the case when it comes to the XPath function contains(). If I do this:
//a[contains(text(), 'Ask Question')]
...I get the following error:
Error: Required cardinality of first argument of contains() is one or zero
How can it be that text() works when using a full match (equals), but doesn't work on partial matches (contains)?
For this markup,
<a>Ask Question<other/>more text</a>
notice that the a element has a text node child ("Ask Question"), an empty element child (other), and a second text node child ("more text").
Here's how to reason through what's happening when evaluating //a[contains(text(),'Ask Question')] against that markup:
contains(x,y) expects x to be a string, but text() matches two text nodes.
In XPath 1.0, the rule for converting multiple nodes to a string is this:
A node-set is converted to a string by returning the string-value of
the node in the node-set that is first in document order. If the
node-set is empty, an empty string is returned. [Emphasis added]
In XPath 2.0+, it is an error to provide a sequence of text nodes to a function expecting a string, so contains(text(),'substr') will cause an error for more than one matching text node.
In your case...
XPath 1.0 would treat contains(text(),'Ask Question') as
contains('Ask Question','Ask Question')
which is true. On the other hand, be sure to notice that contains(text(),'more text') will evaluate to false in XPath 1.0. Without knowing the (1)-(3) above, this can be counter-intuitive.
XPath 2.0 would treat it as an error.
Better alternatives
If the goal is to find all a elements whose string value contains the substring, "Ask Question":
//a[contains(.,'Ask Question')]
This is the most common requirement.
If the goal is to find all a elements with an immediate text node child equal to "Ask Question":
//a[text()='Ask Question']
This can be useful when wishing to exclude strings from descendent elements in a such as if you want this a,
<a>Ask Question<other/>more text</a>
but not this a:
<a>more text before <not>Ask Question</not> more text after</a>
See also
How contains() handles a nodeset first arg
How to use XPath contains() for specific text?
Testing text() nodes vs string values in XPath
The reason for this is that the contains function doesn't accept a nodeset as input - it only accepts a string. (Well, it may be engine dependent, because it works for Python's lxml module. According to the specification, it should convert the value of the first node in the set to a string and act on that. See also XPath contains(text(),'some string') doesn't work when used with node with more than one Text subnode)
//a[text() = 'Ask Question'] is matching any a elements which contain a text node which equals Ask Question.
//a[text() = 'more text'] is matching any a elements which contain a text node which equals more text.
So both of these expressions match the same a element.
You can re-work your query to //a[text()[contains(., 'Ask Question')]] so that the contains method will only act on a single text node at a time.
I'm trying to identify an element that has certain text but I only want to identify the element if the desired text occurs a specific number of times.
For example, imagine we have the following two HTML snippets on the same page:
Snippet 1:
<span id="price">
$36.46
<span>
($0.38 / Count)
</span>
</span>
Snippet 2:
<span id="price">$38.38</span>
I could identify both elements using the XPath: .//span[contains(text(),'$')] However, I only want to identify the element if it (or any descendant of span element) contain at least two instances of the character: $
In above example, it would only identify the first snippet because the second snippet only contains one instance of $, not two.
What is the correct XPath syntax to use?
You can use the XPath //span[count(.//text()[contains(., "$")]) >= 2]
This is a moderately complicated XPath, so to explain it some by expanding outwards:
.//text()[contains(., "$")]
Select all text elements descending from the current node whose self contains "$".
count(.//text()[contains(., "$")])
Count the number of text elements descending from the current node whose self contains "$".
//span[count(.//text()[contains(., "$")]) >= 2]
Select all span elements with two or more text descendants whose self contains "$"
As a caveat, this only works if the dollar sign is in two different text elements. If you want to include the span in this example:
<span>
$$
<span>
foo
</span>
</span>
...then you'll need a different approach:
//span[string-length(.) - string-length(translate(., "$", "")) >= 2]
This predicate compares the string length of the span to the string length of the same span with all "$" characters removed.
One usable XPath-1.0 expression is
string-length(/span[#id='price'])-string-length(translate(/span[#id='price'],'$',''))
In a predicate this could look like
//span[string-length(.)-string-length(translate(.,'$',''))>=2]
This expression selects only the elements with a count of $ >= 2
I want to extract elements from the HTML page, containing text, ignoring markup. For example, I want to extract node containing the text "Run, Sarah, run!" from https://en.wiktionary.org/wiki/run. I know about node test text() and function string(). I tried them both:
As you see, if I use string() it returns too many nodes (result includes the nodes that include the node I need) and if I use text() it returns nothing (because of the <b> tag).
How do I find required nodes?
UPD: I want all deepest nodes. That means if the Wikitionary page contained this sentence twice, I wanted to select two nodes.
Also, I don't know the node type.
//*[contains(string(.), "Run, Sarah, run!")] returns all elements (starting from html node till last descendant node) that contains that string.
//*[contains(text(), "Run, Sarah, run!")] returns nothing as "Run, Sarah, run!" is compound text from several text nodes, but not from single text node
You can use below to match italic node with required text:
'//i[normalize-space()="Run, Sarah, run!"]'
If you don't want to specify node name, you can try
'//*[normalize-space()="Run, Sarah, run!" and not(./*[normalize-space()="Run, Sarah, run!"])]'
This is the HTML code:
<div> <span></span> Elangovan </div>
I want to write an XPath for the div based on its contained text. I tried
//div[contains(text(),'Elangovan')]
but this is not working.
Replace text() with string():
//div[contains(string(), "Elangovan")]
Or, you can check that span's following text sibling contains the text:
//div[contains(span/following-sibling::text(), "Elangovan")]
Also see:
Difference between text() and string()
Alternatively to alecxe's correct answer (+1), the following slightly simpler and somewhat more idiomatic XPath will work the same way:
//div[contains(., "Elangovan")]
The reason that your original XPath with text() does not work is that text() will select all text node children of div. However, contains() expects a string in its first argument, and when given a node set of text nodes, it only uses the first one. Here, the first text node contains whitespace, not the sought after string, so the test fails. With the implicit . or the explicit string() first argument, all text node descendants are concatenated together before performing the contains() test, so the test passes.
To make #kjhughes's already good answer just a little more precise, what you're really asking for is a way to look for substrings in the div's string-value:
For every type of node, there is a way of determining a string-value
for a node of that type. For some types of node, the string-value is
part of the node; for other types of node, the string-value is
computed from the string-value of descendant nodes.
Both the context node (. or the div itself) and the set of nodes returned by text() -- or any other argument! -- are first converted to strings when passed to contains. It's just that they're converted in different ways, because one refers to a single element and the other refers to a node-set.
A single element's string-value is the concatenation of the string-values of all its text node descendants. A node-set's string-value, on the other hand, is the string-value of the node in the set that is first in document order.
So the real difference is in what you're converting to a string and how that conversion takes place.
I want to scrape the post name, which for pattern one it's located within a span
but the forum thread can goes like this (line 7)
because the thread is a poll.
so in my case I can't target the span (line 8 first picture), I used descendants-or-self but hardly to get it right. What's wrong here?
$postTitle = $xpath->query("//tr/td[#class='row1'][3]/div/div[1]//descendant-or-self::text()");
With this expression you will select the first <a> in the <div> where the text you wish to extract is located:
//tr/td[#class='row1'][3]/div/div[1]/a[1]
I'm assuming you intend to select one element (and not a node-set). For that you can get the string-value of this expression (which will return all the text in the descendant nodes) using string() or normalize-space() (which trims and removes extra spaces):
normalize-space(//tr/td[#class='row1'][3]/div/div[1]/a[1])
This will extract Salary vs age or /ktards are you... depending on the node found.
If there is more than one match it will return a collection, which you should iterate over and get the string value of each one individually. Using those functions on a node-set will give you the text in the first element, discarding the others.
If you only have to deal with two cases: 1) text inside a/span, 2) text inside a, you can select the text nodes directly using a union (|) operator:
//tr/td[#class='row1'][3]/div/div[1]/a[1]/text() | //tr/td[#class='row1'][3]/div/div[1]/a[1]/span/text()