title: XPath date: 2020-12-19 22:15:43 background: bg-[#77aeeb] tags: - document - expression - select categories: - Toolkit intro: |
Test in Firefox or Chrome console:
$x('/html/body')
$x('//h1')
$x('//h1')[0].innerText
$x('//a[text()="XPath"]')[0].click()
Xpath | CSS |
---|---|
//h1 |
h1 |
//div//p |
div p |
//ul/li |
ul > li |
//ul/li/a |
ul > li > a |
//div/* |
div > * |
/ |
:root |
/html/body |
:root > body |
{.show-header}
Xpath | CSS |
---|---|
//ul/li[1] |
ul > li:first-child |
//ul/li[2] |
ul > li:nth-child(2) |
//ul/li[last()] |
ul > li:last-child |
//li[@id="id"][1] |
li#id:first-child |
//a[1] |
a:first-child |
//a[last()] |
a:last-child |
{.show-header}
Xpath | CSS |
---|---|
//*[@id="id"] |
#id |
//*[@class="class"] |
.class |
//input[@type="submit"] |
input[type="submit"] |
//a[@id="abc"][@for="xyz"] |
a#abc[for="xyz"] |
//a[@rel] |
a[rel] |
//a[starts-with(@href, '/')] |
a[href^='/'] |
//a[ends-with(@href, '.pdf')] |
a[href$='pdf'] |
//a[contains(@href, '://')] |
a[href*=': //'] |
//a[contains(@rel, 'help')] |
a[rel~='help'] |
{.show-header}
Xpath | CSS |
---|---|
//h1/following-sibling::ul |
h1 ~ ul |
//h1/following-sibling::ul[1] |
h1 + ul |
//h1/following-sibling::[@id="id"] |
h1 ~ #id |
{.show-header}
Xpath | CSS |
---|---|
//ul/li/.. |
$('ul > li').parent() |
//li/ancestor-or-self::section |
$('li').closest('section') |
//a/@href |
$('a').attr('href') |
//span/text() |
$('span').text() |
{.show-header}
Xpath | CSS |
---|---|
//h1[not(@id)] |
h1:not([id]) |
//button[text()="Submit"] |
Text match |
//button[contains(text(),"Go")] |
Text contains (substring) |
//product[@price > 2.50] |
Arithmetic |
//ul[*] |
Has children |
//ul[li] |
Has children (specific) |
//a[@name or @href] |
Or logic |
//a | //div |
Union (joins results) |
{.show-header}
------ | ------ | ------ | ----------------- |
// |
ul |
/ |
a[@id='link'] |
Axis | Step | Axis | Step |
{.left-text}
Prefix | Example | Means |
---|---|---|
// |
//hr[@class='edge'] |
Anywhere |
/ |
/html/body/div |
Root |
./ |
./div/p |
Relative |
{.show-header}
Axis | Example | Means |
---|---|---|
/ |
//ul/li/a |
Child |
// |
//[@id="list"]//a |
Descendant |
{.show-header}
//div[true()]
//div[@class="head"]
//div[@class="head"][@id="top"]
Restricts a nodeset only if some condition is true. They can be chained.
# Comparison
//a[@id = "xyz"]
//a[@id != "xyz"]
//a[@price > 25]
# Logic (and/or)
//div[@id="head" and position()=2]
//div[(x and y) or not(z)]
# Use them inside functions
//ul[count(li) > 2]
//ul[count(li[@class='hide']) > 0]
# Returns `<ul>` that has a `<li>` child
//ul[li]
You can use nodes inside predicates.
//a[1] # first <a>
//a[last()] # last <a>
//ol/li[2] # second <li>
//ol/li[position()=2] # same as above
//ol/li[position()>1] #:not(:first-child)
Use []
with a number, or last()
or position()
.
a[1][@href='/']
a[@href='/'][1]
Order is significant, these two are different.
//section[.//h1[@id='hi']]
This returns <section>
if it has an <h1>
descendant with id='hi'
.
name() # //[starts-with(name(), 'h')]
text() # //button[text()="Submit"]
# //button/text()
lang(str)
namespace-uri()
count() # //table[count(tr)=1]
position() # //ol/li[position()=2]
contains() # font[contains(@class,"head")]
starts-with() # font[starts-with(@class,"head")]
ends-with() # font[ends-with(@class,"head")]
concat(x,y)
substring(str, start, len)
substring-before("01/02", "/") #=> 01
substring-after("01/02", "/") #=> 02
translate()
normalize-space()
string-length()
not(expr) # button[not(starts-with(text(),"Submit"))]
string()
number()
boolean()
//ul/li # ul > li
//ul/child::li # ul > li (same)
//ul/following-sibling::li # ul ~ li
//ul/descendant-or-self::li # ul li
//ul/ancestor-or-self::li # $('ul').closest('li')
// |
ul |
/child:: |
li |
Axis | Step | Axis | Step |
{.left-text}
Steps of an expression are separated by /
, usually used to pick child nodes. That's not always true: you can specify a different "axis" with ::
.
# both the same
//ul/li/a
//child::ul/child::li/child::a
child::
is the default axis. This makes //a/b/c
work.
# both the same
# this works because `child::li` is truthy
//ul[li]
//ul[child::li]
# both the same
//ul[count(li) > 2]
//ul[count(child::li) > 2]
# both the same
//div//h4
//div/descendant-or-self::h4
//
is short for the descendant-or-self::
axis.
# both the same
//ul//[last()]
//ul/descendant-or-self::[last()]
Axis | Abbrev | Notes |
---|---|---|
ancestor |
||
ancestor-or-self |
| attribute
| @
| @href
is short for attribute::href
|
| child
| | div
is short for child::div
|
| descendant
| | |
| descendant-or-self
| //
| //
is short for /descendant-or-self::node()/
|
| namespace
| | |
| self
| .
| .
is short for self::node()
|
| parent
| ..
| ..
is short for parent::node()
|
| following
| | |
| following-sibling
| | |
| preceding
| | |
| preceding-sibling
| | |
{.headers}
There are other axes you can use.
//a | //span
Use |
to join two expressions.
//* # all elements
count(//*) # count all elements
(//h1)[1]/text() # text of the first h1 heading
//li[span] # find a <li> with an <span> inside it
# ...expands to //li[child::span]
//ul/li/.. # use .. to select a parent
//section[h1[@id='section-name']]
Finds a <section>
that directly contains h1#section-name
//section[//h1[@id='section-name']]
Finds a <section>
that contains h1#section-name
.
(Same as above, but uses descendant-or-self instead of child)
./ancestor-or-self::[@class="box"]
Works like jQuery's $().closest('.box')
.
//item[@price > 2*@discount]
Finds <item>
and check its attributes