Testing

Xpath test bed

Test queries in the Xpath test bed:

Browser console

$x("//div")

Works in Firefox and Chromium browsers.

Selectors

Descendant selectors

CSSXpath?
h1//h1?
div p//div//p?
ul > li//ul/li?
ul > li > a//ul/li/a 
div > *//div/* 
:root/?
:root > body/body 

Attribute selectors

CSSXpath?
#id//*[@id="id"]?
.class//*[@class="class"] ...kinda 
input[type="submit"]//input[@type="submit"] 
a#abc[for="xyz"]//a[@id="abc"][@for="xyz"]?
a[rel]//a[@rel] 
a[href^='/']//a[starts-with(@href, '/')]?
a[href$='pdf']//a[ends-with(@href, '.pdf')] 
a[href*='://']//a[contains(@href, '://')] 
a[rel~='help']//a[contains(@rel, 'help')] ...kinda 

Order selectors

CSSXpath?
ul > li:first-of-type//ul/li[1]?
ul > li:nth-of-type(2)//ul/li[2] 
ul > li:last-of-type//ul/li[last()] 
li#id:first-of-type//li[1][@id="id"]?
a:first-child//*[1][name()="a"] 
a:last-child//*[last()][name()="a"] 

Siblings

CSSXpath?
h1 ~ ul//h1/following-sibling::ul?
h1 + ul//h1/following-sibling::ul[1] 
h1 ~ #id//h1/following-sibling::[@id="id"] 

jQuery

CSSXpath?
$('ul > li').parent()//ul/li/..?
$('li').closest('section')//li/ancestor-or-self::section 
$('a').attr('href')//a/@href?
$('span').text()//span/text() 

Other things

CSSXpath?
h1:not([id])//h1[not(@id)]?
Text match//button[text()="Submit"]?
Text match (substring)//button[contains(text(),"Go")] 
Arithmetic//product[@price > 2.50] 
Has children//ul[*] 
Has children (specific)//ul[li] 
Or logic//a[@name or @href]?
Union (joins results)//a | //div?

Class check

//div[contains(concat(' ',normalize-space(@class),' '),' foobar ')]

Xpath doesn't have the "check if part of space-separated list" operator, so this is the workaround (source).

Expressions

Steps and axes

AxisStepAxisStep
//ul/a[@id='link']
AxisStepAxisStep

Prefixes

PrefixExampleWhat
////hr[@class='edge']Anywhere
././aRelative
//html/body/divRoot

Begin your expression with any of these.

Axes

AxisExampleWhat
///ul/li/aChild
////[@id="list"]//aDescendant

Separate your steps with /. Use two (//) if you don't want to select direct children.

Steps

//div
//div[@name='box']
//[@id='link']

A step may have an element name (div) and predicates ([...]). Both are optional. They can also be these other things:

//a/text()     #=> "Go home"
//a/@href      #=> "index.html"
//a/*          #=> All a's child elements

Predicates

Predicates

//div[true()]
//div[@class="head"]
//div[@class="head"][@id="top"]

Restricts a nodeset only if some condition is true. They can be chained.

Operators

# 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 comparison and logic operators to make conditionals.

Using nodes

# Use them inside functions
//ul[count(li) > 2]
//ul[count(li[@class='hide']) > 0]

# This returns `
    ` that has a `
  • ` child
//ul[li]

You can use nodes inside predicates.

Indexing

//a[1]                  # first 
//a[last()]             # last 
//ol/li[2]              # second 
  • 
//ol/li[position()=2]   # same as above
//ol/li[position()>1]   # :not(:first-of-type)

    • Use [] with a number, or last() or position().

    Chaining order

    a[1][@href='/']
a[@href='/'][1]

    Order is significant, these two are different.

    Nesting predicates

    //section[.//h1[@id='hi']]

    This returns

    if it has an

    descendant with id='hi'.

    Functions

    Node functions

    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]

    Boolean functions

    not(expr)                  # button[not(starts-with(text(),"Submit"))]

    String functions

    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()

    Type conversion

    string()
number()
boolean()

    Axes

    Using axes

    //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')

    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 ::.

    AxisStepAxisStep
    //ul/child::li
    AxisStepAxisStep

    Child axis

    # 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, so the predicate succeeds
//ul[li]
//ul[child::li]

    # both the same
//ul[count(li) > 2]
//ul[count(child::li) > 2]

    Descendant-or-self axis

    # 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()]

    Other axes

    AxisAbbrevNotes
    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  

    There are other axes you can use.

    Unions

    //a | //span

    Use | to join two expressions.

    More examples

    Examples

    //*                 # all elements
count(//*)          # count all elements
(//h1)[1]/text()    # text of the first h1 heading
//li[span]          # find a 
  •  with an  inside it
                    # ...expands to //li[child::span]
//ul/li/..          # use .. to select a parent

    • Find a parent

    //section[h1[@id='section-name']]

    Finds a

    that directly contains h1#section-name

    //section[//h1[@id='section-name']]

    Finds a

    that contains h1#section-name. (Same as above, but uses descendant-or-self instead of child)

    Closest

    ./ancestor-or-self::[@class="box"]

    Works like jQuery's $().closest('.box').

    Attributes

    //item[@price > 2*@discount]

    Finds and check its attributes

    References

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