6.0 KiB
Selector engines
Playwright supports multiple selector engines used to query elements in the web page.
Selector can be used to obtain ElementHandle
(see page.$() for example) or shortcut element operations to avoid intermediate handle (see page.click() for example).
Selector syntax
Selector is a string that consists of one or more clauses separated by >>
token, e.g. clause1 >> clause2 >> clause3
. When multiple clauses are present, next one is queried relative to the previous one's result.
Each clause contains a selector engine name and selector body, e.g. engine=body
. Here engine
is one of the supported engines (e.g. css
or a custom one). Selector body
follows the format of the particular engine, e.g. for css
engine it should be a css selector. Body format is assumed to ignore leading and trailing whitespaces, so that extra whitespace can be added for readability. If selector engine needs to include >>
in the body, it should be escaped inside a string to not be confused with clause separator, e.g. text="some >> text"
.
For example,
css=article >> css=.bar > .baz >> css=span[attr=value]
is equivalent to
document
.querySelector('article')
.querySelector('.bar > .baz')
.querySelector('span[attr=value]')
For convenience, selectors in the wrong format are heuristically converted to the right format:
- selector starting with
//
is assumed to bexpath=selector
; - selector starting with
"
is assumed to betext=selector
; - otherwise selector is assumed to be
css=selector
.
Examples
// queries 'div' css selector
const handle = await page.$('css=div');
// queries '//html/body/div' xpath selector
const handle = await page.$('xpath=//html/body/div');
// queries '"foo"' text selector
const handle = await page.$('text="foo"');
// queries 'span' css selector inside the result of '//html/body/div' xpath selector
const handle = await page.$('xpath=//html/body/div >> css=span');
// converted to 'css=div'
const handle = await page.$('div');
// converted to 'xpath=//html/body/div'
const handle = await page.$('//html/body/div');
// converted to 'text="foo"'
const handle = await page.$('"foo"');
// queries 'span' css selector inside the div handle
const handle = await divHandle.$('css=span');
Built-in selector engines
css
CSS engine is equivalent to Document.querySelector
. Example: css=.article > span:nth-child(2) li
.
Note
Malformed selector not starting with
//
nor with#
is automatically transformed to css selector. For example, Playwright convertspage.$('span > button')
topage.$('css=span > button')
. Selectors starting with#
are converted to text. Selectors starting with//
are converted to xpath.
xpath
XPath engine is equivalent to Document.evaluate
. Example: xpath=//html/body
.
Note
Malformed selector starting with
//
is automatically transformed to xpath selector. For example, Playwright convertspage.$('//html/body')
topage.$('xpath=//html/body')
.
text
Text engine finds an element that contains a text node with passed text. Example: text=Login
.
- By default, the match is case-insensitive, and ignores leading/trailing whitespace. This means
text= Login
matches<button>loGIN </button>
. - Text body can be escaped with double quotes for precise matching, insisting on specific whitespace and case. This means
text="Login "
will only match<button>Login </button>
with exactly one space after "Login". - Text body can also be a JavaScript-like regex wrapped in
/
symbols. This meanstext=/^\\s*Login$/i
will match<button> loGIN</button>
with any number of spaces before "Login" and no spaces after.
Note
Malformed selector starting with
"
is automatically transformed to text selector. For example, Playwright convertspage.click('"Login"')
topage.click('text="Login"')
.
id, data-testid, data-test-id, data-test
Id engines are selecting based on the corresponding atrribute value. For example: data-test-id=foo
is equivalent to querySelector('*[data-test-id=foo]')
.
Custom selector engines
Playwright supports custom selector engines, registered with selectors.register(engineFunction[, ...args]).
Selector engine should have the following properties:
name
Selector name used in selector strings.create
Function to create a relative selector fromroot
(root is either aDocument
,ShadowRoot
orElement
) to atarget
element.query
Function to query first element matchingselector
relative to theroot
.queryAll
Function to query all elements matchingselector
relative to theroot
.
An example of registering selector engine that queries elements based on a tag name:
// Must be a function that evaluates to a selector engine instance.
const createTagNameEngine = () => ({
// Selectors will be prefixed with "tag=".
name: 'tag',
// Creates a selector that matches given target when queried at the root.
// Can return undefined if unable to create one.
create(root, target) {
return root.querySelector(target.tagName) === target ? target.tagName : undefined;
},
// Returns the first element matching given selector in the root's subtree.
query(root, selector) {
return root.querySelector(selector);
},
// Returns all elements matching given selector in the root's subtree.
queryAll(root, selector) {
return Array.from(root.querySelectorAll(selector));
}
});
// Register the engine.
await selectors.register(createTagNameEngine);
// Now we can use 'tag=' selectors.
const button = await page.$('tag=button');
// We can combine it with other selector engines.
await page.click('tag=div >> text="Click me"');
// We can use it in any methods supporting selectors.
const buttonCount = await page.$$eval('tag=button', buttons => buttons.length);