puppeteer/docs/guides/page-interactions.md
2024-04-11 11:08:28 +02:00

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# Page interactions
Puppeteer allows you interact with the pages in various ways.
## Locators
Locators is a new, experimental API that combines the functionalities of
waiting and actions. With additional precondition checks, it
enables automatic retries for failed actions, resulting in more reliable and
less flaky automation scripts.
:::note
Locators API is experimental and we will not follow semver for breaking changes
in the Locators API.
:::
### Use cases
#### Waiting for an element
```ts
await page.locator('button').wait();
```
The following preconditions are automatically checked:
- Waits for the element to become
[visible](https://pptr.dev/api/puppeteer.elementhandle.isvisible/) or hidden.
#### Waiting for a function
```ts
await page
.locator(() => {
let resolve!: (node: HTMLCanvasElement) => void;
const promise = new Promise(res => {
return (resolve = res);
});
const observer = new MutationObserver(records => {
for (const record of records) {
if (record.target instanceof HTMLCanvasElement) {
resolve(record.target);
}
}
});
observer.observe(document);
return promise;
})
.wait();
```
#### Clicking an element
```ts
await page.locator('button').click();
```
The following preconditions are automatically checked:
- Ensures the element is in the viewport.
- Waits for the element to become
[visible](https://pptr.dev/api/puppeteer.elementhandle.isvisible/) or hidden.
- Waits for the element to become enabled.
- Waits for the element to have a stable bounding box over two consecutive
animation frames.
#### Clicking an element matching a criteria
```ts
await page
.locator('button')
.filter(button => !button.disabled)
.click();
```
The following preconditions are automatically checked:
- Ensures the element is in the viewport.
- Waits for the element to become
[visible](https://pptr.dev/api/puppeteer.elementhandle.isvisible/) or hidden.
- Waits for the element to become enabled.
- Waits for the element to have a stable bounding box over two consecutive
animation frames.
#### Filling out an input
```ts
await page.locator('input').fill('value');
```
Automatically detects the input type and choose an appropriate way to fill it out with the provided value.
The following preconditions are automatically checked:
- Ensures the element is in the viewport.
- Waits for the element to become
[visible](https://pptr.dev/api/puppeteer.elementhandle.isvisible/) or hidden.
- Waits for the element to become enabled.
- Waits for the element to have a stable bounding box over two consecutive
animation frames.
#### Retrieving an element property
```ts
const enabled = await page
.locator('button')
.map(button => !button.disabled)
.wait();
```
#### Hover over an element
```ts
await page.locator('div').hover();
```
The following preconditions are automatically checked:
- Ensures the element is in the viewport.
- Waits for the element to become
[visible](https://pptr.dev/api/puppeteer.elementhandle.isvisible/) or hidden.
- Waits for the element to have a stable bounding box over two consecutive
animation frames.
#### Scroll an element
```ts
await page.locator('div').scroll({
scrollLeft: 10,
scrollTop: 20,
});
```
The following preconditions are automatically checked:
- Ensures the element is in the viewport.
- Waits for the element to become
[visible](https://pptr.dev/api/puppeteer.elementhandle.isvisible/) or hidden.
- Waits for the element to have a stable bounding box over two consecutive
animation frames.
### Configuring locators
Locators can be configured to tune configure the preconditions and other other options:
```ts
await page
.locator('button')
.setEnsureElementIsInTheViewport(false)
.setTimeout(0)
.setVisibility(null)
.setWaitForEnabled(false)
.setWaitForStableBoundingBox(false)
.click();
```
### Getting locator events
Currently, locators support a single event that notifies you when the locator is about to perform the action:
```ts
let willClick = false;
await page
.locator('button')
.on(LocatorEvent.Action, () => {
willClick = true;
})
.click();
```
This event can be used for logging/debugging or other purposes. The event might
fire multiple times if the locator retries the action.
## Query Selectors
Queries are the primary mechanism for interacting with the DOM on your site. For example, a typical workflow goes like:
```ts
// Import puppeteer
import puppeteer from 'puppeteer';
(async () => {
// Launch the browser
const browser = await puppeteer.launch();
// Create a page
const page = await browser.newPage();
// Go to your site
await page.goto('YOUR_SITE');
// Query for an element handle.
const element = await page.waitForSelector('div > .class-name');
// Do something with element...
await element.click(); // Just an example.
// Dispose of handle
await element.dispose();
// Close browser.
await browser.close();
})();
```
### `P` Selectors
Puppeteer uses a superset of the CSS selector syntax for querying. We call this syntax _P selectors_ and it's supercharged with extra capabilities such as deep combinators and text selection.
:::caution
Although P selectors look like real CSS selectors (we intentionally designed it this way), they should not be used for actually CSS styling. They are designed only for Puppeteer.
:::
:::note
P selectors only work on the first "depth" of selectors; for example, `:is(div >>> a)` will not work.
:::
#### `>>>` and `>>>>` combinators
The `>>>` and `>>>>` are called _deep descendent_ and _deep_ combinators respectively. Both combinators have the effect of going into shadow hosts with `>>>` going into every shadow host under a node and `>>>>` going into the immediate one (if the node is a shadow host; otherwise, it's a no-op).
:::note
A common question is when should `>>>>` be chosen over `>>>` considering the flexibility of `>>>`. A similar question can be asked about `>` and a space; choose `>` if you do not need to query all elements under a given node and a space otherwise. This answer extends to `>>>>` (`>`) and `>>>` (space) naturally.
:::
##### Example
Suppose we have the markup
```html
<custom-element>
<template shadowrootmode="open">
<slot></slot>
</template>
<custom-element>
<template shadowrootmode="open">
<slot></slot>
</template>
<custom-element>
<template shadowrootmode="open">
<slot></slot>
</template>
<h2>Light content</h2>
</custom-element>
</custom-element>
</custom-element>
```
> Note: `<template shadowrootmode="open">` is not supported on Firefox.
> You can read more about it [here](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/template#attributes).
Then `custom-element >>> h2` will return `h2`, but `custom-element >>>> h2` will return nothing since the inner `h2` is in a deeper shadow root.
#### `P`-elements
`P` elements are [pseudo-elements](https://developer.mozilla.org/en-US/docs/Web/CSS/Pseudo-elements) with a `-p` vendor prefix. It allows you to enhance your selectors with Puppeteer-specific query engines such as XPath, text queries, and ARIA.
##### Text selectors (`-p-text`)
Text selectors will select "minimal" elements containing the given text, even within (open) shadow roots. Here, "minimum" means the deepest elements that contain a given text, but not their parents (which technically will also contain the given text).
###### Example
```ts
const element = await page.waitForSelector('div ::-p-text(My name is Jun)');
// You can also use escapes.
const element = await page.waitForSelector(
':scope >>> ::-p-text(My name is Jun \\(pronounced like "June"\\))'
);
// or quotes
const element = await page.waitForSelector(
'div >>>> ::-p-text("My name is Jun (pronounced like \\"June\\")"):hover'
);
```
##### XPath selectors (`-p-xpath`)
XPath selectors will use the browser's native [`Document.evaluate`](https://developer.mozilla.org/en-US/docs/Web/API/Document/evaluate) to query for elements.
###### Example
```ts
const element = await page.waitForSelector('::-p-xpath(h2)');
```
##### ARIA selectors (`-p-aria`)
ARIA selectors can be used to find elements with a given ARIA label. These labels are computed using Chrome's internal representation.
###### Example
```ts
const node = await page.waitForSelector('::-p-aria(Submit)');
const node = await page.waitForSelector(
'::-p-aria([name="Click me"][role="button"])'
);
```
#### Custom selectors
Puppeteer provides users the ability to add their own query selectors to Puppeteer using [Puppeteer.registerCustomQueryHandler](../api/puppeteer.registercustomqueryhandler.md). This is useful for creating custom selectors based on framework objects or other vendor-specific objects.
##### Custom Selectors
You can register a custom query handler that allows you to create custom selectors. For example, define a query handler for `getById` selectors:
```ts
Puppeteer.registerCustomQueryHandler('getById', {
queryOne: (elementOrDocument, selector) => {
return elementOrDocument.querySelector(`[id="${CSS.escape(selector)}"]`);
},
// Note: for demonstation perpose only `id` should be page unique
queryAll: (elementOrDocument, selector) => {
return elementOrDocument.querySelectorAll(`[id="${CSS.escape(selector)}"]`);
},
});
```
You can now use it as following:
```ts
const node = await page.waitForSelector('::-p-getById(elementId)');
// OR used in conjunction with other selectors
const moreSpecificNode = await page.waitForSelector(
'.side-bar ::-p-getById(elementId)'
);
```
##### Custom framework components selector
:::caution
Be careful when relying on internal APIs of libraries or frameworks. They can change at any time.
:::
Find Vue components by name by using Vue internals for querying:
```ts
Puppeteer.registerCustomQueryHandler('vue', {
queryOne: (element, name) => {
const walker = document.createTreeWalker(element, NodeFilter.SHOW_ELEMENT);
do {
const currentNode = walker.currentNode;
if (
currentNode.__vnode?.ctx?.type?.name.toLowerCase() ===
name.toLocaleLowerCase()
) {
return currentNode;
}
} while (walker.nextNode());
return null;
},
});
```
Query the Vue component as following:
```ts
const element = await page.$('::-p-vue(MyComponent)');
```
##### Web Components
Web Components create their own tag so you can query them by the tag name:
```ts
const element = await page.$('my-web-component');
```
Extend `HTMLElementTagNameMap` to define types for custom tags. This allows Puppeteer to infer the return type for the ElementHandle:
```ts
declare global {
interface HTMLElementTagNameMap {
'my-web-component': MyWebComponent;
}
}
```
## Query Selectors (legacy)
:::caution
While we maintin prefixed selectors, the recommended way is to use the selector syntax documented above.
:::
Queries are the primary mechanism for interacting with the DOM on your site. For example, a typical workflow goes like:
```ts
// Import puppeteer
import puppeteer from 'puppeteer';
(async () => {
// Launch the browser
const browser = await puppeteer.launch();
// Create a page
const page = await browser.newPage();
// Go to your site
await page.goto('YOUR_SITE');
// Query for an element handle.
const element = await page.waitForSelector('div > .class-name');
// Do something with element...
await element.click(); // Just an example.
// Dispose of handle
await element.dispose();
// Close browser.
await browser.close();
})();
```
### CSS
CSS selectors follow the CSS spec of the browser being automated. We provide some basic type deduction for CSS selectors (such as `HTMLInputElement` for `input`), but any selector that contains no type information (such as `.class-name`) will need to be coerced manually using TypeScript's `as` coercion mechanism.
#### Example
```ts
// Automatic
const element = await page.waitForSelector('div > input');
// Manual
const element = (await page.waitForSelector(
'div > .class-name-for-input'
)) as HTMLInputElement;
```
### Built-in selectors
Built-in selectors are Puppeteer's own class of selectors for doing things CSS cannot. Every built-in selector starts with a prefix `.../` to assist Puppeteer in distinguishing between CSS selectors and a built-in.
#### Text selectors (`text/`)
Text selectors will select "minimal" elements containing the given text, even within (open) shadow roots. Here, "minimum" means the deepest elements that contain a given text, but not their parents (which technically will also contain the given text).
##### Example
```ts
// Note we usually need type coercion since the type cannot be deduced, but for text selectors, `instanceof` checks may be better for runtime validation.
const element = await page.waitForSelector('text/My name is Jun');
```
#### XPath selectors (`xpath/`)
XPath selectors will use the browser's native [`Document.evaluate`](https://developer.mozilla.org/en-US/docs/Web/API/Document/evaluate) to query for elements.
##### Example
```ts
// There is not type deduction for XPaths.
const node = await page.waitForSelector('xpath/h2');
```
#### ARIA selectors (`aria/`)
ARIA selectors can be used to find elements with a given ARIA label. These labels are computed using Chrome's internal representation.
##### Example
```ts
const node = await page.waitForSelector('aria/Button name');
```
#### Pierce selectors (`pierce/`)
Pierce selectors will run the `querySelector*` API on the document and all shadow roots to find an element.
:::danger
Selectors will **not** _partially_ pierce through shadow roots. See the examples below.
:::
##### Example
Suppose the HTML is
```html
<div>
<custom-element>
<div></div>
</custom-element>
</div>
```
Then
```ts
// This will be two elements because of the outer and inner div.
expect((await page.$$('pierce/div')).length).toBe(2);
// Partial piercing doesn't work.
expect((await page.$$('pierce/div div')).length).toBe(0);
```
### Custom selectors
Puppeteer provides users the ability to add their own query selectors to Puppeteer using [Puppeteer.registerCustomQueryHandler](../api/puppeteer.registercustomqueryhandler.md). This is useful for creating custom selectors based on framework objects or other vendor-specific objects.