element-plus/docs/en-US/component/image.md
msidolphin 2ed6fc4cee
docs: [el-image] add preview-append-to-body (#5901)
* docs: [el-image] add preview-append-to-body

* chore: rename
2022-02-11 11:41:29 +08:00

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---
title: Image
lang: en-US
---
# Image
Besides the native features of img, support lazy load, custom placeholder and load failure, etc.
## Basic Usage
:::demo Indicate how the image should be resized to fit its container by `fit`, same as native [object-fit](https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit)。
image/basic-usage
:::
## Placeholder
:::demo Custom placeholder content when image hasn't loaded yet by `slot = placeholder`
image/placeholder
:::
## Load Failed
:::demo Custom failed content when error occurs to image load by `slot = error`
image/load-failed
:::
## Lazy Load
:::demo Use lazy load by `lazy = true`. Image will load until scroll into view when set. You can indicate scroll container that adds scroll listener to by `scroll-container`. If undefined, will be the nearest parent container whose overflow property is auto or scroll.
image/lazy-load
:::
## Image Preview
:::demo allow big image preview by setting `previewSrcList` prop. You can initialize the position of the first picture previewed by `initial-index`. The default initial position is 0.
image/image-preview
:::
## Image Attributes
| Attribute | Description | Type | Accepted values | Default |
| ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ | -------------------- | ------------------------------------------ | ---------------------------------------------------------------------- |
| alt | Native alt | string | - | - |
| fit | Indicate how the image should be resized to fit its container, same as [object-fit](https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit) | string | fill / contain / cover / none / scale-down | - |
| hide-on-click-modal | When enabling preview, use this flag to control whether clicking on backdrop can exit preview mode | boolean | true / false | false |
| initial-index | The initial preview image index, less than the length of `url-list` | number | int | 0 |
| lazy | Whether to use lazy load | boolean | — | false |
| preview-src-list | allow big image preview | Array | — | - |
| referrer-policy | Native referrerPolicy | string | - | - |
| src | Image source, same as native | string | — | - |
| scroll-container | The container to add scroll listener when using lazy load | string / HTMLElement | — | The nearest parent container whose overflow property is auto or scroll |
| z-index | set image preview z-index | Number | — | 2000 |
| preview-teleported | whether to append image-viewer to body. A nested parent element attribute transform should have this attribute set to `true` | boolean | — | false |
## Image Events
| Event Name | Description | Parameters |
| ---------- | -------------------- | ---------- |
| load | Same as native load | (e: Event) |
| error | Same as native error | (e: Error) |
## Image Slots
| Name | Description |
| ----------- | ------------------------------- |
| placeholder | Triggers when image load |
| error | Triggers when image load failed |
## ImageViewer Attributes
| Attribute | Description | Type | Acceptable Value | Default |
| ------------------- | ---------------------------------------------------------------------------------------------------------------------------- | --------------- | ------------------- | ------- |
| url-list | Preview link list | Array\<string\> | - | [] |
| z-index | Preview backdrop z-index | number / string | int / string\<int\> | 2000 |
| initial-index | The initial preview image index, less than or equal to the length of `url-list` | number | int | 0 |
| infinite | Whether preview is infinite | boolean | true / false | true |
| hide-on-click-modal | Whether user can emit close event when clicking backdrop | boolean | true / false | false |
| teleported | whether to append image itself to body. A nested parent element attribute transform should have this attribute set to `true` | boolean | — | false |
## ImageViewer Events
| Event name | Description | Callback parameter |
| ---------- | ---------------------------------------------------------------------------------------------- | -------------------------------------- |
| close | Emitted when clicking on `X` button or when `hide-on-click-modal` enabled clicking on backdrop | None |
| switch | When switching images | `(val: number)` switching target index |