## Upload
Upload files by clicking or drag-and-drop
### Click to upload files
:::demo Customize upload button type and text using `slot`. Set `limit` and `on-exceed` to limit the maximum number of uploads allowed and specify method when the limit is exceeded. Plus, you can abort removing a file in the `before-remove` hook.
```html
Click to upload
jpg/png files with a size less than 500kb
```
:::
### User avatar upload
Use `before-upload` hook to limit the upload file format and size.
:::demo
```html
```
:::
### Photo Wall
Use `list-type` to change the fileList style.
:::demo
```html
```
:::
### Custom file thumbnail
Use `scoped-slot` to change default thumbnail template.
:::demo
```html
```
:::
### FileList with thumbnail
:::demo
```html
Click to upload
jpg/png files with a size less than 500kb
```
:::
### File list control
Use `on-change` hook function to control upload file list
:::demo
```html
Click to upload
jpg/png files with a size less than 500kb
```
:::
### Drag to upload
You can drag your file to a certain area to upload it.
:::demo
```html
Drop file here or click to upload
jpg/png files with a size less than 500kb
```
:::
### Manual upload
:::demo
```html
select fileupload to server
jpg/png files with a size less than 500kb
```
:::
### Attributes
| Attribute | Description | Type | Accepted Values | Default |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------- | ------------------------- | ------- |
| action | required, request URL | string | — | — |
| headers | request headers | object | — | — |
| method | set upload request method | string | post/put | post |
| multiple | whether uploading multiple files is permitted | boolean | — | — |
| data | additions options of request | object | — | — |
| name | key name for uploaded file | string | — | file |
| with-credentials | whether cookies are sent | boolean | — | false |
| show-file-list | whether to show the uploaded file list | boolean | — | true |
| drag | whether to activate drag and drop mode | boolean | — | false |
| accept | accepted [file types](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input#attr-accept), will not work when `thumbnail-mode` is `true` | string | — | — |
| on-preview | hook function when clicking the uploaded files | function(file) | — | — |
| on-remove | hook function when files are removed | function(file, fileList) | — | — |
| on-success | hook function when uploaded successfully | function(response, file, fileList) | — | — |
| on-error | hook function when some errors occurs | function(err, file, fileList) | — | — |
| on-progress | hook function when some progress occurs | function(event, file, fileList) | — | — |
| on-change | hook function when select file or upload file success or upload file fail | function(file, fileList) | — | — |
| before-upload | hook function before uploading with the file to be uploaded as its parameter. If `false` is returned or a `Promise` is returned and then is rejected, uploading will be aborted | function(file) | — | — |
| before-remove | hook function before removing a file with the file and file list as its parameters. If `false` is returned or a `Promise` is returned and then is rejected, removing will be aborted. | function(file, fileList) | — | — |
| thumbnail-mode | whether thumbnail is displayed | boolean | — | false |
| file-list | default uploaded files, e.g. [{name: 'food.jpg', url: 'https://xxx.cdn.com/xxx.jpg'}] | array | — | [] |
| list-type | type of fileList | string | text/picture/picture-card | text |
| auto-upload | whether to auto upload file | boolean | — | true |
| http-request | override default xhr behavior, allowing you to implement your own upload-file's request | function | — | — |
| disabled | whether to disable upload | boolean | — | false |
| limit | maximum number of uploads allowed | number | — | — |
| on-exceed | hook function when limit is exceeded | function(files, fileList) | — | - |
### Slots
| Name | Description |
| ------- | ---------------------------------- |
| trigger | content which triggers file dialog |
| tip | content of tips |
### Methods
| Methods Name | Description | Parameters |
| ------------ | --------------------------------------------------------------------------------------- | --------------------------- |
| clearFiles | clear the uploaded file list (this method is not supported in the `before-upload` hook) | — |
| abort | cancel upload request | ( file: fileList's item ) |
| submit | upload the file list manually | — |