@finos/perspective-viewer/dist/docs/classes/PerspectiveViewerPluginElement.md

The `<perspective-viewer>` Custom Element, frontend for Perspective.js

# Class: PerspectiveViewerPluginElement

The `<perspective-viewer-plugin>` element, the default perspective plugin
which is registered and activated automcatically when a
`<perspective-viewer>` is loaded without plugins.  While you will not
typically instantiate this class directly, it is simple enough to function
as a good "default" plugin implementation which can be extended to create
custom plugins.

**`example`**
```javascript
class MyPlugin extends customElements.get("perspective-viewer-plugin") {
   // Custom plugin overrides
}
```

## Hierarchy

- `HTMLElement`

  ↳ **`PerspectiveViewerPluginElement`**

## Implements

- [`IPerspectiveViewerPlugin`](../interfaces/IPerspectiveViewerPlugin.md)

## Table of contents

### Constructors

- [constructor](PerspectiveViewerPluginElement.md#constructor)

### Accessors

- [config\_column\_names](PerspectiveViewerPluginElement.md#config_column_names)
- [min\_config\_columns](PerspectiveViewerPluginElement.md#min_config_columns)
- [name](PerspectiveViewerPluginElement.md#name)
- [select\_mode](PerspectiveViewerPluginElement.md#select_mode)

### Methods

- [clear](PerspectiveViewerPluginElement.md#clear)
- [delete](PerspectiveViewerPluginElement.md#delete)
- [draw](PerspectiveViewerPluginElement.md#draw)
- [resize](PerspectiveViewerPluginElement.md#resize)
- [restore](PerspectiveViewerPluginElement.md#restore)
- [restyle](PerspectiveViewerPluginElement.md#restyle)
- [save](PerspectiveViewerPluginElement.md#save)
- [update](PerspectiveViewerPluginElement.md#update)

## Constructors

### constructor

• **new PerspectiveViewerPluginElement**()

#### Overrides

HTMLElement.constructor

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:182](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L182)

## Accessors

### config\_column\_names

• `get` **config_column_names**(): `string`[]

The named column labels, if desired.  Named columns behave differently
in drag/drop mode than unnamed columns, having replace/swap behavior
rather than insert.  If provided, the length of `config_column_names`
_must_ be `>= min_config_columns`, as this is assumed by the drag/drop
logic.

#### Returns

`string`[]

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:198](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L198)

___

### min\_config\_columns

• `get` **min_config_columns**(): `number`

The minimum number of columns required for this plugin to operate.
This mostly affects drag/drop and column remove button behavior,
preventing the use from applying configs which violate this min.

While this option can technically be `undefined` (as in the case of
`@finos/perspective-viewer-datagrid`), doing so currently has nearly
identical behavior to 1.

#### Returns

`number`

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:194](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L194)

___

### name

• `get` **name**(): `string`

The name for this plugin, which is used as both it's unique key for use
as a parameter for the `plugin` field of a `ViewerConfig`, and as the
display name for this plugin in the `<perspective-viewer>` UI.

#### Returns

`string`

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:186](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L186)

___

### select\_mode

• `get` **select_mode**(): ``"select"`` \| ``"toggle"``

Select mode determines how column add/remove buttons behave for this
plugin.  `"select"` mode exclusively selects the added column, removing
other columns.  `"toggle"` mode toggles the column on or off (dependent
on column state), leaving existing columns alone.

#### Returns

``"select"`` \| ``"toggle"``

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:190](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L190)

## Methods

### clear

▸ **clear**(): `Promise`<`void`\>

Clear this plugin, though it is up to the discretion of the plugin
author to determine what this means.  Defaults to resetting this
element's `innerHTML`, so be sure to override if you want custom
behavior.

#### Returns

`Promise`<`void`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[clear](../interfaces/IPerspectiveViewerPlugin.md#clear)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:213](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L213)

___

### delete

▸ **delete**(): `Promise`<`void`\>

Free any resources acquired by this plugin and prepare to be deleted.

#### Returns

`Promise`<`void`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[delete](../interfaces/IPerspectiveViewerPlugin.md#delete)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:233](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L233)

___

### draw

▸ **draw**(`view`): `Promise`<`void`\>

Render this plugin using the provided `View`.  While there is no
provision to cancel a render in progress per se, calling a method on
a `View` which has been deleted will throw an exception.

#### Parameters

| Name | Type |
| :------ | :------ |
| `view` | `View` |

#### Returns

`Promise`<`void`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[draw](../interfaces/IPerspectiveViewerPlugin.md#draw)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:206](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L206)

___

### resize

▸ **resize**(): `Promise`<`void`\>

Like `update()`, but for when the dimensions of the plugin have changed
and the underlying data has not.

#### Returns

`Promise`<`void`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[resize](../interfaces/IPerspectiveViewerPlugin.md#resize)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:217](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L217)

___

### restore

▸ **restore**(): `Promise`<`void`\>

Restore this plugin to a state previously returned by `save()`.

#### Returns

`Promise`<`void`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[restore](../interfaces/IPerspectiveViewerPlugin.md#restore)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:229](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L229)

___

### restyle

▸ **restyle**(): `Promise`<`void`\>

Notify the plugin that the style environment has changed.  Useful for
plugins which read CSS styles via `window.getComputedStyle()`.

#### Returns

`Promise`<`void`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[restyle](../interfaces/IPerspectiveViewerPlugin.md#restyle)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:221](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L221)

___

### save

▸ **save**(): `Promise`<`any`\>

Save this plugin's state to a JSON-serializable value.  While this value
can be anything, it should work reciprocally with `restore()` to return
this plugin's renderer to the same state, though potentially with a
different `View`.

`save()` should be used for user-persistent settings that are
data-agnostic, so the user can have persistent view during refresh or
reload.  For example, `@finos/perspective-viewer-d3fc` uses
`plugin_config` to remember the user-repositionable legend coordinates.

#### Returns

`Promise`<`any`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[save](../interfaces/IPerspectiveViewerPlugin.md#save)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:225](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L225)

___

### update

▸ **update**(`view`): `Promise`<`void`\>

Draw under the assumption that the `ViewConfig` has not changed since
the previous call to `draw()`, but the underlying data has.  Defaults to
dispatch to `draw()`.

#### Parameters

| Name | Type |
| :------ | :------ |
| `view` | `View` |

#### Returns

`Promise`<`void`\>

#### Implementation of

[IPerspectiveViewerPlugin](../interfaces/IPerspectiveViewerPlugin.md).[update](../interfaces/IPerspectiveViewerPlugin.md#update)

#### Defined in

[rust/perspective-viewer/src/ts/plugin.ts:202](https://github.com/finos/perspective/blob/e19cc4010/rust/perspective-viewer/src/ts/plugin.ts#L202)