# Using Plugins

The Kendo UI for Vue Editor is based on the ProseMirror library. ProseMirror provides a set of tools and concepts for building rich text editors, using user interface inspired by what-you-see-is-what-you-get.

## Concepts

The ProseMirror [plugin system](https://prosemirror.net/docs/ref/#state.Plugin_System) enables developers to create custom tools and functionality. One of the main building blocks of each editor is its [`EditorState`](https://prosemirror.net/docs/ref/#state) object. The state is created through a static [`create`](https://prosemirror.net/docs/ref/#state.EditorState^create) method which takes a configuration object, containing the starting document node, the [schema](https://prosemirror.net/docs/ref/#model.Schema), and a collection of [plugins](https://prosemirror.net/docs/ref/#state.Plugin) which will be active in this state.

Plugins are instances of the [`Plugin` class](https://prosemirror.net/docs/ref/#state.Plugin) and can model a wide variety of features. The basic ones only add some [properties](https://prosemirror.net/docs/ref/#view.EditorProps) to the editor view to respond to certain events, for example. More complicated features may add a new state to the editor and update it based on [transactions](https://prosemirror.net/docs/ref/#state.Transaction).

For further details about the ProseMirror plugins, refer to the [this ProseMirror guide](https://prosemirror.net/docs/guide/#state.plugins).



## Placeholders

You can use a plugin to provide a placeholder functionality for the Editor which is similar to the [placeholder](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input#The_placeholder_attribute) attribute of the HTML `input` element.

[Demo Source](https://demos.telerik.com/kendo-vue-ui/editor/plugins/placeholder/source.txt)

## Read Only

A Read-Only functionality can be implemented using a plugin as well.

The following example demonstrates how to implement a plugin which provides Read-Only functionality.

[Demo Source](https://demos.telerik.com/kendo-vue-ui/editor/plugins/readonly/source.txt)



## Suggested Links

* [API Reference of the Editor](https://www.telerik.com/kendo-vue-ui-develop/components/editor/api/editor)
* [ProseMirror Plugin System](http://prosemirror.net/docs/ref/#state.Plugin_System)