category: framework-tutorials
In this tutorial, you will learn how to implement a more complex CKEditor 5 plugin. We will build a "Simple box" feature which will allow the user to insert a custom box with a title and body fields into the document. We will use the widget utils and work with the model-view conversion in order to properly set up the behavior of this feature. Later on, we will create a UI which will allow inserting new simple boxes into the document via the toolbar button.
If you want to see the final product of this tutorial before you plunge in, check out the [demo](#demo).
While it is not strictly necessary to read the {@link framework/guides/quick-start Quick start} guide before going through this tutorial, it may help you to get more comfortable with CKEditor 5 framework before you will dive into this tutorial.
We will also reference various parts of the {@link framework/guides/architecture/intro CKEditor 5 architecture} section as we go. While reading them is not necessary to finish this tutorial, we recommend reading those guides at some point to get a better understanding of the mechanisms used in this tutorial.
This guide assumes that you are familiar with npm and your project uses npm already. If not, see the npm documentation or call npm init in an empty directory and keep your fingers crossed.
First, install packages needed to build and set up a basic CKEditor 5 instance.
npm install --save \
postcss-loader \
raw-loader \
style-loader \
webpack@4 \
webpack-cli@3 \
@ckeditor/ckeditor5-dev-utils \
@ckeditor/ckeditor5-editor-classic \
@ckeditor/ckeditor5-essentials \
@ckeditor/ckeditor5-paragraph \
@ckeditor/ckeditor5-heading \
@ckeditor/ckeditor5-list \
@ckeditor/ckeditor5-basic-styles \
@ckeditor/ckeditor5-theme-lark
Create minimal webpack configuration:
// webpack.config.js
'use strict';
const path = require( 'path' );
const { styles } = require( '@ckeditor/ckeditor5-dev-utils' );
module.exports = {
entry: './app.js',
output: {
path: path.resolve( __dirname, 'dist' ),
filename: 'bundle.js'
},
module: {
rules: [
{
test: /\.svg$/,
use: [ 'raw-loader' ]
},
{
test: /\.css$/,
use: [
{
loader: 'style-loader',
options: {
singleton: true
}
},
{
loader: 'postcss-loader',
options: styles.getPostCssConfig( {
themeImporter: {
themePath: require.resolve( '@ckeditor/ckeditor5-theme-lark' )
},
minify: true
} )
},
]
}
]
},
// Useful for debugging.
devtool: 'source-map',
// By default webpack logs warnings if the bundle is bigger than 200kb.
performance: { hints: false }
};
Create your project's entry point:
// app.js
import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials';
import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph';
import Heading from '@ckeditor/ckeditor5-heading/src/heading';
import List from '@ckeditor/ckeditor5-list/src/list';
import Bold from '@ckeditor/ckeditor5-basic-styles/src/bold';
import Italic from '@ckeditor/ckeditor5-basic-styles/src/italic';
ClassicEditor
.create( document.querySelector( '#editor' ), {
plugins: [ Essentials, Paragraph, Heading, List, Bold, Italic ],
toolbar: [ 'heading', 'bold', 'italic', 'numberedList', 'bulletedList' ]
} )
.then( editor => {
console.log( 'Editor was initialized', editor );
// Expose for playing in the console.
window.editor = editor;
} )
.catch( error => {
console.error( error.stack );
} );
And an index.html page:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>CKEditor 5 Framework – Implementing a simple widget</title>
</head>
<body>
<div id="editor">
<p>Editor content goes here.</p>
</div>
<script src="dist/bundle.js"></script>
</body>
</html>
Finally, let's build your project and see if everything worked well by opening the index page in your browser:
p@m /workspace/creating-a-plugin> ./node_modules/.bin/webpack --mode development
Hash: a4a7cf092b8d69199848
Version: webpack 4.28.4
Time: 5467ms
Built at: 2019-01-15 10:49:01
Asset Size Chunks Chunk Names
bundle.js 3.52 MiB main [emitted] [big] main
bundle.js.map 3.2 MiB main [emitted] main
Entrypoint main [big] = bundle.js bundle.js.map
[./app.js] 824 bytes {main} [built]
[./node_modules/webpack/buildin/global.js] (webpack)/buildin/global.js 472 bytes {main} [built]
[./node_modules/webpack/buildin/harmony-module.js] (webpack)/buildin/harmony-module.js 573 bytes {main} [built]
+ 904 hidden modules
You should see a CKEditor 5 instance like this:
{@img assets/img/tutorial-implementing-a-widget-1.png Screenshot of a classic editor initialized from source.}
Once the editor is up and running we can start implementing the plugin. All the code of a plugin can be kept in a single file, however, we recommend splitting its "editing" and "UI" layers and creating a master plugin which loads both. This way, we ensure better separation of concerns and allow recomposing the features (e.g. picking the editing part of an existing feature but writing your own UI for it). All official CKEditor 5 plugins follow this pattern.
Additionally, we will split code of commands, buttons and other "self-contained" components to separate files as well. In order to not mix up these files with your project's app.js and webpack.config.js files, let's create this directory structure:
├── app.js
├── dist
│ ├── bundle.js
│ └── bundle.js.map
├── index.html
├── node_modules
├── package.json
├── simplebox
│ ├── simplebox.js
│ ├── simpleboxediting.js
│ └── simpleboxui.js
│
│ ... the rest of plugin files go here as well
│
└── webpack.config.js
Let's now define the 3 plugins.
First, the master (glue) plugin. Its role is to simply load the "editing" and "UI" parts.
// simplebox/simplebox.js
import SimpleBoxEditing from './simpleboxediting';
import SimpleBoxUI from './simpleboxui';
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
export default class SimpleBox extends Plugin {
static get requires() {
return [ SimpleBoxEditing, SimpleBoxUI ];
}
}
Now, the remaining two plugins:
// simplebox/simpleboxui.js
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
export default class SimpleBoxUI extends Plugin {
init() {
console.log( 'SimpleBoxUI#init() got called' );
}
}
// simplebox/simpleboxediting.js
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
export default class SimpleBoxEditing extends Plugin {
init() {
console.log( 'SimpleBoxEditing#init() got called' );
}
}
Finally, we need to load the SimpleBox plugin in our app.js file:
// app.js
import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials';
import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph';
import Heading from '@ckeditor/ckeditor5-heading/src/heading';
import List from '@ckeditor/ckeditor5-list/src/list';
import Bold from '@ckeditor/ckeditor5-basic-styles/src/bold';
import Italic from '@ckeditor/ckeditor5-basic-styles/src/italic';
import SimpleBox from './simplebox/simplebox'; // ADDED
ClassicEditor
.create( document.querySelector( '#editor' ), {
plugins: [
Essentials, Paragraph, Heading, List, Bold, Italic,
SimpleBox // ADDED
],
toolbar: [ 'heading', 'bold', 'italic', 'numberedList', 'bulletedList' ]
} )
.then( editor => {
console.log( 'Editor was initialized', editor );
// Expose for playing in the console.
window.editor = editor;
} )
.catch( error => {
console.error( error.stack );
} );
Rebuild your project, refresh the browser and you should see that the SimpleBoxEditing and SmpleBoxUI plugins were loaded:
{@img assets/img/tutorial-implementing-a-widget-2.png Screenshot of a classic editor initialized from source with the SimpleBoxEditing#init() got called and SimpleBoxUI#init() got called messages on the console.}
CKEditor 5 implements an MVC architecture and its custom data model, while still being a tree structure, does not map to the DOM 1:1. You can think about the model as about an even more semantical representation of the editor content, while the DOM is one of its possible representations.
Read more about the {@link framework/guides/architecture/editing-engine#overview editing engine architecture}.
Since our simple box feature is meant to be a box with a title and description fields, let's define its model representation like this:
<simpleBox>
<simpleBoxTitle></simpleBoxTitle>
<simpleBoxDescription></simpleBoxDescription>
</simpleBox>
We need to start with defining the model's schema. We need to define there 3 elements and their types and allowed parent/children.
Read more about the {@link framework/guides/architecture/editing-engine#schema schema}.
Let's update the SimpleBoxEditing plugin with this definition.
// simplebox/simpleboxediting.js
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
export default class SimpleBoxEditing extends Plugin {
init() {
console.log( 'SimpleBoxEditing#init() got called' );
this._defineSchema(); // ADDED
}
_defineSchema() { // ADDED
const schema = this.editor.model.schema;
schema.register( 'simpleBox', {
// Behaves like a self-contained object (e.g. an image).
isObject: true,
// Allow in places where other blocks are allowed (e.g. directly in the root).
allowWhere: '$block'
} );
schema.register( 'simpleBoxTitle', {
// Cannot be split or left by the caret.
isLimit: true,
allowIn: 'simpleBox',
// Allow content which is allowed in blocks (i.e. text with attributes).
allowContentOf: '$block'
} );
schema.register( 'simpleBoxDescription', {
// Cannot be split or left by the caret.
isLimit: true,
allowIn: 'simpleBox',
// Allow content which is allowed in the root (e.g. paragraphs).
allowContentOf: '$root'
} );
}
}
Defining the schema will not have any effect on the editor just yet. It is information which can be used by plugins and the editor engine to understand how actions like pressing the Enter key, clicking on an element, typing text, inserting an image, etc. should behave.
For the simple box plugin to start doing anything we need to define model-view converters. Let's do that!
Converters tell the editor how to convert the view to the model (e.g. when loading the data to the editor or handling pasted content) and how to render the model to the view (for editing purposes, or when retrieving editor data).
Read more about the {@link framework/guides/architecture/editing-engine#conversion model-view conversion}.
This is the moment when we need to think about how we want to render the <simpleBox> element and its children to the DOM (what user will see) and to the data. CKEditor 5 allows converting the model to a different structure for editing purposes and a different one to be stored as "data" or exchanged with other applications when copy-pasting the content. However, for simplicity, let's use the same representation in both pipelines for now.
The structure in the view that we want to achieve:
<section class="simple-box">
<h1 class="simple-box-title"></h1>
<div class="simple-box-description"></div>
</section>
Let's use the {@link module:engine/conversion/conversion~Conversion#elementToElement conversion.elementToElement()} method to define all the converters.
We can use this high-level two-way converters definition because we define the same converters for the {@link framework/guides/architecture/editing-engine#data-pipeline data} and {@link framework/guides/architecture/editing-engine#editing-pipeline editing} pipelines.
Later on we will switch to more fine-grained converters to get more control over the conversion.
We need to define converters for 3 model elements. Let's update the SimpleBoxEditing plugin with this code:
// simplebox/simpleboxediting.js
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
export default class SimpleBoxEditing extends Plugin {
init() {
console.log( 'SimpleBoxEditing#init() got called' );
this._defineSchema();
this._defineConverters(); // ADDED
}
_defineSchema() {
// ...
}
_defineConverters() { // ADDED
const conversion = this.editor.conversion;
conversion.elementToElement( {
model: 'simpleBox',
view: {
name: 'section',
classes: 'simple-box'
}
} );
conversion.elementToElement( {
model: 'simpleBoxTitle',
view: {
name: 'h1',
classes: 'simple-box-title'
}
} );
conversion.elementToElement( {
model: 'simpleBoxDescription',
view: {
name: 'div',
classes: 'simple-box-description'
}
} );
}
}
Once we have converters, we can try to see the simple box in action. We did not define yet a way to insert a new simple box into the document, so let's load it via the editor data. In order to do that, we need to modify the index.html file:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>CKEditor 5 Framework – Implementing a simple widget</title>
<style>
.simple-box {
padding: 10px;
margin: 1em 0;
background: rgba( 0, 0, 0, 0.1 );
border: solid 1px hsl(0, 0%, 77%);
border-radius: 2px;
}
.simple-box-title, .simple-box-description {
padding: 10px;
margin: 0;
background: #FFF;
border: solid 1px hsl(0, 0%, 77%);
}
.simple-box-title {
margin-bottom: 10px;
}
</style>
</head>
<body>
<div id="editor">
<p>This is a simple box:</p>
<section class="simple-box">
<h1 class="simple-box-title">Box title</h1>
<div class="simple-box-description">
<p>The description goes here.</p>
<ul>
<li>It can contain lists,</li>
<li>and other block elements like headings.</li>
</ul>
</div>
</section>
</div>
<script src="dist/bundle.js"></script>
</body>
</html>
Rebuild your project and voila — that's your first simple box instance:
{@img assets/img/tutorial-implementing-a-widget-3.png Screenshot of a classic editor with an instance of a simple box inside.}
The HTML that you have added to the index.html file is your editor's data. This is what editor.getData() would return. Also, for now, this also the DOM structure which is rendered by CKEditor 5's engine in the editable region:
{@img assets/img/tutorial-implementing-a-widget-4.png Screenshot of a DOM structure of the simple box instance – it looks exactly like the data loaded into the editor.}
However, what's in the model?
To learn that, we recommend using the official {@link framework/guides/development-tools#ckeditor-5-inspector CKEditor 5 inspector}. Once {@link framework/guides/development-tools#ckeditor-5-inspector#installing-the-inspector installed}, you need to load it in the app.js file:
// app.js
import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials';
import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph';
import Heading from '@ckeditor/ckeditor5-heading/src/heading';
import List from '@ckeditor/ckeditor5-list/src/list';
import Bold from '@ckeditor/ckeditor5-basic-styles/src/bold';
import Italic from '@ckeditor/ckeditor5-basic-styles/src/italic';
import SimpleBox from './simplebox/simplebox';
import CKEditorInspector from '@ckeditor/ckeditor5-inspector'; // ADDED
ClassicEditor
.create( document.querySelector( '#editor' ), {
plugins: [
Essentials, Paragraph, Heading, List, Bold, Italic,
SimpleBox
],
toolbar: [ 'heading', 'bold', 'italic', 'numberedList', 'bulletedList' ]
} )
.then( editor => {
console.log( 'Editor was initialized', editor );
CKEditorInspector.attach( 'editor', editor );
window.editor = editor;
} )
.catch( error => {
console.error( error.stack );
} );
After rebuilding your project and refreshing the page you will see the inspector:
{@img assets/img/tutorial-implementing-a-widget-4b.png Screenshot of a the simple box widget's structure displayed by CKEditor 5 inspector.}
You will see the following HTML-like string:
<paragraph>[]This is a simple box:</paragraph>
<simpleBox>
<simpleBoxTitle>Box title</simpleBoxTitle>
<simpleBoxDescription>
<paragraph>The description goes here.</paragraph>
<listItem listIndent="0" listType="bulleted">It can contain lists,</listItem>
<listItem listIndent="0" listType="bulleted">and other block elements like headings.</listItem>
</simpleBoxDescription>
</simpleBox>
As you can see, this structure is quite different than the HTML input/output. If you look closely, you will also notice the [] characters in the first paragraph — that's selection position.
Play a bit with editor features (bold, italic, headings, lists, selection) to see how the model structure changes.
You can also use some {@link framework/guides/development-tools#testing-helpers useful helpers like `getData()` and `setData()`} to learn more about the state of the editor model or write assertions in tests.
It is time to check if the simple box behaves like we would like it to. You can observe the following:
isLimit element in the schema.<h1 class="simple-box-title"> which it is already). That is because it allows only the content that is allowed in other block elements (like paragraphs). You can, however, apply italic inside a title (because italic is allowed in other blocks).isObject element in the schema.Pretty cool so far, right? With a very little code, you were able to define a behavior of your simple box plugin which maintains the integrity of those elements. The engine ensures that the user does not break those instances.
Let's see what else we can improve.
If you are familiar with the {@link @ckeditor4 guide/dev_widgets Widget System of CKEditor 4} you will notice significant differences in how widgets are implemented in CKEditor 5.
CKEditor 4's implementation exposes a declarative API which controls the entire behavior of a widget (from its schema and internal model to the styles, clicking behavior, context menu and the dialog).
In CKEditor 5 the widget system was redesigned. Most of its responsibilities were taken over by the engine, some were extracted to a separate package ({@link api/widget `@ckeditor/ckeditor5-widget`}) and some have to be handled by other utils provided by CKEditor 5 framework.
CKEditor 5's implementation is, therefore, open for extensions and recomposition. You can choose those behaviors that you want (just like we did so far in this tutorial by defining a schema) and skip others or implement them by yourself.
The converters that we defined convert the model <simpleBox*> elements to plain {@link module:engine/view/containerelement~ContainerElement ContainerElement}s in the view (and back during upcasting).
We want to change this behavior a bit so the structure created in the editing view is enhanced with the {@link module:widget/utils~toWidget toWidget()} and {@link module:widget/utils~toWidgetEditable toWidgetEditable()} utils. We do not want to affect the data view, though. Therefore, we will need to define converters for the editing and data downcasting separately.
If you find the concept of downcasting and upcasting confusing, read the {@link framework/guides/architecture/editing-engine#conversion introduction to conversion}.
Before we start coding, we need to install the {@link api/widget @ckeditor/ckeditor5-widget} package:
npm install --save @ckeditor/ckeditor5-widget
Now, let's revisit the _defineConverters() method that we defined earlier. We will use {@link module:engine/conversion/upcasthelpers~UpcastHelpers#elementToElement elementToElement() upcast helper} and {@link module:engine/conversion/downcasthelpers~DowncastHelpers#elementToElement elementToElement() downcast helper} instead of the two-way elementToElement() converter helper.
Additionally, we need to ensure that the {@link module:widget/widget~Widget Widget} plugin is loaded. If you omit it, the elements in the view will have all the classes (e.g. ck-widget) but there will be no "behaviors" loaded (e.g. clicking a widget will not select it).
// simplebox/simpleboxediting.js
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
// ADDED 2 imports
import { toWidget, toWidgetEditable } from '@ckeditor/ckeditor5-widget/src/utils';
import Widget from '@ckeditor/ckeditor5-widget/src/widget';
export default class SimpleBoxEditing extends Plugin {
static get requires() { // ADDED
return [ Widget ];
}
init() {
console.log( 'SimpleBoxEditing#init() got called' );
this._defineSchema();
this._defineConverters();
}
_defineSchema() {
// ...
}
_defineConverters() { // MODIFIED
const conversion = this.editor.conversion;
// <simpleBox> converters
conversion.for( 'upcast' ).elementToElement( {
model: 'simpleBox',
view: {
name: 'section',
classes: 'simple-box'
}
} );
conversion.for( 'dataDowncast' ).elementToElement( {
model: 'simpleBox',
view: {
name: 'section',
classes: 'simple-box'
}
} );
conversion.for( 'editingDowncast' ).elementToElement( {
model: 'simpleBox',
view: ( modelElement, viewWriter ) => {
const section = viewWriter.createContainerElement( 'section', { class: 'simple-box' } );
return toWidget( section, viewWriter, { label: 'simple box widget' } );
}
} );
// <simpleBoxTitle> converters
conversion.for( 'upcast' ).elementToElement( {
model: 'simpleBoxTitle',
view: {
name: 'h1',
classes: 'simple-box-title'
}
} );
conversion.for( 'dataDowncast' ).elementToElement( {
model: 'simpleBoxTitle',
view: {
name: 'h1',
classes: 'simple-box-title'
}
} );
conversion.for( 'editingDowncast' ).elementToElement( {
model: 'simpleBoxTitle',
view: ( modelElement, viewWriter ) => {
// Note: we use a more specialized createEditableElement() method here.
const h1 = viewWriter.createEditableElement( 'h1', { class: 'simple-box-title' } );
return toWidgetEditable( h1, viewWriter );
}
} );
// <simpleBoxDescription> converters
conversion.for( 'upcast' ).elementToElement( {
model: 'simpleBoxDescription',
view: {
name: 'div',
classes: 'simple-box-description'
}
} );
conversion.for( 'dataDowncast' ).elementToElement( {
model: 'simpleBoxDescription',
view: {
name: 'div',
classes: 'simple-box-description'
}
} );
conversion.for( 'editingDowncast' ).elementToElement( {
model: 'simpleBoxDescription',
view: ( modelElement, viewWriter ) => {
// Note: we use a more specialized createEditableElement() method here.
const div = viewWriter.createEditableElement( 'div', { class: 'simple-box-description' } );
return toWidgetEditable( div, viewWriter );
}
} );
}
}
As you can see, the code became much more verbose and far longer. This is because we used lower-level converters. We plan to provide more handy widget conversion utils in the future. Read more (and 👍) in [this ticket](https://github.com/ckeditor/ckeditor5/issues/1228).
You can rebuild your project now and see how your simple box plugin has changed.
{@img assets/img/tutorial-implementing-a-widget-5.png Screenshot of a widget's focus outline.}
You should observe that:
<section>, <h1>, and <div> elements have the contentEditable attribute on them (plus some classes). This attribute tells the browser whether an element is considered "editable". Passing element through toWidget() will make its content non-editable. Conversely, passing it through toWidgetEditable() will make its content editable again.In other words, the simple box instance became much more responsive.
Additionally, if you call editor.getData() you will get the same HTML as before "widgetizing" simple box. That's thanks to using toWidget() and toNestedEditable() only in the editingDowncast pipeline.
This is all that we need from the model and the view layers for now. In terms of "editability" and data input/output its fully functional. Let's now find a way to insert new simple boxes into the document!
A {@link framework/guides/architecture/core-editor-architecture#commands command} is a combination of an action and a state. You can interact with most of the editor features by commands that they expose. This allows not only executing those features (e.g. bolding a fragment of text) but also checking if this action can be executed in the selection's current location as well as observing other state properties (such as whether the currently selected text is bolded).
In case of the simple box the situation is simple:
Let's create a new file insertsimpleboxcommand.js in the simplebox/ directory. We will use the {@link module:engine/model/model~Model#insertContent model.insertContent()} method which will be able to e.g. split a paragraph if you try to insert a simple box in the middle of it (which is not allowed by the schema.
// simplebox/insertsimpleboxcommand.js
import Command from '@ckeditor/ckeditor5-core/src/command';
export default class InsertSimpleBoxCommand extends Command {
execute() {
this.editor.model.change( writer => {
// Insert <simpleBox>*</simpleBox> at the current selection position
// in a way which will result in creating a valid model structure.
this.editor.model.insertContent( createSimpleBox( writer ) );
} );
}
refresh() {
const model = this.editor.model;
const selection = model.document.selection;
const allowedIn = model.schema.findAllowedParent( selection.getFirstPosition(), 'simpleBox' );
this.isEnabled = allowedIn !== null;
}
}
function createSimpleBox( writer ) {
const simpleBox = writer.createElement( 'simpleBox' );
const simpleBoxTitle = writer.createElement( 'simpleBoxTitle' );
const simpleBoxDescription = writer.createElement( 'simpleBoxDescription' );
writer.append( simpleBoxTitle, simpleBox );
writer.append( simpleBoxDescription, simpleBox );
// There must be at least one paragraph for the description to be editable.
// See https://github.com/ckeditor/ckeditor5/issues/1464.
writer.appendElement( 'paragraph', simpleBoxDescription );
return simpleBox;
}
Import the command and register it in the SimpleBoxEditing plugin:
// simplebox/simpleboxediting.js
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
import { toWidget, toWidgetEditable } from '@ckeditor/ckeditor5-widget/src/utils';
import Widget from '@ckeditor/ckeditor5-widget/src/widget';
import InsertSimpleBoxCommand from './insertsimpleboxcommand'; // ADDED
export default class SimpleBoxEditing extends Plugin {
static get requires() {
return [ Widget ];
}
init() {
console.log( 'SimpleBoxEditing#init() got called' );
this._defineSchema();
this._defineConverters();
// ADDED
this.editor.commands.add( 'insertSimpleBox', new InsertSimpleBoxCommand( this.editor ) );
}
_defineSchema() {
// ...
}
_defineConverters() {
// ...
}
}
You can now execute this command in order to insert a new simple box. Calling:
editor.execute( 'insertSimpleBox' );
Should result in:
{@img assets/img/tutorial-implementing-a-widget-6.png Screenshot of a simple box instance inserted at the beginning of the editor content.}
You can also try inspecting the isEnabled property value (or just checking it in CKEditor 5 inspector):
console.log( editor.commands.get( 'insertSimpleBox' ).isEnabled );
It is always true except when the selection is in one place — in other simple box's title. You can also observe that executing the command when the selection is in that place takes no effect.
Let's change one more thing before we will move forward — let's disallow simpleBox inside simpleBoxDescription too. This can be done by {@link module:engine/model/schema~Schema#addChildCheck defining a custom child check}:
// simplebox/simpleboxediting.js
// ... imports
export default class SimpleBoxEditing extends Plugin {
static get requires() {
return [ Widget ];
}
init() {
console.log( 'SimpleBoxEditing#init() got called' );
this._defineSchema();
this._defineConverters();
this.editor.commands.add( 'insertSimpleBox', new InsertSimpleBoxCommand( this.editor ) );
}
_defineSchema() {
const schema = this.editor.model.schema;
schema.register( 'simpleBox', {
// Behaves like a self-contained object (e.g. an image).
isObject: true,
// Allow in places where other blocks are allowed (e.g. directly in the root).
allowWhere: '$block'
} );
schema.register( 'simpleBoxTitle', {
// Cannot be split or left by the caret.
isLimit: true,
allowIn: 'simpleBox',
// Allow content which is allowed in blocks (i.e. text with attributes).
allowContentOf: '$block'
} );
schema.register( 'simpleBoxDescription', {
// Cannot be split or left by the caret.
isLimit: true,
allowIn: 'simpleBox',
// Allow content which is allowed in the root (e.g. paragraphs).
allowContentOf: '$root'
} );
// ADDED
schema.addChildCheck( ( context, childDefinition ) => {
if ( context.endsWith( 'simpleBoxDescription' ) && childDefinition.name == 'simpleBox' ) {
return false;
}
} );
}
_defineConverters() {
// ...
}
}
Now, the command should be disabled also when the selection is inside the description of another simple box instance.
It is time to allow editor users to insert the widget into the content. The best way to do that is through a UI button in the toolbar. You can quickly create one using the {@link module:ui/button/buttonview~ButtonView ButtonView} class brought by the {@link framework/guides/architecture/ui-library UI framework} of CKEditor 5.
The button should execute the command when clicked and become inactive if the widget cannot be inserted in some particular position of the selection (as defined in the schema).
Let us see what it looks like in practice and extend the SimpleBoxUI plugin created earlier:
// simplebox/simpleboxui.js
import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
export default class SimpleBoxUI extends Plugin {
init() {
console.log( 'SimpleBoxUI#init() got called' );
const editor = this.editor;
const t = editor.t;
// The "simpleBox" button must be registered among UI components of the editor
// to be displayed in the toolbar.
editor.ui.componentFactory.add( 'simpleBox', locale => {
// The state of the button will be bound to the widget command.
const command = editor.commands.get( 'insertSimpleBox' );
// The button will be an instance of ButtonView.
const buttonView = new ButtonView( locale );
buttonView.set( {
// The t() function helps localize the editor. All strings enclosed in t() can be
// translated and change when the language of the editor changes.
label: t( 'Simple Box' ),
withText: true,
tooltip: true
} );
// Bind the state of the button to the command.
buttonView.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
// Execute the command when the button is clicked (executed).
this.listenTo( buttonView, 'execute', () => editor.execute( 'insertSimpleBox' ) );
return buttonView;
} );
}
}
The last thing you need to do is tell the editor to display the button in the toolbar. To do that, you will need to slightly modify the code that runs the editor instance and include the button in the {@link module:core/editor/editorconfig~EditorConfig#toolbar toolbar configuration}:
ClassicEditor
.create( document.querySelector( '#editor' ), {
plugins: [ Essentials, Paragraph, Heading, List, Bold, Italic, SimpleBox ],
// Insert the "simpleBox" to the editor toolbar.
toolbar: [ 'heading', 'bold', 'italic', 'numberedList', 'bulletedList', 'simpleBox' ]
} )
.then( editor => {
// ...
} )
.catch( error => {
// ...
} );
Refresh the web page and try it yourself:
{@img assets/img/tutorial-implementing-a-widget-7.png Screenshot of the simple box widget being inserted using the toolbar button.}
You can see the block widget implementation in action in the editor below. You can also check out the full source code of this tutorial if you want to develop your own block widgets.
{@snippet framework/tutorials/block-widget}
The following code contains a complete implementation of the SimpleBox plugin and the code to run the editor. You can paste it into the app.js file and it will run out–of–the–box:
import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials';
import Bold from '@ckeditor/ckeditor5-basic-styles/src/bold';
import Italic from '@ckeditor/ckeditor5-basic-styles/src/italic';
import Heading from '@ckeditor/ckeditor5-heading/src/heading';
import List from '@ckeditor/ckeditor5-list/src/list';
import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph';
import Plugin from '@ckeditor/ckeditor5-core/src/plugin';
import { toWidget, toWidgetEditable } from '@ckeditor/ckeditor5-widget/src/utils';
import Widget from '@ckeditor/ckeditor5-widget/src/widget';
import Command from '@ckeditor/ckeditor5-core/src/command';
import ButtonView from '@ckeditor/ckeditor5-ui/src/button/buttonview';
class SimpleBox extends Plugin {
static get requires() {
return [ SimpleBoxEditing, SimpleBoxUI ];
}
}
class SimpleBoxUI extends Plugin {
init() {
console.log( 'SimpleBoxUI#init() got called' );
const editor = this.editor;
const t = editor.t;
// The "simpleBox" button must be registered among UI components of the editor
// to be displayed in the toolbar.
editor.ui.componentFactory.add( 'simpleBox', locale => {
// The state of the button will be bound to the widget command.
const command = editor.commands.get( 'insertSimpleBox' );
// The button will be an instance of ButtonView.
const buttonView = new ButtonView( locale );
buttonView.set( {
// The t() function helps localize the editor. All strings enclosed in t() can be
// translated and change when the language of the editor changes.
label: t( 'Simple Box' ),
withText: true,
tooltip: true
} );
// Bind the state of the button to the command.
buttonView.bind( 'isOn', 'isEnabled' ).to( command, 'value', 'isEnabled' );
// Execute the command when the button is clicked (executed).
this.listenTo( buttonView, 'execute', () => editor.execute( 'insertSimpleBox' ) );
return buttonView;
} );
}
}
class SimpleBoxEditing extends Plugin {
static get requires() {
return [ Widget ];
}
init() {
console.log( 'SimpleBoxEditing#init() got called' );
this._defineSchema();
this._defineConverters();
this.editor.commands.add( 'insertSimpleBox', new InsertSimpleBoxCommand( this.editor ) );
}
_defineSchema() {
const schema = this.editor.model.schema;
schema.register( 'simpleBox', {
// Behaves like a self-contained object (e.g. an image).
isObject: true,
// Allow in places where other blocks are allowed (e.g. directly in the root).
allowWhere: '$block'
} );
schema.register( 'simpleBoxTitle', {
// Cannot be split or left by the caret.
isLimit: true,
allowIn: 'simpleBox',
// Allow content which is allowed in blocks (i.e. text with attributes).
allowContentOf: '$block'
} );
schema.register( 'simpleBoxDescription', {
// Cannot be split or left by the caret.
isLimit: true,
allowIn: 'simpleBox',
// Allow content which is allowed in the root (e.g. paragraphs).
allowContentOf: '$root'
} );
schema.addChildCheck( ( context, childDefinition ) => {
if ( context.endsWith( 'simpleBoxDescription' ) && childDefinition.name == 'simpleBox' ) {
return false;
}
} );
}
_defineConverters() {
const conversion = this.editor.conversion;
// <simpleBox> converters
conversion.for( 'upcast' ).elementToElement( {
model: 'simpleBox',
view: {
name: 'section',
classes: 'simple-box'
}
} );
conversion.for( 'dataDowncast' ).elementToElement( {
model: 'simpleBox',
view: {
name: 'section',
classes: 'simple-box'
}
} );
conversion.for( 'editingDowncast' ).elementToElement( {
model: 'simpleBox',
view: ( modelElement, viewWriter ) => {
const section = viewWriter.createContainerElement( 'section', { class: 'simple-box' } );
return toWidget( section, viewWriter, { label: 'simple box widget' } );
}
} );
// <simpleBoxTitle> converters
conversion.for( 'upcast' ).elementToElement( {
model: 'simpleBoxTitle',
view: {
name: 'h1',
classes: 'simple-box-title'
}
} );
conversion.for( 'dataDowncast' ).elementToElement( {
model: 'simpleBoxTitle',
view: {
name: 'h1',
classes: 'simple-box-title'
}
} );
conversion.for( 'editingDowncast' ).elementToElement( {
model: 'simpleBoxTitle',
view: ( modelElement, viewWriter ) => {
// Note: we use a more specialized createEditableElement() method here.
const h1 = viewWriter.createEditableElement( 'h1', { class: 'simple-box-title' } );
return toWidgetEditable( h1, viewWriter );
}
} );
// <simpleBoxDescription> converters
conversion.for( 'upcast' ).elementToElement( {
model: 'simpleBoxDescription',
view: {
name: 'div',
classes: 'simple-box-description'
}
} );
conversion.for( 'dataDowncast' ).elementToElement( {
model: 'simpleBoxDescription',
view: {
name: 'div',
classes: 'simple-box-description'
}
} );
conversion.for( 'editingDowncast' ).elementToElement( {
model: 'simpleBoxDescription',
view: ( modelElement, viewWriter ) => {
// Note: we use a more specialized createEditableElement() method here.
const div = viewWriter.createEditableElement( 'div', { class: 'simple-box-description' } );
return toWidgetEditable( div, viewWriter );
}
} );
}
}
class InsertSimpleBoxCommand extends Command {
execute() {
this.editor.model.change( writer => {
// Insert <simpleBox>*</simpleBox> at the current selection position
// in a way which will result in creating a valid model structure.
this.editor.model.insertContent( createSimpleBox( writer ) );
} );
}
refresh() {
const model = this.editor.model;
const selection = model.document.selection;
const allowedIn = model.schema.findAllowedParent( selection.getFirstPosition(), 'simpleBox' );
this.isEnabled = allowedIn !== null;
}
}
function createSimpleBox( writer ) {
const simpleBox = writer.createElement( 'simpleBox' );
const simpleBoxTitle = writer.createElement( 'simpleBoxTitle' );
const simpleBoxDescription = writer.createElement( 'simpleBoxDescription' );
writer.append( simpleBoxTitle, simpleBox );
writer.append( simpleBoxDescription, simpleBox );
// There must be at least one paragraph for the description to be editable.
// See https://github.com/ckeditor/ckeditor5/issues/1464.
writer.appendElement( 'paragraph', simpleBoxDescription );
return simpleBox;
}
ClassicEditor
.create( document.querySelector( '#editor' ), {
plugins: [ Essentials, Bold, Italic, Heading, List, Paragraph, SimpleBox ],
toolbar: [ 'heading', '|', 'bold', 'italic', 'numberedList', 'bulletedList', 'simpleBox' ],
} )
.then( editor => {
console.log( 'Editor was initialized', editor );
window.editor = editor;
} )
.catch( err => {
console.error( err.stack );
} );