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headings.md 6.3 KB


category: features

Headings

{@snippet build-classic-source}

The {@link module:heading/heading~Heading} feature enables support for headings. These are used by the creators to structure their documents and aid both the readers making the reading easier and more organized and the search indexers scanning for crucial information.

This feature is enabled by default in all builds.

Heading levels

By default this feature is configured to support <h2>, <h3> and <h4> elements which are named: "Heading 1", "Heading 2" and "Heading 3", respectively. The rationale behind starting from <h2> is that <h1> should be reserved for the {@link features/title page's main title} and the page content will usually start from <h2>.

Support for adding a document title is provided through the {@link module:heading/title~Title} plugin. This plugin is optional and needs to be {@link builds/guides/integration/installing-plugins added to your editor build}. When it is enabled, a `<h1>` element pasted into the editor will be rendered as the {@link features/title document title}.

By default, when your editor build does not include the title plugin, a <h1> element pasted into the rich-text editor is converted to <h2> ("Heading 1").

You can read more about why the editor should not create `<h1>` elements for content headings in the [Headings section of Editor Recommendations](http://ckeditor.github.io/editor-recommendations/features/headings.html).

Demo

{@snippet features/default-headings}

Related features

There are more CKEditor 5 features that can help you format your content:

  • {@link features/basic-styles Basic font styles} – The essentials, like bold, italic and others.
  • {@link features/title Document title} – Clearly divide your content into a title and body.
  • {@link features/indent Block indentation feature} – Set indentation for text blocks such as paragraphs or lists.
  • {@link features/lists Lists} – Organize your content better with ordered and unordered list you can style.
  • {@link features/remove-format Remove format} – Easily clean basic text formatting.

Configuration

Configuring heading levels

It is, of course, possible to configure which heading levels the editor should support and how they should be named in the Headings dropdown. Use the {@link module:heading/heading~HeadingConfig#options heading.options} configuration option to do so.

For example, the following editor will support only two levels of headings — <h1> and <h2>:

<div id="editor">
	<h1>Heading 1</h1>
	<h2>Heading 2</h2>
	<p>This is <a href="https://ckeditor.com">CKEditor 5</a>.</p>
</div>
ClassicEditor
	.create( document.querySelector( '#editor' ), {
		heading: {
			options: [
				{ model: 'paragraph', title: 'Paragraph', class: 'ck-heading_paragraph' },
				{ model: 'heading1', view: 'h1', title: 'Heading 1', class: 'ck-heading_heading1' },
				{ model: 'heading2', view: 'h2', title: 'Heading 2', class: 'ck-heading_heading2' }
			]
		}
	} )
	.then( ... )
	.catch( ... );

{@snippet features/custom-heading-levels}

Configuring custom heading elements

It is also possible to define fully custom elements for headings by using the {@link module:engine/conversion/conversion~ConverterDefinition advanced format} of the {@link module:heading/heading~HeadingConfig#options heading.options} configuration option.

For example, the following editor will support the following two heading options at the same time: <h2 class="fancy"> and <h2>:

<style>
	// Styles for the heading in the content and for the dropdown item.
	h2.fancy, .ck-heading_heading2_fancy {
		color: #ff0050;
		font-size: 17px;
	}
</style>

<div id="snippet-custom-heading-levels">
	<h1>Heading 1</h1>
	<h2>Heading 2</h2>
	<h2 class="fancy">Fancy Heading 2</h2>
	<p>This is <a href="https://ckeditor.com">CKEditor 5</a>.</p>
</div>
ClassicEditor
	.create( document.querySelector( '#editor' ), {
		heading: {
			options: [
				{ model: 'paragraph', title: 'Paragraph', class: 'ck-heading_paragraph' },
				{ model: 'heading1', view: 'h1', title: 'Heading 1', class: 'ck-heading_heading1' },
				{ model: 'heading2', view: 'h2', title: 'Heading 2', class: 'ck-heading_heading2' },
				{
					model: 'headingFancy',
					view: {
						name: 'h2',
						classes: 'fancy'
					},
					title: 'Heading 2 (fancy)',
					class: 'ck-heading_heading2_fancy',

					// It needs to be converted before the standard 'heading2'.
					converterPriority: 'high'
				}
			]
		}
	} )
	.then( ... )
	.catch( ... );

{@snippet features/custom-heading-elements}

Installation

This feature is enabled by default in all builds. The installation instructions are for developers interested in building their own, custom editor.

To add this feature to your editor install the @ckeditor/ckeditor5-heading package:

npm install --save @ckeditor/ckeditor5-heading

And add it to your plugin list and toolbar configuration:

import Heading from '@ckeditor/ckeditor5-heading/src/heading';

ClassicEditor
	.create( document.querySelector( '#editor' ), {
		plugins: [ Heading, ... ],
		toolbar: [ 'heading', ... ]
	} )
	.then( ... )
	.catch( ... );

Read more about {@link builds/guides/integration/installing-plugins installing plugins}.

Common API

The {@link module:heading/heading~Heading} plugin registers:

  • The 'heading' dropdown.
  • The 'heading' command that accepts value based on the {@link module:heading/heading~HeadingConfig#options heading.options} configuration option.

    You can turn the currently selected block(s) to headings by executing one of these commands:

    editor.execute( 'heading', { value: 'heading2' } );
    

We recommend using the official {@link framework/guides/development-tools#ckeditor-5-inspector CKEditor 5 inspector} for development and debugging. It will give you tons of useful information about the state of the editor such as internal data structures, selection, commands, and many more.

Contribute

The source code of the feature is available on GitHub in https://github.com/ckeditor/ckeditor5/tree/master/packages/ckeditor5-heading.