Types of toolbar buttons

There are four types of Toolbar Buttons in TinyMCE 5:

Basic button

A basic button triggers its onAction function when clicked.

Config options

Name Value Requirement Description

text

string

optional

Text to display if no icon is found.

icon

string

optional

Name of the icon to be displayed. Must correspond to an icon: in the icon pack, in a custom icon pack, or added using the addIcon API.

tooltip

string

optional

Text for button tooltip.

disabled

boolean

optional

default: false - Represents the button’s state. When true, button is unclickable. Toggled by the button’s API.

onSetup

(api) ⇒ (api) ⇒ void

optional

default: () ⇒ () ⇒ {} - Function invoked when the button is rendered.

onAction

(api) ⇒ void

required

Function invoked when the button is clicked.
See below for details on how to configure onSetup.

API

Name Value Description

isDisabled

() ⇒ boolean

Checks if the button is disabled.

setDisabled

(state: boolean) ⇒ void

Sets the button’s disabled state.

Basic button example and explanation

The following example adds two buttons to the toolbar:

  • TinyMCE

  • HTML

  • JS

  • Edit on CodePen

<textarea id="custom-toolbar-button">
  <p><img style="display: block; margin-left: auto; margin-right: auto;" title="Tiny Logo" src="https://www.tiny.cloud/docs/images/logos/android-chrome-256x256.png" alt="TinyMCE Logo" width="128" height="128" /></p>
  <h2 style="text-align: center;">Welcome to the TinyMCE editor demo!</h2>
  <p>Select a menu item from the listbox above and it will insert contents into the editor at the caret position.</p>

  <h2>Got questions or need help?</h2>
  <ul>
    <li>Our <a href="https://www.tiny.cloud/docs/">documentation</a> is a great resource for learning how to configure TinyMCE.</li>
    <li>Have a specific question? Try the <a href="https://stackoverflow.com/questions/tagged/tinymce" target="_blank" rel="noopener"><code>tinymce</code> tag at Stack Overflow</a>.</li>
    <li>We also offer enterprise grade support as part of <a href="https://www.tiny.cloud/pricing">TinyMCE premium plans</a>.</li>
  </ul>

  <h2>Found a bug?</h2>
  <p>If you think you have found a bug please create an issue on the <a href="https://github.com/tinymce/tinymce/issues">GitHub repo</a> to report it to the developers.</p>

  <h2>Finally ...</h2>
  <p>Don't forget to check out our other product <a href="http://www.plupload.com" target="_blank">Plupload</a>, your ultimate upload solution featuring HTML5 upload support.</p>
  <p>Thanks for supporting TinyMCE! We hope it helps you and your users create great content.
    <br>All the best from the TinyMCE team.</p>
</textarea>
tinymce.init({
  selector: 'textarea#custom-toolbar-button',
  toolbar: 'customInsertButton customDateButton',
  setup: function (editor) {

    editor.ui.registry.addButton('customInsertButton', {
      text: 'My Button',
      onAction: function (_) {
        editor.insertContent('&nbsp;<strong>It\'s my button!</strong>&nbsp;');
      }
    });

    var toTimeHtml = function (date) {
      return '<time datetime="' + date.toString() + '">' + date.toDateString() + '</time>';
    };

    editor.ui.registry.addButton('customDateButton', {
      icon: 'insert-time',
      tooltip: 'Insert Current Date',
      disabled: true,
      onAction: function (_) {
        editor.insertContent(toTimeHtml(new Date()));
      },
      onSetup: function (buttonApi) {
        var editorEventCallback = function (eventApi) {
          buttonApi.setDisabled(eventApi.element.nodeName.toLowerCase() === 'time');
        };
        editor.on('NodeChange', editorEventCallback);

        /* onSetup should always return the unbind handlers */
        return function (buttonApi) {
          editor.off('NodeChange', editorEventCallback);
        };
      }
    });
  },
  content_style: 'body { font-family:Helvetica,Arial,sans-serif; font-size:14px }'
});

The first button inserts "It’s my button!" into the editor when clicked. The second button is an example of how onSetup works. This button inserts a time element containing the current date into the editor using a toTimeHtml() helper function - a simplified version of TinyMCE’s insertdatetime plugin.

In this example an icon from the insertdatetime plugin is used to demonstrate how to use a registered icon. disabled is set to true so that the button is disabled when it is first rendered.

onSetup is used to listen to the editor’s NodeChange event to disable the button when the cursor is inside a time element (or "node"). This ensures it is not possible to insert a time element into another time element.

Toggle button

A toggle button triggers an action when clicked but also has a concept of state. This means it can be toggled on and off. A toggle button gives the user visual feedback for its state through CSS styling. An example of this behavior is the Bold button that is highlighted when the cursor is in a word with bold formatting.

Config options

Name Value Requirement Description

text

string

optional

Text to display if no icon is found.

icon

string

optional

Name of the icon to be displayed. Must correspond to an icon: in the icon pack, in a custom icon pack, or added using the addIcon API.

tooltip

string

optional

Text for button tooltip.

disabled

boolean

optional

default: false - Represents the button’s state. When true, button is unclickable. Toggled by the button’s API.

active

boolean

optional

default: false - Represents the button’s state. When true, button is highlighted. Toggled by the button’s API.

onSetup

(api) ⇒ (api) ⇒ void

optional

default: () ⇒ () ⇒ {} - Function invoked when the button is rendered.

onAction

(api) ⇒ void

required

Function invoked when the button is clicked.
See below for details on how to configure onSetup.

API

Name Value Description

isDisabled

() ⇒ boolean

Checks if a button is disabled.

setDisabled

(state: boolean) ⇒ void

Sets the button’s disabled state.

isActive

() ⇒ boolean

Checks if the button is on.

setActive

(state: boolean) ⇒ void

Sets the button’s toggle state.

Toggle button example and explanation

  • TinyMCE

  • HTML

  • JS

  • Edit on CodePen

<textarea id="custom-toolbar-toggle-button">
  <p><img style="display: block; margin-left: auto; margin-right: auto;" title="Tiny Logo" src="https://www.tiny.cloud/docs/images/logos/android-chrome-256x256.png" alt="TinyMCE Logo" width="128" height="128" /></p>
  <h2 style="text-align: center;">Welcome to the TinyMCE editor demo!</h2>
  <p>Select a menu item from the listbox above and it will insert contents into the editor at the caret position.</p>

  <h2>Got questions or need help?</h2>
  <ul>
    <li>Our <a href="https://www.tiny.cloud/docs/">documentation</a> is a great resource for learning how to configure TinyMCE.</li>
    <li>Have a specific question? Try the <a href="https://stackoverflow.com/questions/tagged/tinymce" target="_blank" rel="noopener"><code>tinymce</code> tag at Stack Overflow</a>.</li>
    <li>We also offer enterprise grade support as part of <a href="https://www.tiny.cloud/pricing">TinyMCE premium plans</a>.</li>
  </ul>

  <h2>Found a bug?</h2>
  <p>If you think you have found a bug please create an issue on the <a href="https://github.com/tinymce/tinymce/issues">GitHub repo</a> to report it to the developers.</p>

  <h2>Finally ...</h2>
  <p>Don't forget to check out our other product <a href="http://www.plupload.com" target="_blank">Plupload</a>, your ultimate upload solution featuring HTML5 upload support.</p>
  <p>Thanks for supporting TinyMCE! We hope it helps you and your users create great content.
    <br>All the best from the TinyMCE team.</p>
</textarea>
tinymce.init({
  selector: 'textarea#custom-toolbar-toggle-button',
  toolbar: 'customStrikethrough customToggleStrikethrough',
  setup: function (editor) {
    editor.ui.registry.addToggleButton('customStrikethrough', {
      text: 'Strikethrough',
      onAction: function (api) {
        editor.execCommand('mceToggleFormat', false, 'strikethrough');
        api.setActive(!api.isActive());
      }
    });

    editor.ui.registry.addToggleButton('customToggleStrikethrough', {
      icon: 'strike-through',
      onAction: function (_) {
        editor.execCommand('mceToggleFormat', false, 'strikethrough');
      },
      onSetup: function (api) {
        editor.formatter.formatChanged('strikethrough', function (state) {
          api.setActive(state);
        });
      }
    });
  },
  content_style: 'body { font-family:Helvetica,Arial,sans-serif; font-size:14px }'
});

The example above adds two custom strikethrough buttons with the same onAction configuration. The configuration uses editor.execCommand(command, ui, args) to execute mceToggleFormat. This editor method toggles the specified format on and off, but only works for formats that are already registered with the editor. In this example, strikethrough is the registered format.

The first button applies and removes strikethrough formatting, and its state toggles on click using api.setActive(!api.isActive()). However, the expected behaviour is that the button’s state will reflect whether the selected content has strikethrough formatting. For example, if the cursor is moved into editor content that has strikethrough formatting the button will become active and if it is moved into content that does not have strikethrough formatting the button will become inactive. The first button in the example does not do this, since its state only toggles when the button is clicked.

To achieve this, the second button uses onSetup to register a callback for strikethrough content using editor.formatter.formatChanged(formatName, callback). This method executes the specified callback function when the selected content has the specified formatting.

The format name given to mceToggleFormat via editor.execCommand(command, ui, args) and to editor.formatter.formatChanged(formatName, callback) is the same.

The callback given to editor.formatter.formatChanged is a function that takes a state boolean representing whether the currently selected content contains the applied format. This state boolean is used to set the button’s active state to match if the selected content has the specified formatting by using api.setActive(state) from the button’s API. This ensures the customToggleStrikethrough button is only active when the selected content contains the strikethrough formatting.

This feature is only available for TinyMCE 5.9 and later.

For formats that require variables, the editor.formatter.formatChanged function takes two extra arguments: similar and vars.

When the similar argument is true, similar formats will all be treated as the same by formatChanged. Similar formats are those with the same formatName but different variables. This argument will default to false.

The vars argument controls which variables are used to match the content when determining whether to run the callback. This argument is only used when similar is false.

A toolbar menu button is a toolbar button that opens a menu when clicked. This menu can also contain submenus. This is useful for grouping together actions that would otherwise be several buttons on the toolbar. It can also be used to reduce visual clutter and save UI space, as menubar menu items and some toolbar buttons could be moved into a toolbar menu button. Potentially, all menubar menu items could be moved into toolbar menu buttons, allowing for the editor to be used without a menubar at all.

For example: The table plugin’s table toolbar button opens a menu similar to the menubar Table menu.

Config options

Name Value Requirement Description

fetch

(success: (menu) ⇒ void) ⇒ void

required

Function that takes a callback which must be passed the list of options for the button’s dropdown.

text

string

optional

Text to display if no icon is found.

icon

string

optional

Name of the icon to be displayed. Must correspond to an icon: in the icon pack, in a custom icon pack, or added using the addIcon API.

tooltip

string

optional

Text for button tooltip.

onSetup

(api) ⇒ (api) ⇒ void

optional

default: () ⇒ () ⇒ {} - Function that’s invoked when the button is rendered.
See below for details on how to configure onSetup.

API

Name Value Description

isDisabled

() ⇒ boolean

Checks if the button is disabled.

setDisabled

(state: boolean) ⇒ void

Sets the button’s disabled state.

Menu button example and explanation

The following is a simple toolbar menu button example:

  • TinyMCE

  • HTML

  • JS

  • Edit on CodePen

<textarea id="custom-toolbar-menu-button">
  <p><img style="display: block; margin-left: auto; margin-right: auto;" title="Tiny Logo" src="https://www.tiny.cloud/docs/images/logos/android-chrome-256x256.png" alt="TinyMCE Logo" width="128" height="128" /></p>
  <h2 style="text-align: center;">Welcome to the TinyMCE editor demo!</h2>
  <p>Select a menu item from the listbox above and it will insert contents into the editor at the caret position.</p>

  <h2>Got questions or need help?</h2>
  <ul>
    <li>Our <a href="https://www.tiny.cloud/docs/">documentation</a> is a great resource for learning how to configure TinyMCE.</li>
    <li>Have a specific question? Visit the <a href="https://support.tiny.cloud">Support Portal</a>.</li>
    <li>We also offer enterprise grade support as part of <a href="https://www.tiny.cloud/pricing">TinyMCE premium plans</a>.</li>
  </ul>

  <h2>Found a bug?</h2>
  <p>If you think you have found a bug please create an issue on the <a href="https://github.com/tinymce/tinymce/issues">GitHub repo</a> to report it to the developers.</p>

  <h2>Finally ...</h2>
  <p>Don't forget to check out our other product <a href="http://www.plupload.com" target="_blank">Plupload</a>, your ultimate upload solution featuring HTML5 upload support.</p>
  <p>Thanks for supporting TinyMCE! We hope it helps you and your users create great content.
    <br>All the best from the TinyMCE team.</p>
</textarea>
tinymce.init({
  selector: 'textarea#custom-toolbar-menu-button',
  height: 500,
  toolbar: 'mybutton',

  setup: function (editor) {
    /* Menu items are recreated when the menu is closed and opened, so we need
       a variable to store the toggle menu item state. */
    var toggleState = false;

    /* example, adding a toolbar menu button */
    editor.ui.registry.addMenuButton('mybutton', {
      text: 'My button',
      fetch: function (callback) {
        var items = [
          {
            type: 'menuitem',
            text: 'Menu item 1',
            onAction: function () {
              editor.insertContent('&nbsp;<em>You clicked menu item 1!</em>');
            }
          },
          {
            type: 'nestedmenuitem',
            text: 'Menu item 2',
            icon: 'user',
            getSubmenuItems: function () {
              return [
                {
                  type: 'menuitem',
                  text: 'Sub menu item 1',
                  icon: 'unlock',
                  onAction: function () {
                    editor.insertContent('&nbsp;<em>You clicked Sub menu item 1!</em>');
                  }
                },
                {
                  type: 'menuitem',
                  text: 'Sub menu item 2',
                  icon: 'lock',
                  onAction: function () {
                    editor.insertContent('&nbsp;<em>You clicked Sub menu item 2!</em>');
                  }
                }
              ];
            }
          },
          {
            type: 'togglemenuitem',
            text: 'Toggle menu item',
            onAction: function () {
              toggleState = !toggleState;
              editor.insertContent('&nbsp;<em>You toggled a menuitem ' + (toggleState ? 'on' : 'off') + '</em>');
            },
            onSetup: function (api) {
              api.setActive(toggleState);
              return function() {};
            }
          }
        ];
        callback(items);
      }
    });

  },
  content_style: 'body { font-family:Helvetica,Arial,sans-serif; font-size:14px }'
});

This example configures a toolbar menu button with the label My Button that opens the specified menu when clicked. The top-level menu contains two items. The first menu item inserts content when clicked and the second menu item opens a submenu containing two menu items which insert content when clicked.

The fetch function is called when the toolbar menu button’s menu is opened. It is a function that takes a callback and passes it an array of menu items to be rendered in the drop-down menu. This allows for asynchronous fetching of the menu items.

Use the following demo here for help using the menu toolbar button.

Split button

A split button contains a basic button and a menu button, wrapped up into one toolbar item. Clicking the menu button section opens a dropdown list. The basic button section and the menu items can be configured to trigger different actions when clicked.

Config options

Name Value Target component Requirement Description

text

string

Primary button

optional

Text displayed if no icon is found.

icon

string

Primary button

optional

Name of the icon to be displayed. Must correspond to an icon: in the icon pack, in a custom icon pack, or added using the addIcon API.

onAction

(api) ⇒ void

Primary button

required

Function invoked when the basic button section is clicked.

select

(value: string) ⇒ boolean

Choice menu items

optional

default: false - Function run on each option when the menu is opened to determine if it should be highlighted as active.

columns

number or 'auto'

Drop-down menu

optional

default: 1 - Number of columns for the list of options. When set to more than 1 column, only the icon for each item will be shown.

fetch

(success: (menu) ⇒ void) ⇒ void

Drop-down menu

required

A callback function that should be passed a list of choice menu items for the dropdown menu.

onItemAction

(api, value) ⇒ void

Choice menu items

required

Function invoked when a dropdown list option is clicked. The value is passed from the selected choice menu item.

onSetup

(api) ⇒ (api) ⇒ void

All

optional

default: () ⇒ () ⇒ {} - Function invoked when the button is rendered.
See below for details on how to configure onSetup.

API

Name Value Description

isDisabled

() ⇒ boolean

Checks if button is disabled.

setDisabled

(state: boolean) ⇒ void

Sets the button’s disabled state.

isActive

() ⇒ boolean

Checks the button’s toggle state.

setActive

(state: boolean) ⇒ void

Sets the button’s toggle state.

Split button example and explanation

The following example sets up a split button with a text label and a static dropdown menu.

  • TinyMCE

  • HTML

  • JS

  • Edit on CodePen

<textarea id="custom-toolbar-split-button">
  <p><img style="display: block; margin-left: auto; margin-right: auto;" title="Tiny Logo" src="https://www.tiny.cloud/docs/images/logos/android-chrome-256x256.png" alt="TinyMCE Logo" width="128" height="128" /></p>
  <h2 style="text-align: center;">Welcome to the TinyMCE editor demo!</h2>
  <p>Select a menu item from the listbox above and it will insert contents into the editor at the caret position.</p>

  <h2>Got questions or need help?</h2>
  <ul>
    <li>Our <a href="https://www.tiny.cloud/docs/">documentation</a> is a great resource for learning how to configure TinyMCE.</li>
    <li>Have a specific question? Try the <a href="https://stackoverflow.com/questions/tagged/tinymce" target="_blank" rel="noopener"><code>tinymce</code> tag at Stack Overflow</a>.</li>
    <li>We also offer enterprise grade support as part of <a href="https://www.tiny.cloud/pricing">TinyMCE premium plans</a>.</li>
  </ul>

  <h2>Found a bug?</h2>
  <p>If you think you have found a bug please create an issue on the <a href="https://github.com/tinymce/tinymce/issues">GitHub repo</a> to report it to the developers.</p>

  <h2>Finally ...</h2>
  <p>Don't forget to check out our other product <a href="http://www.plupload.com" target="_blank">Plupload</a>, your ultimate upload solution featuring HTML5 upload support.</p>
  <p>Thanks for supporting TinyMCE! We hope it helps you and your users create great content.
    <br>All the best from the TinyMCE team.</p>
</textarea>
tinymce.init({
  selector: 'textarea#custom-toolbar-split-button',
  toolbar: 'myButton',
  menubar: false,
  setup: function (editor) {
    editor.ui.registry.addSplitButton('myButton', {
      text: 'My Button',
      icon: 'info',
      tooltip: 'This is an example split-button',
      onAction: function () {
        editor.insertContent('<p>You clicked the main button</p>');
      },
      onItemAction: function (api, value) {
        editor.insertContent(value);
      },
      fetch: function (callback) {
        var items = [
          {
            type: 'choiceitem',
            icon: 'notice',
            text: 'Menu item 1',
            value: '&nbsp;<em>You clicked menu item 1!</em>'
          },
          {
            type: 'choiceitem',
            icon: 'warning',
            text: 'Menu item 2',
            value: '&nbsp;<em>You clicked menu item 2!</em>'
          }
        ];
        callback(items);
      }
    });
  },
  content_style: 'body { font-family:Helvetica,Arial,sans-serif; font-size:14px }'
});

A split button is similar to a basic button in that they both require an onAction callback. The onAction callback function should take the button’s API and return nothing. It is called when the basic button section is clicked. In this example, onAction calls editor.insertContent(value) which inserts the given content into the editor.

onItemAction is called when a menu item is clicked. The callback function is passed the split button’s API and the value of the selected menu item. Nothing should be returned. The example calls editor.insertContent(value) to insert the value into the editor’s content.

The fetch function is called whenever the split button’s drop-down menu is opened. It is a function that takes a callback and passes it an array of menu items to be rendered in the button’s drop-down menu. This allows for asynchronous fetching of the menu items.

Choice menu items

Choice menu items are a special type of menu item used for split toolbar button menu items. For information on split buttons, see: Split toolbar buttons.

Config options

Name Value Requirement Description

value

any

required

A value that is passed to onItemAction when the choice menu item is clicked.

text

string

optional

Text to display.

icon

string

optional

Name of the icon to be displayed. Must correspond to an icon: in the icon pack, in a custom icon pack, or added using the addIcon API.

disabled

boolean

optional

default: false - Represents the menu item’s state. When true, the menu item is unclickable. Toggled by the menu item’s API.

shortcut

string

optional

Text to display in the shortcut label. To register a shortcut, see: Add custom shortcuts to TinyMCE.
The icon option for choice menu items was added in TinyMCE 5.3.

For an example of how choice menu items are used in split toolbar buttons, see: Split button example and explanation.

Group toolbar button

This feature is only available for TinyMCE 5.2 and later.

A group toolbar button is a toolbar button that contains a collection of other toolbar buttons that are displayed in a pop-up when clicked. The style of toolbar shown is based on the current toolbar mode. For example, if toolbar_mode is set to floating, the toolbar group pop-up will appear in a floating shelf.

The group toolbar button is only supported when using the floating toolbar mode. If the toolbar_groups option is used with other toolbar modes, the toolbar group button will not be displayed and a warning message will be printed in the console.

Config options

Name Value Requirement Description

text

string

optional

Text to display if no icon is found.

icon

string

optional

Name of the icon to be displayed. Must correspond to an icon: in the icon pack, in a custom icon pack, or added using the addIcon API.

tooltip

string

optional

Text for button tooltip.

items

string or LabelledToolbar[]

required

A string of space separated toolbar button names, or an array of labelled toolbar buttons.

onSetup

(api) ⇒ (api) ⇒ void

optional

default: () ⇒ () ⇒ {} - Function that’s invoked when the button is rendered.
See below for details on how to configure onSetup.

API

Name Value Description

isDisabled

() ⇒ boolean

Checks if the button is disabled.

setDisabled

(state: boolean) ⇒ void

Sets the button’s disabled state.

Group toolbar button example and explanation

The following is a simple group toolbar button example:

  • TinyMCE

  • HTML

  • JS

  • Edit on CodePen

<textarea id="custom-toolbar-group-button">
  <p><img style="display: block; margin-left: auto; margin-right: auto;" title="Tiny Logo" src="https://www.tiny.cloud/docs/images/logos/android-chrome-256x256.png" alt="TinyMCE Logo" width="128" height="128" /></p>
  <h2 style="text-align: center;">Welcome to the TinyMCE editor demo!</h2>
  <p>Select a menu item from the listbox above and it will insert contents into the editor at the caret position.</p>

  <h2>Got questions or need help?</h2>
  <ul>
    <li>Our <a href="https://www.tiny.cloud/docs/">documentation</a> is a great resource for learning how to configure TinyMCE.</li>
    <li>Have a specific question? Visit the <a href="https://support.tiny.cloud">Support Portal</a>.</li>
    <li>We also offer enterprise grade support as part of <a href="https://www.tiny.cloud/pricing">TinyMCE premium plans</a>.</li>
  </ul>

  <h2>Found a bug?</h2>
  <p>If you think you have found a bug please create an issue on the <a href="https://github.com/tinymce/tinymce/issues">GitHub repo</a> to report it to the developers.</p>

  <h2>Finally ...</h2>
  <p>Don't forget to check out our other product <a href="http://www.plupload.com" target="_blank">Plupload</a>, your ultimate upload solution featuring HTML5 upload support.</p>
  <p>Thanks for supporting TinyMCE! We hope it helps you and your users create great content.
    <br>All the best from the TinyMCE team.</p>
</textarea>
tinymce.init({
  selector: 'textarea#custom-toolbar-group-button',
  height: 500,
  toolbar_mode: 'floating',
  toolbar: 'alignment',

  setup: function (editor) {

    /* example, adding a group toolbar button */
    editor.ui.registry.addGroupToolbarButton('alignment', {
      icon: 'align-left',
      tooltip: 'Alignment',
      items: 'alignleft aligncenter alignright | alignjustify'
    });

  },
  content_style: 'body { font-family:Helvetica,Arial,sans-serif; font-size:14px }'
});

The example above configures a custom alignment group toolbar button. When clicked the button will show a floating shelf containing the align left, center, right and justify toolbar buttons.

onSetup explanation

onSetup is a complex property. It takes a function that is passed the component’s API and should return a callback that is passed the component’s API and returns nothing. This occurs because onSetup runs whenever the component is rendered, and the returned callback is executed when the component is destroyed. This is essentially an onTeardown handler, and can be used to unbind events and callbacks.

To clarify, in code onSetup may look like this:

onSetup: function (api) {
  // Do something here on component render, like set component properties or bind an event listener

return function (api) {
    // Do something here on teardown, like unbind an event listener
  };
};

To bind a callback function to an editor event use editor.on(eventName, callback). To unbind an event listener use editor.off(eventName, callback). Any event listeners should be unbound in the teardown callback. The only editor event which does not need to be unbound is init e.g. editor.on('init', callback).

  • The callback function for editor.off() should be the same function passed to editor.on(). For example, if a editorEventCallback function is bound to the NodeChange event when the button is created, onSetup should return function (api) { editor.off('NodeChange', editorEventCallback) }.

  • If onSetup does not have any event listeners or only listens to the init event, onSetup can return an empty function e.g. return function () {};.