This page contains two <tc:script/> tags, one for the CKEditor itself and the other for the initialization in this demo. The <tc:textarea/> contain <tc:dataAttribute name="html-editor" value="ckeditor"/>, to mark this textarea to be used as rich text editor. The initialization is done by the init-ckeditor.js script.

init-ckeditor.js

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
document.addEventListener("DOMContentLoaded", (event) => {
  ClassicEditor.create( document.querySelector( "textarea[data-html-editor=ckeditor]" ) )
      .then( editor => {
        console.log( editor );
      } )
      .catch( error => {
        console.error( error );
      } );
});

<?xml version="1.0" encoding="UTF-8"?>

<!--
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
-->

<ui:composition template="/main.xhtml"
                xmlns="http://www.w3.org/1999/xhtml"
                xmlns:f="http://java.sun.com/jsf/core"
                xmlns:tc="http://myfaces.apache.org/tobago/component"
                xmlns:ui="http://java.sun.com/jsf/facelets">

  <tc:script file="https://cdn.ckeditor.com/ckeditor5/25.0.0/classic/ckeditor.js"/>
  <tc:script file="#{request.contextPath}/content/20-component/110-wysiwyg/01-ckeditor/init-ckeditor.js"/>

  <ui:param name="title" value="#{demoBundle.ckeditor}"/>
  <tc:section label="Setup">
    <p>
      This demo uses the CDN of CKEditor as a showcase.
      There are other integration possibilities.
      For more information to setup see
      <tc:link image="fa-external-link" link="https://ckeditor.com//" label="CKEditor"/>.
    </p>

    <p>
      <tc:badge
          value="Only working with internet access of the browser, because of the use of a CDN."
          markup="info"/>
    </p>

    <p>
      The setup needs entries in <code>tobago-config.xml</code> for CSP.
      More infomation about these entries you find also on their webside.
    </p>

    <p>
      <tc:badge
          value="Not working with CSP mode='on'! Can be turned off in tobago-config.xml, or configured correctly."
          markup="warning"/>
    </p>

    <p>
      This page contains two <code class="language-markup">&lt;tc:script/></code> tags,
      one for the CKEditor itself and the other for the initialization in this demo.
      The <code class="language-markup">&lt;tc:textarea/></code> contain
      <code class="language-markup">&lt;tc:dataAttribute name="html-editor" value="ckeditor"/></code>,
      to mark this textarea to be used as rich text editor. The initialization is done by the
      <code>init-ckeditor.js</code> script.
    </p>

    <tc:box id="sourceCodeBox" label="init-ckeditor.js" collapsed="true" collapsedMode="hidden">
      <f:facet name="bar">
        <tc:buttons>
          <tc:button label="show" omit="true">
            <tc:operation name="show" for="sourceCodeBox"/>
          </tc:button>
          <tc:button label="hide" omit="true">
            <tc:operation name="hide" for="sourceCodeBox"/>
          </tc:button>
        </tc:buttons>
      </f:facet>
      <pre><code class="language-javascript"><tc:out value="#{ckeditorController.source}"/></code></pre>
    </tc:box>

    <tc:textarea value="#{ckeditorController.text}">
      <tc:dataAttribute name="html-editor" value="ckeditor"/>
    </tc:textarea>
    <tc:button label="Submit"/>
  </tc:section>
</ui:composition>