<textarea id="artikel">
  <p><a href="http://www.rumahcode.org/blog/post/30/Tutorial-Menambahkan-class-image-pada-tinymce-text-editor">Tutorial Menambahkan class image pada tinymce text editor@rumah Code</a></p>
</textarea>
tinymce.init({
  selector: '#artikel',
  height: 500,
  plugins: [
    "advlist autolink lists link image charmap print preview anchor",
    "searchreplace visualblocks code fullscreen",
    "insertdatetime media table paste imagetools wordcount"
  ],
  toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image",
  content_css: [
    '//fonts.googleapis.com/css?family=Lato:300,300i,400,400i',
    '//www.tiny.cloud/css/codepen.min.css'
  ],
  image_class_list: [
		{title: 'None', value: ''},
		{title: 'Fluid', value: 'img-fluid'},
		{title: 'Thumbnail', value: 'rounded img-thumbnail'},
		{title: 'Thumbnail FL', value: 'rounded img-thumbnail float-left'},
		{title: 'Thumbnail FR', value: 'rounded img-thumbnail float-right'}
	  ]
});

External CSS

  1. https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/tinymce/5.1.2/tinymce.min.js