How can the tinyMCE dom be manipulated (offical API does not seem to work)?

Is this possible with a tinymce plugin? I think other ways to access the iframe are not working or not recommended.

I have found this And tried that in the printing mce plugin inside the TinyMCE Advanced plugin but it does not work.

var $ = tinymce.dom.DomQuery;
$('p').attr('attr', 'value').addClass('class');

I have installed the tinymce advanced plugin and tryed adding this lines to the print plugin. The plugin gets executed, the print dialog opens but it just does not to anything to the dom. Does WP has the full version of tinymce?

/**
 * plugin.js
 *
 * Released under LGPL License.
 * Copyright (c) 1999-2015 Ephox Corp. All rights reserved
 *
 * License: http://www.tinymce.com/license
 * Contributing: http://www.tinymce.com/contributing
 */

/*global tinymce:true */


var mce_dom = tinymce.dom.DomQuery;
mce_dom('p').attr('id', 'arve').addClass('arve-html-class');
mce_dom('html').attr('id', 'arve').addClass('arve-html-class');

tinymce.PluginManager.add('print', function(editor) {

    var mce_dom = tinymce.dom.DomQuery;
    mce_dom('p').attr('id', 'arve').addClass('arve-html-class');
    mce_dom('html').attr('id', 'arve').addClass('arve-html-class');

    editor.addCommand('mcePrint', function() {
        editor.getWin().print();
    });

    editor.addButton('print', {
        title: 'Print',
        cmd: 'mcePrint'
    });

    editor.addShortcut('Meta+P', '', 'mcePrint');

    editor.addMenuItem('print', {
        text: 'Print',
        cmd: 'mcePrint',
        icon: 'print',
        shortcut: 'Meta+P',
        context: 'file'
    });
});

Hope You can use fallowing

// Sets class attribute on all paragraphs in the active editor
tinymce.activeEditor.dom.setAttrib(tinymce.activeEditor.dom.select('p'), 'class', 'myclass');

// Sets class attribute on a specific element in the current page
tinymce.dom.setAttrib('mydiv', 'class', 'myclass');

or You can add Id by jquery like this

$('div').find('p').attr('id', 'myid');