add new save button on page edit, to do something additional on save

CustomPageSave.module

<?php

/**
 * Adding other types of save buttons for page edit form.
 *
 * ProcessWire 2.x
 * Copyright (C) 2010 by Ryan Cramer
 * Licensed under GNU/GPL v2, see LICENSE.TXT
 *
 * http://www.processwire.com
 * http://www.ryancramer.com
 *
 */

class CustomPageSave extends WireData implements Module {

    /**
     * getModuleInfo is a module required by all modules to tell ProcessWire about them
     *
     * @return array
     *
     */
    public static function getModuleInfo() {

        return array(
            'title' => 'CustomPageSave',
            'version' => 1,
            'summary' => 'Example for adding other save buttons to page edit',
            'href' => 'http://www.processwire.com',
            'singular' => true,
            'autoload' => true,
            );
    }

    /**
     * Initialize the module
     *
     * ProcessWire calls this when the module is loaded. For 'autoload' modules, this will be called
     * when ProcessWire's API is ready. As a result, this is a good place to attach hooks.
     *
     */
    public function init() {

        $this->addHookAfter("ProcessPageEdit::buildForm", $this, "addSaveButton");

        // tell processwire that this is a page save
        if($this->input->post->submit_save_minor){
            $this->input->post->submit_save = 1;
            // attach hook on page save
            $this->addHookAfter("Pages::saveReady", $this, "hookPageSave");
        }
    }

    public function hookPageSave($event){
        $page = $event->arguments("page");
        if($this->input->post->submit_save_minor){
            // increment an integer field "minor" or do something else
            // this will get saved after this saveReady hook so no need to save here
            $page->minor = $page->minor + 1;
            $this->message("Saved minor");
        }
    }

    public function addSaveButton($event){
        $form = $event->return;

        // new submit button
        $f = $this->modules->InputfieldSubmit;
        $f->attr("name", "submit_save_minor");
        $f->attr("value", "Save minor");

        // add submit button after the regular save button
        $form->insertAfter($f, $form->get("submit_save"));
    }

}