Trying to add a second toggle button for my javascript menu

Question

I am really dumb with javascript but I'm trying really hard. I hope someone can help.

I am creating a wordpress theme using the "Underscores" starter theme by Automattic. The theme has a responsive javascript menu with a button that the user must click to show/hide the menu.

I want to add a SECOND button that can trigger the EXACT SAME menu. I tried to copy some of the code in the theme, however the button's expand/collapse feature seems to be dependent on the parent container's ID. So I am trying to create a button that is INDEPENDENT of the parent (a button that I can place in any div). Note, it must trigger the same menu, just an alternative button outside of the parent.

Here is the original HTML code:

 <nav id="site-navigation">
 <button class="menu-toggle" aria-controls="primary-menu" aria-expanded="false"><?php esc_html_e( 'Primary Menu', 'mytheme' ); ?></button>
    <?php wp_nav_menu( array('theme_location' => 'menu-1', 'menu_id' => 'primary-menu') ); ?>
    </nav>

Here is the original Javascript:

( function() {
    var container, button, menu, links, i, len;

    container = document.getElementById( 'site-navigation' );
    if ( ! container ) {
        return;
    }

    button = container.getElementsByTagName( 'button' )[0];
    if ( 'undefined' === typeof button ) {
        return;
    }

    menu = container.getElementsByTagName( 'ul' )[0];

    // Hide menu toggle button if menu is empty and return early.
    if ( 'undefined' === typeof menu ) {
        button.style.display = 'none';
        return;
    }

    menu.setAttribute( 'aria-expanded', 'false' );
    if ( -1 === menu.className.indexOf( 'nav-menu' ) ) {
        menu.className += ' nav-menu';
    }

    button.onclick = function() {
        if ( -1 !== container.className.indexOf( 'toggled' ) ) {
            container.className = container.className.replace( 'toggled', '' );
            button.setAttribute( 'aria-expanded', 'false' );
            menu.setAttribute( 'aria-expanded', 'false' );
        } else {
            container.className += ' toggled';
            button.setAttribute( 'aria-expanded', 'true' );
            menu.setAttribute( 'aria-expanded', 'true' );
        }
    };

    // Get all the link elements within the menu.
    links    = menu.getElementsByTagName( 'a' );

    // Each time a menu link is focused or blurred, toggle focus.
    for ( i = 0, len = links.length; i < len; i++ ) {
        links[i].addEventListener( 'focus', toggleFocus, true );
        links[i].addEventListener( 'blur', toggleFocus, true );
    }

    /**
     * Sets or removes .focus class on an element.
     */
    function toggleFocus() {
        var self = this;

        // Move up through the ancestors of the current link until we hit .nav-menu.
        while ( -1 === self.className.indexOf( 'nav-menu' ) ) {

            // On li elements toggle the class .focus.
            if ( 'li' === self.tagName.toLowerCase() ) {
                if ( -1 !== self.className.indexOf( 'focus' ) ) {
                    self.className = self.className.replace( ' focus', '' );
                } else {
                    self.className += ' focus';
                }
            }

            self = self.parentElement;
        }
    }

    /**
     * Toggles `focus` class to allow submenu access on tablets.
     */
    ( function( container ) {
        var touchStartFn, i,
            parentLink = container.querySelectorAll( '.menu-item-has-children > a, .page_item_has_children > a' );

        if ( 'ontouchstart' in window ) {
            touchStartFn = function( e ) {
                var menuItem = this.parentNode, i;

                if ( ! menuItem.classList.contains( 'focus' ) ) {
                    e.preventDefault();
                    for ( i = 0; i < menuItem.parentNode.children.length; ++i ) {
                        if ( menuItem === menuItem.parentNode.children[i] ) {
                            continue;
                        }
                        menuItem.parentNode.children[i].classList.remove( 'focus' );
                    }
                    menuItem.classList.add( 'focus' );
                } else {
                    menuItem.classList.remove( 'focus' );
                }
            };

            for ( i = 0; i < parentLink.length; ++i ) {
                parentLink[i].addEventListener( 'touchstart', touchStartFn, false );
            }
        }
    }( container ) );
} )();

So, I tried to create an extra variable called "newbutton" that targets the button by ID instead of the tag. The new button's ID is "site-nav-button"

newbutton = document.getElementById( 'site-nav-button' )[0];
    if ( 'undefined' === typeof button ) {
        return;
    }

Then I copied and ammended the following fuction:

newbutton.onclick = function() {
        if ( -1 !== container.className.indexOf( 'toggled' ) ) {
            container.className = container.className.replace( 'toggled', '' );
            newbutton.setAttribute( 'aria-expanded', 'false' );
            menu.setAttribute( 'aria-expanded', 'false' );
        } else {
            container.className += ' toggled';
            newbutton.setAttribute( 'aria-expanded', 'true' );
            menu.setAttribute( 'aria-expanded', 'true' );
        }
    };

Then I copied the button in the HTML and added the new ID to it:

<button id="site-nav-button" class="menu-toggle" aria-controls="primary-menu" aria-expanded="false"><?php esc_html_e( 'Primary Menu', 'mytheme' ); ?></button>

I tried to put this in a different location of my theme but it didn't work. I am super dumb with javascript. What am I missing or getting wrong?

Answer 1

by code you posted seems that you are not declaring variable "newbutton". For example: var newbutton = '';.

I'm not with computer now but this code seems to be correct (If already declared variable).

Try console.log(newbutton) to see if this var is getting the element

EDIT: I'm now at computer and did a test with your code.

The issue is on this line:

newbutton = document.getElementById( 'site-nav-button' )[0];

You should change to:

newbutton = document.getElementById( 'site-nav-button' );

Regarding the way you are declaring variable newbutton, that's correct.

Hope this helps.