Source: navbar.js

/**
 * Navbar Component<BR>
 * <BR><BR><img src=/tk/lib/components/w/img/navbar.png width=30% style="border:1px lime dashed;padding:20px">
 * <BR><BR><a href="/tk/lib/components/w/html/navbar.html">DEMO</a>
 */
class Navbar extends HTMLElement {
    constructor() {
        wc.group("Navbar.constructor")
	
        super();

        wc.groupEnd();
    };
    
    /**
     * Set observable values here. When Changed, attributeChangedCallback is invoked
     * @observedAttributes
     */
    static get observedAttributes() {
        wc.group("Navbar.observedAttributes");

	this.observables = [];

        wc.groupEnd();
        return this.observables;
    };

    /**
     * Called when this is attached to DOM
     * @connectedCallback. 
     */
    connectedCallback() {
        wc.group("Navbar.connectedCallback")
	
	let self = this;

	// ADD A RANDOM ID IF NONE EXIST
	if (!this.id) {
	    this.id = this.constructor.name.toLowerCase() + "-" + wc.uid();
	}

	// GET PROPERTIES AND INTERESTING ELEMENTS
	this._initialize();

	// ADD COMPONENT MARKTOP
	this.innerHTML = this._template()

	if (this.properties.cfg) {
	    this.configure();
	}

	// SUBSCRIBE TO REQUESTS FROM CLIENTS
	wc.subscribe(this.id, function(e) {
	    self._request(e)
	});

	// ADD STATS AND OTHER FINAL STUFF
	this._finalize();

	ga('send', {'hitType': 'event','eventCategory': 'wc-connected','eventAction': 'connected','eventLabel': this.properties.cname, 'eventValue':JSON.stringify({'env':wcENV,'app':wcAPP,'url':wcURL})});

        wc.groupEnd();
    };

    /**
     * Initial Markup
     * @private
     * @_template
     */
    _template() {
        wc.group("Navbar.template");
	
	var temp = `
<div class="pt-2 pb-2 wc-navbar-container">
    <div class="container">
	<div class="row">
	    <div class="col-12">
		<nav class="navbar navbar-expand-lg padding-0">
		    <a class="navbar-brand" id="nav-brand" url="#">${this.properties.brand || "NAVBAR"}</a>
		    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
			<span class="navbar-toggler-icon"></span>
		    </button>
		    <div class="collapse navbar-collapse" id="navbarNav">
			<ul class="navbar-nav mr-auto wc-navbar-lhs">
			</ul>

			<ul class="navbar-nav  wc-navbar-rhs">
			</ul>
		    </div>
		</nav>
	    </div>
	</div>
    </div>
</div>`

        wc.groupEnd();
        return temp;
    };

    /**
     * Called with .setAttribute(...) function call
     * @attributeChangedCallback
     */
    attributeChangedCallback(attr, oldval, newval) {
        wc.group("Navbar.attributeChangedCallback:", attr, oldval, newval);

	this.properties = this.properties || [];

	let obs = Navbar.observedAttributes;

	for (let i = 0; i < obs.length; i++) {
	    if (newval) {
		this.properties[obs[i]] = newval;
	    }
	}
	
	// YOUR CODE FOR CHANGES GO HERE (MAYBE NULL FIRST TIME THROUGH)
	try {
	    switch(attr) 
	    {
		case "header":
		//this.querySelector("h1").innerHTML = newval;
		break;
		
		default:
		break;
	    }
	} catch(e) {
	    wc.warn(e.name + ' > ' + e.message);
	}

        wc.groupEnd();
    };

    /**
     * Stores DOM elements of interest for future use
     * @private
     * @_fetchElements
     */
    _fetchElements() {
	wc.group("Navbar._fetchElements");
	
	this.dom = this.dom || [];
	this.dom.content = this.innerHTML;

	wc.groupEnd();
    };

    /**
     * Component attributes are _fetched and defaults are set if undefined
     * @private
     * @_fetchAttributes
     */
    _fetchAttributes() {
	wc.group("Navbar._fetchAttributes");
	
	this.properties = {
	    uparam	: "",
	    cname	: "Navbar",
	    author	: "Mel M. Heravi, Ph.D.",
	    version	: "1.0"
	};
	
	// SAVE WIDGET SPECIFIC PROPERTIES
	this.propertiesW = [];
	
	// SAVE ALL OTHER PROPERTIES
	let attrs = wc.getAttributes(this)
	
 	for (var key in attrs) {
	    let attr = this.getAttribute(key) || this.properties.key;
	    this.properties[key]  = this.getAttribute(key);
	    this.propertiesW[key] = this.getAttribute(key);
	    wc.log(key + ": " + attrs[key]);
	}

	// SET ALL INITIAL ATTRIBUTES
 	for (var key in this.properties) {
	    switch(key) 
	    {
		case "header":
		break;
		
		default:
		break;
	    }
	}

	wc.log("ATTRIBUTES: ", this.properties);

	wc.groupEnd();
    };

    /**
     * configure the instance object and artifacts
     * @configure
     * @param {string} data use data if exist else use 'this.properties.cfg' parameter
     */
    configure(data) {
	wc.group("Navbar.configure:", data);

	// IF JSON VARIABLE (data) IS PROVIDED
	if (data) {
	    this._process(data);
	} else {
	    let self = this;

	    $.getJSON(this.properties.cfg, function(data) {
		self._process(data);
	    }).fail(function(jqXHR, textStatus, errorThrown) {
		alert("ERROR: INCOMING TEXT " + jqXHR.responseText);
	    });
	}

	wc.groupEnd();
    };

    /**
     * _process the instance object and artifacts
     * @private
     * @_process
     */
    _process(data) {
	wc.group("Navbar._process:", data);
	
	let self = this;
	let lhs = data.lhs || [];
	let rhs = data.rhs || [];
	this.properties.active = this.properties.active || lhs[0].id; // SET DEFAULT ACTIVE PAGE

	// PROCESS LHS ITEMS
	this.lhs = this.querySelector(".navbar ul.wc-navbar-lhs");
	for (var i = 0; i < lhs.length; i++) {
	    $(this.lhs).append(`<li class="nav-item"><a class="nav-link" id="${lhs[i].id}" url="${lhs[i].url || '#'}">${lhs[i].name}</a></li>`);
	}

	// PROCESS LHS ITEMS
	this.rhs = this.querySelector(".navbar ul.wc-navbar-rhs");
	for (var i = 0; i < rhs.length; i++) {
	    $(this.rhs).append(`<li class="nav-item"><a class="nav-link" id="${rhs[i].id}" url="${rhs[i].url || '#'}">${rhs[i].name}</a></li>`);
	}

	// ADD CLICK EVENTS
	$(this.querySelectorAll("a")).on("click", function() {
	    let id = $(this).attr("id");
	    let url = $(this).attr("url");

	    // SET ACTIVE
	    let lis = self.querySelectorAll("li");
	    $(lis).removeClass("active");
	    $(this).parent().addClass("active");

	    wc.publish("wc-navbar", {
		time: new Date().getTime(),
		action: "click",
		id: self.id,
		navid: id,
		url: url
	    });

	    data.background = data.background || "#000";
	    data.color = data.color || "#FFF";
	    data.active = data.active || "red";

	    let cont = self.querySelector(".wc-navbar-container");
	    let as =  self.querySelectorAll("a");
	    let aa =  self.querySelectorAll("li.active");

	    $(cont).css("background", data.background);
	    $(as).css("color", data.color);
	    $(aa).find("a").css("color", data.active);
	});

	// LOAD ACTIVE PAGE NOW
	wc.wait4(`#${this.id} #${this.properties.active}`, () => {
	    let act = this.querySelector("#" + this.properties.active);
	    $(act).click();
	});

	wc.groupEnd();
    };

    /**
     * Initialize component
     * @private
     * @_initialize
     */
    _initialize() {
	wc.group("Navbar._initialize:", this.id);

	// FETCH ALL INTERESTING ELEMENTS
	this._fetchElements();

	// FETCH ALL ATTRIBUTES
	this._fetchAttributes();
	
	wc.groupEnd();
    };

    /**
     * Save data for analytics and final wrap up
     * @private
     * @_finalize
     */
    _finalize() {
	wc.group("Navbar._finalize:", this.id);

	this.classList.add("wc");

	// ADD ANALYTICS HERE
	wc.setStats(this, this.properties.cname, this.properties.version);
	
	// SHOW IT NOW (NO FLICKERS) 
	this.style.visibility = "visible";

	wc.groupEnd();
    };

    /**
     * Invoked When component is removed. Usually with a .remove() function call
     * @disconnectedCallback
     */
    disconnectedCallback() {
        wc.group("Navbar.disconnectedCallback")

	ga('send', {'hitType': 'event','eventCategory': 'wc-disconnected','eventAction': 'disconnected','eventLabel': this.properties.cname, 'eventValue':JSON.stringify({'env':wcENV,'app':wcAPP,'url':wcURL})});

        wc.groupEnd();
    };

    /**
     * Destroy the instance object and artifacts
     * @destroy
     */
    destroy() {
	wc.group("Navbar.destroy");

	// FREE ALL MEMORY
	// you should delete all created objects here
	
	// FREE POINTER
	delete this;
	
	// REMOVE ITEM FROM DOM
	this.parentNode.removeChild(this);

	ga('send', {'hitType': 'event','eventCategory': 'wc-destroyed','eventAction': 'distroy','eventLabel': this.properties.cname, 'eventValue':JSON.stringify({'env':wcENV,'app':wcAPP,'url':wcURL})});

	wc.groupEnd();
    };

    /**
     * @_publish
     */
    _publish(type) {
	wc.group("Navbar._publish:", type);

	wc.publish("wc-navbar", {
	    time: new Date().getTime(),
	    action: type,
	    id: this.id
	});

	wc.groupEnd();
	return true;
    };

    /**
     * @_request
     */
    _request(e) {
	wc.group("Navbar._request:", this.id, JSON.stringify(e.detail));
	
	switch(e.detail.request) 
	{
	    case "open":
	    let link = this.querySelector("#" + e.detail.link);
	    $(link).click();
	    break;

	    default:
	    alert("DO NOT HAVE SUCH REQUEST: " + e.detail.request);
	    break;
	}

	wc.groupEnd();
	return true;
    };

    /**
     * @test
     */
    static test(what) {
	wc.group("Navbar.test:", what);

	switch(what) 
	{
	    case "label":
	    wc.publish("my-navbar", {time:new Date().getTime(), requestor:"my-navbar", request:"label", str:"Hello Mel !"})
	    break;
	}
	
	wc.groupEnd();
	return true;
    }
}

window.customElements.define('wc-navbar', Navbar);

// SO I CAN CALL THE STATIC METHOD GLOBALLY
window.Navbar = Navbar;