Source: panel.js

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

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

	this.observables = [];

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

    /**
     * Called when this is attached to DOM
     * @connectedCallback. 
     */
    connectedCallback() {
        wc.group("Panel.connectedCallback")
	
	// ADD A RANDOM ID IF NONE EXIST
	this.id = this.id || this.constructor.name.toLowerCase() + "-" + wc.uid();

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

	// SHOW THIS COMPONENT
	this._render()

	// CHECK | UPDATE ATTRIBUTES
	this._attributes();
	
	// SUBSCRIBE TO ALL EVENTS OF INTEREST
	this._subscribe();

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

        wc.groupEnd();
    };

    /**
     * Initial Markup
     * @private
     * @_template
     */
    _template() {
        wc.group("Panel.template");
	
	var temp;

	// ADD COMPONENT MARKTOP
	if (wcENV == "prod") {
	    // FOR PRODUCTION (convert part.html to jstr using h2j)
	    temp = `<h1>A BLANK TEMPLATE</h1>`+
		''+
		`<i class="fa fa-home fa-5x"></i>`+
		''+
		`<div class="mt-3">`+
		`    <h1 class="btn btn-lg btn-primary">I AM A BOOTSTRAP BUTTON</h4>`+
		`</div>`;
	} else {
	    // FOR DEVELOPMENT/LOCAL TESTING
	    temp = "<wc-include href=/tk/lib/components/w/html/parts/panel.part.html></wc-include>";
	}

        wc.groupEnd();
        return temp;
    };

    /**
     * @private
     * @_attributes
     */
    _attributes() {
        wc.group("Panel._attributes");
	
	if (0) {
	    // TRANSFER ALL ATTRIBUTES NOW (BELOW IS AN EXAMPLE)
	    // -------------------------------------------------
	    // SAMPLE CODE BELOW
 	    for (var key in this.propertiesW) {
		// SKIP CLASS AND ID
		if (key != "class" && key != "id") {
		    wc.log(key, this.properties[key]);

		    this.removeAttribute(key);
		    this.setAttribute(key, this.properties[key]);
		}
	    }	
	}
	
        wc.groupEnd();
    };

    /**
     * @private
     * @_render
     */
    _render() {
        wc.group("Panel._render");
	
	this.innerHTML = this._template();

        wc.groupEnd();
    };

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

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

	let obs = Panel.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("Panel._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("Panel._fetchAttributes");
	
	this.properties = {
	    uparam	: "",
	    cname	: "Panel",
	    author	: "Mel M. Heravi, Ph.D.",
	    version	: "1.0"
	};
	
	// SAVE WIDGET SPECIFIC PROPERTIES
	this.propertiesW = [];
	
	// GET ALL COMPONENT PROPERTIES
	let attrs = wc.getAttributes(this)
	
	// SAVE IN properties & propertiesW
 	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("Panel.configure: data=", data);

	// START TIME
	let time1 = Date.now();

	// IF JSON VARIABLE (data) IS PROVIDED
	if (data) {
	    // DIRECT CALL TO ACTION
	    this._process(data);
	} else {
	    // USUALLY TO INITIALIZE THE COMPONENT FROM A JSON URL
	    let self = this;

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

	// END TIME
	let time2 = Date.now();

	wc.groupEnd();
	return "T:" + (time2-time2);
    };

    /**
     * _process the instance object and artifacts
     * @private
     * @_process
     * MELIFIED
     */
    _process(data) {
	wc.group("Panel._process:", data);
	
	let template = $("#panel-template").html();
	
	// BASIC ASSUMPTIONS
	this.isOpen = true;
	this.collapsable = data.collapsable || false;

	// WE DO EXPECT AT LEAST THE BODY
	data.header = data.header || null;
	data.footer = data.footer || null;
	
	template = template.replace(/%HEADER%/, data.header);
	template = template.replace(/%FOOTER%/, data.footer);
	template = template.replace(/%BODY%/,     data.body);

	// ADD TEMPLATE TO PANEL CONTAINER
	$(this).empty().append(template);

	// SAVE THESE FOR USE LATER
	this.pbody   = $(this).find(".wc-panel-body");
	this.pheader = $(this).find(".wc-panel-header");
	this.pfooter = $(this).find(".wc-panel-footer");

	// IF COLLAPSABLE ADD CARET ICONS
	if (this.collapsable == true) {
	    this.pheader
		.append("<i class='fa fa-angle-up'></i>")
		.append("<i class='fa fa-angle-down'></i>")
		.css("cursor", "pointer");
	    
	}

	// SET PANEL HEIGHT
	this.pbody.height(this.properties.height || "300px");

	// HIDE FOOTER | FOOTER IF NOT IN JSON
	if (!data.footer) this.pfooter.hide();
	if (!data.header) this.pheader.hide();

	// PUBLISH ALL EVENTS OF INTEREST
	this._publish();

	wc.groupEnd();
    };

    /**
     * Initialize component
     * @_open
     * MELIFIED
     */
    _open() {
	wc.group("Panel._open:", this.id);

	if (this.isOpen) {
	    return;
	} else {
	    $(this).find(".wc-panel-header").click();
	}

	wc.groupEnd();
    };

    /**
     * Initialize component
     * @_close
     * MELIFIED
     */
    _close() {
	wc.group("Panel._close:", this.id);

	if (this.isClose) {
	    return;
	} else {
	    $(this).find(".wc-panel-header").click();
	}

	wc.groupEnd();
    };

    /**
     * Initialize component
     * @private
     * @_initialize
     */
    _initialize() {
	wc.group("Panel._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("Panel._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("Panel.disconnectedCallback")

        wc.groupEnd();
    };

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

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

	wc.groupEnd();
    };

    /**
     * @private
     * @_publish
     * MELIFIED
     */
    _publish() {
	wc.group("Panel._publish");

	let header = $(this).find(".wc-panel-header");

	if (this.collapsable == true) {
	    // PUBLISH CLICK EVENTS
	    $(this).find(".wc-panel-header").on("click", () => {
		let fa = $(this).find(".fa");
		
		if (this.isOpen) {
		    this.isOpen = false;
		} else {
		    this.isOpen = true;
		}

		$(fa).toggle();
		$(this.pbody).slideToggle();

		wc.publish("wc-panel", {
		    id: self.id,
		    time: new Date().getTime(),
		    action: "click",
		    status: this.isOpen
		});
	    });
	}
	
	wc.groupEnd();
	return true;
    };

    /**
     * Subscribe all to events of interest
     * @private
     * @_subscribe
     * MELIFIED
     */
    _subscribe() {
	wc.group("Panel._subscribe:", this.id);
	
	let self = this;

	// SUBSCRIPTION START
	wc.subscribe("wc-panel", function(msg,data) {
	    if (data.id == self.id) {
		wc.info(`SUBSCRIPTION TRIGGERED ${JSON.stringify(data)}`)
		switch(data.action) 
		{
		    case "toggle":
		    $(self).find(".wc-panel-header").click();
		    break;

		    case "open":
		    self._open();
		    break;

		    case "close":
		    self._close();
		    break;

		    default:
		    break;
		}
	    }
	});
	// SUBSCRIPTION END
	
	wc.groupEnd();
    }

    /**
     * FOR TESTING THE COMPONENT
     * @test
     * MELIFIED
     */
    test() {
	console.group("test.panel");

	// LIST OF COMMANDS FROM Panel.test
	var tests = [
	    {action:"close",            value:{}},
	    {action:"open",             value:{}},
	    {action:"toggle",           value:{}},
	    {action:"open",             value:{}},
	]

	for (var i = 0; i < tests.length; i++) {
	    wc.tester("wc-panel", "my-panel", tests[i], (i+1)*2000)
	}

	console.groupEnd();
    };
}

window.customElements.define('wc-panel', Panel);