Source: blockui.js

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

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

	this.observables = [];

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

    /**
     * Called when this is attached to DOM
     * @connectedCallback. 
     */
    connectedCallback() {
        wc.group("Blockui.connectedCallback")
	
	// 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 = "<img id='wc-img-loading' src='/tk/img/common/spinner.gif' style='display:none' width=80>";
	    
	// ADD STATS AND OTHER FINAL STUFF
	this._finalize();

        wc.groupEnd();
    };

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

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

	let obs = Blockui.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("Blockui._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("Blockui._fetchAttributes");
	
	this.properties = {
	    uparam	: "",
	    cname	: "Blockui",
	    author	: "Mel M. Heravi",
	    version	: "1.0",
	    background	: "#CCC",
	    parent	: "body"
	};
	
	// 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("Blockui.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("Blockui._process:", data);
	
	// DO WHATEVER WITH THE DATA
	
	wc.groupEnd();
    };

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

	// FREE MEMORY AND CLEANUP

        wc.groupEnd();
    };

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

    /**
     * @show
     */
    show() {
	wc.group("Blockui.show");

	if (this.properties.parent == "body") {
	    $.blockUI({ 
		cursorReset: 'default',
		cursor: null,
		message: $("#wc-img-loading"),
		overlayCSS: {
		    backgroundColor: this.properties.background,
		    cursor: "not-allowed",
		},
		css: { 
		    background: "transparent",
		    border: 0,
                    top:  ($(window).height() - 80) /2 + 'px', 
                    left: ($(window).width() - 500) /2 + 'px', 
                    width: '400px',
		    cursor: "not-allowed",
		} 
            }); 
	} else {
	    $(this.properties.parent).block({ 
		message: $("#wc-img-loading"),
		overlayCSS: {
		    backgroundColor: this.properties.background,
		    cursor: "not-allowed",
		},
		css: { 
		    background: "transparent",
		    border: 0,
                    top:  ($(this.properties.parent).height() - 80) /2 + 'px', 
                    left: ($(this.properties.parent).width() - 500) /2 + 'px', 
                    width: '400px',
		    cursor: "not-allowed",
		} 
            }); 
	} 
	wc.groupEnd();
    };

    /**
     * @hide
     */
    hide() {
	wc.group("Blockui.show");

	if (this.properties.parent == "body") {
	    $.unblockUI();
	} else {
	    $(this.properties.parent).unblock();
	}
 
	wc.groupEnd();
    };
}

window.customElements.define('wc-blockui', Blockui);