Source: autocomplete.js

/**
 * Autocomplete Component<BR>
 * <BR><BR><img src=/tk/lib/components/w/img/autocomplete.png width=30% style="border:1px lime dashed;padding:20px">
 * <BR><BR><a href="/tk/lib/components/w/html/autocomplete.html">DEMO</a>
 */
class Autocomplete extends HTMLElement {
    constructor() {
        wc.group("Autocomplete.constructor")
	
        super();
        wc.groupEnd();
    };
    
    /**
     * Set observable values here. When Changed, attributeChangedCallback is invoked
     * @observedAttributes
     */
    static get observedAttributes() {
        wc.group("Autocomplete.observedAttributes");
	this.observables = [];
        wc.groupEnd();
        return this.observables;
    };
    /**
     * Initial Markup
     * @private
     * @_template
     */
    _template() {
        wc.group("Autocomplete.template");
	
	var temp = this.dom.content;
        wc.groupEnd();
        return temp;
    };
    /**
     * Called when this is attached to DOM
     * @connectedCallback. 
     */
    connectedCallback() {
        wc.group("Autocomplete.connectedCallback")
	
	let self = this;
	// GET PROPERTIES AND INTERESTING ELEMENTS
	this._initialize();
	// ADD COMPONENT MARKTOP
	this.innerHTML = `<input class="form-control form-control-lg" autofocus type="text" name="q" placeholder="ready ...">`
	this.cache = {};
        var demo1 = new autoComplete({
            selector: 'input[name="q"]',
            minChars: 1,
            source: function(term, response){
		// EMPTY CACHE
		self.cache = {};
                $.getJSON(self.properties.url, {q:term}, function (data) {
		    let d = [];
		    for (var i = 0; i < data.length; i++) {
			self.cache[data[i].short] = data[i];
			
                        d.push(data[i].long);
		    }
		    let input = self.querySelector("input");
		    
		    // if(d.length == 0) {
		    // 	wc.log(">>>>>>>>>", d.length);
		    // 	$(input).css({
		    // 	    "border-color":"red",
		    // 	    "color": "red"
		    // 	})
			
		    // 	wc.timeout(function(){
		    // 	$(input).css({
		    // 	    "border-color":"steelblue",
		    // 	    "color": "steelblue"
		    // 	})
		    // 	}, 2000);
		    // }
		    response(d);
                }).fail(function(jqxhr, textStatus, error){
                    var err = textStatus + ', ' + error;
                    alert("REQUEST FAILED: more info in developer console " + err);
                });
            },
	    onSelect: function(e, term, item){
		self._publish($(item).text());
	    }
        });
	
	// ADD STATS AND OTHER FINAL STUFF
	this._finalize();
        wc.groupEnd();
    };
    /**
     * Publish all events of interest
     * @private
     * @_publish
     */
    _publish(name) {
	wc.group("Autocomplete.publish:", name);
	wc.publish("wc-autocomplete", {
	    time: new Date().getTime(),
	    action: "selected",
	    uparam: this.cache[name]
	});
	
	wc.groupEnd();
    }
    /**
     * Called with .setAttribute(...) function call
     * @attributeChangedCallback
     */
    attributeChangedCallback(attr, oldval, newval) {
        wc.group("Autocomplete.attributeChangedCallback:", attr, oldval, newval);
	this.properties = this.properties || [];
	let obs = Autocomplete.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":
		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("Autocomplete._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("Autocomplete._fetchAttributes");
	
	this.properties = {
	    cname      : "Autocomplete",
	    author     : "Mel M. Heravi",
	    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
     */
    configure(aname) {
	wc.group("Autocomplete.configure:", aname);
	// IF JSON VARIABLE (aname) IS PROVIDED
	if (aname) {
	    this._process(aname);
	} 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("Autocomplete._process:", data);
	
	// DO WHATEVER WITH THE DATA
	
	wc.groupEnd();
    };
    /**
     * Initialize component
     * @private
     * @_initialize
     */
    _initialize() {
	wc.group("Autocomplete._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("Autocomplete._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("Autocomplete.disconnectedCallback")
	// FREE MEMORY AND CLEANUP
        wc.groupEnd();
    };
}
window.customElements.define('wc-autocomplete', Autocomplete);