💥 customElement (#11)

* 🎉

* Update customElement.js

* 💥 `observedAttributes`

docs/p04-observables.html

@@ -121,7 +121,7 @@ document.head.append(
 const interval= 5 * 1000;
 setTimeout(clearInterval, 10*interval,
 	setInterval(()=> count(count()+1), interval));
-</code></div><script>Flems(document.getElementById("code-example-1-ehcq40v0h5k"), JSON.parse("{\"files\":[{\"name\":\".js\",\"content\":\"import { O } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\nconst count= O(0);\\n\\nimport { el } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\ndocument.body.append(\\n\\tel(\\\"p\\\", O(()=> \\\"Currently: \\\"+count())),\\n\\tel(\\\"p\\\", { classList: { red: O(()=> count()%2) }, dataset: { count }, textContent: \\\"Attributes example\\\" })\\n);\\ndocument.head.append(\\n\\tel(\\\"style\\\", \\\".red { color: red; }\\\")\\n);\\n\\nconst interval= 5 * 1000;\\nsetTimeout(clearInterval, 10*interval,\\n\\tsetInterval(()=> count(count()+1), interval));\\n\"}],\"toolbar\":false}"));</script><p>To derived attribute based on value of observable variable just use the observable as a&nbsp;value of the attribute (<code>assign(element, { attribute: O('value') })</code>). <code>assign</code>/<code>el</code> provides ways to glue reactive attributes/classes more granularly into the DOM. Just use dedicated build-in attributes <code>dataset</code>, <code>ariaset</code> and <code>classList</code>.</p><p>For computation, you can use the derived observable (see above) like <code>assign(element, { textContent: O(()=&gt; 'Hello '+WorldObservable()) })</code>.</p><p>To represent part of the template filled dynamically based on the observable value use <code>O.el(observable, DOMgenerator)</code>. This was already used in the todo example above or see:</p><!--<dde:mark type="component" name="example" host="this" ssr/>--><div id="code-example-2-8r8qappf8mo" class="example"><!--<dde:mark type="component" name="code" host="parentElement" ssr/>--><code class="language-js">import { O } from "https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js";
+</code></div><script>Flems(document.getElementById("code-example-1-ehcq40v0h5k"), JSON.parse("{\"files\":[{\"name\":\".js\",\"content\":\"import { O } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\nconst count= O(0);\\n\\nimport { el } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\ndocument.body.append(\\n\\tel(\\\"p\\\", O(()=> \\\"Currently: \\\"+count())),\\n\\tel(\\\"p\\\", { classList: { red: O(()=> count()%2) }, dataset: { count }, textContent: \\\"Attributes example\\\" })\\n);\\ndocument.head.append(\\n\\tel(\\\"style\\\", \\\".red { color: red; }\\\")\\n);\\n\\nconst interval= 5 * 1000;\\nsetTimeout(clearInterval, 10*interval,\\n\\tsetInterval(()=> count(count()+1), interval));\\n\"}],\"toolbar\":false}"));</script><p>To derived attribute based on value of observable variable just use the observable as a&nbsp;value of the attribute (<code>assign(element, { attribute: O('value') })</code>). <code>assign</code>/<code>el</code> provides ways to glue reactive attributes/classes more granularly into the DOM. Just use dedicated build-in attributes <code>dataset</code>, <code>ariaset</code> and <code>classList</code>.</p><p>For computation, you can use the “derived observable” (see above) like <code>assign(element, { textContent: O(()=&gt; 'Hello '+WorldObservable()) })</code>. This is read-only observable its value is computed based on given function and updated when any observable used in the function changes.</p><p>To represent part of the template filled dynamically based on the observable value use <code>O.el(observable, DOMgenerator)</code>. This was already used in the todo example above or see:</p><!--<dde:mark type="component" name="example" host="this" ssr/>--><div id="code-example-2-8r8qappf8mo" class="example"><!--<dde:mark type="component" name="code" host="parentElement" ssr/>--><code class="language-js">import { O } from "https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js";
 const count= O(0, {
 	add(){ this.value= this.value + Math.round(Math.random()*10); }
 });
@@ -147,4 +147,4 @@ setTimeout(clearInterval, 10*interval, setInterval(function(){
 	O.action(count, "add");
 	O.action(numbers, "push", count());
 }, interval));
-</code></div><script>Flems(document.getElementById("code-example-2-8r8qappf8mo"), JSON.parse("{\"files\":[{\"name\":\".js\",\"content\":\"import { O } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\nconst count= O(0, {\\n\\tadd(){ this.value= this.value + Math.round(Math.random()*10); }\\n});\\nconst numbers= O([ count() ], {\\n\\tpush(next){ this.value.push(next); }\\n});\\n\\nimport { el } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\ndocument.body.append(\\n\\tO.el(count, count=> count%2\\n\\t\\t? el(\\\"p\\\", \\\"Last number is odd.\\\")\\n\\t\\t: el()\\n\\t),\\n\\tel(\\\"p\\\", \\\"Lucky numbers:\\\"),\\n\\tel(\\\"ul\\\").append(\\n\\t\\tO.el(numbers, numbers=> numbers.toReversed()\\n\\t\\t\\t.map(n=> el(\\\"li\\\", n)))\\n\\t)\\n);\\n\\nconst interval= 5*1000;\\nsetTimeout(clearInterval, 10*interval, setInterval(function(){\\n\\tO.action(count, \\\"add\\\");\\n\\tO.action(numbers, \\\"push\\\", count());\\n}, interval));\\n\"}],\"toolbar\":false}"));</script><div class="notice"><!--<dde:mark type="component" name="mnemonic" host="parentElement" ssr/>--><h3 id="h-mnemonic"><!--<dde:mark type="component" name="h3" host="parentElement" ssr/>--><a href="#h-mnemonic" tabindex="-1">#</a> Mnemonic</h3><ul><li><code>O(&lt;value&gt;)</code> — observable: reactive value</li><li><code>O(()=&gt; &lt;computation&gt;)</code> — observable: reactive value dependent on calculation using other observables</li><li><code>O.on(&lt;observable&gt;, &lt;listener&gt;[, &lt;options&gt;])</code> — listen to the observable value changes</li><li><code>O.clear(...&lt;observables&gt;)</code> — off and clear observables</li><li><code>O(&lt;value&gt;, &lt;actions&gt;)</code> — observable: pattern to create complex reactive objects/arrays</li><li><code>O.action(&lt;observable&gt;, &lt;action-name&gt;, ...&lt;action-arguments&gt;)</code> — invoke an&nbsp;action for given observable</li><li><code>O.el(&lt;observable&gt;, &lt;function-returning-dom&gt;)</code> — render partial dom structure (template) based on the current observable value</li></ul></div><div class="prevNext"><!--<dde:mark type="component" name="prevNext" host="parentElement" ssr/>--><a rel="prev" href="p03-events" title="Using not only events in UI declaratively."><!--<dde:mark type="component" name="pageLink" host="parentElement" ssr/>-->Events and Addons (previous)</a><a rel="next" href="p05-scopes" title="Organizing UI into components"><!--<dde:mark type="component" name="pageLink" host="parentElement" ssr/>-->(next) Scopes and components</a></div></main></body></html>
+</code></div><script>Flems(document.getElementById("code-example-2-8r8qappf8mo"), JSON.parse("{\"files\":[{\"name\":\".js\",\"content\":\"import { O } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\nconst count= O(0, {\\n\\tadd(){ this.value= this.value + Math.round(Math.random()*10); }\\n});\\nconst numbers= O([ count() ], {\\n\\tpush(next){ this.value.push(next); }\\n});\\n\\nimport { el } from \\\"https://cdn.jsdelivr.net/gh/jaandrle/deka-dom-el/dist/esm-with-observables.js\\\";\\ndocument.body.append(\\n\\tO.el(count, count=> count%2\\n\\t\\t? el(\\\"p\\\", \\\"Last number is odd.\\\")\\n\\t\\t: el()\\n\\t),\\n\\tel(\\\"p\\\", \\\"Lucky numbers:\\\"),\\n\\tel(\\\"ul\\\").append(\\n\\t\\tO.el(numbers, numbers=> numbers.toReversed()\\n\\t\\t\\t.map(n=> el(\\\"li\\\", n)))\\n\\t)\\n);\\n\\nconst interval= 5*1000;\\nsetTimeout(clearInterval, 10*interval, setInterval(function(){\\n\\tO.action(count, \\\"add\\\");\\n\\tO.action(numbers, \\\"push\\\", count());\\n}, interval));\\n\"}],\"toolbar\":false}"));</script><div class="notice"><!--<dde:mark type="component" name="mnemonic" host="parentElement" ssr/>--><h3 id="h-mnemonic"><!--<dde:mark type="component" name="h3" host="parentElement" ssr/>--><a href="#h-mnemonic" tabindex="-1">#</a> Mnemonic</h3><ul><li><code>O(&lt;value&gt;)</code> — observable: reactive value</li><li><code>O(()=&gt; &lt;computation&gt;)</code> — read-only observable: reactive value dependent on calculation using other observables</li><li><code>O.on(&lt;observable&gt;, &lt;listener&gt;[, &lt;options&gt;])</code> — listen to the observable value changes</li><li><code>O.clear(...&lt;observables&gt;)</code> — off and clear observables</li><li><code>O(&lt;value&gt;, &lt;actions&gt;)</code> — observable: pattern to create complex reactive objects/arrays</li><li><code>O.action(&lt;observable&gt;, &lt;action-name&gt;, ...&lt;action-arguments&gt;)</code> — invoke an&nbsp;action for given observable</li><li><code>O.el(&lt;observable&gt;, &lt;function-returning-dom&gt;)</code> — render partial dom structure (template) based on the current observable value</li></ul></div><div class="prevNext"><!--<dde:mark type="component" name="prevNext" host="parentElement" ssr/>--><a rel="prev" href="p03-events" title="Using not only events in UI declaratively."><!--<dde:mark type="component" name="pageLink" host="parentElement" ssr/>-->Events and Addons (previous)</a><a rel="next" href="p05-scopes" title="Organizing UI into components"><!--<dde:mark type="component" name="pageLink" host="parentElement" ssr/>-->(next) Scopes and components</a></div></main></body></html>

docs_src/components/mnemonic/observables-init.js

@@ -7,7 +7,7 @@ export function mnemonic(){
 			el("code", "O(<value>)"), " — observable: reactive value",
 		),
 		el("li").append(
-			el("code", "O(()=> <computation>)"), " — observable: reactive value dependent on calculation using other observables",
+			el("code", "O(()=> <computation>)"), " — read-only observable: reactive value dependent on calculation using other observables",
 		),
 		el("li").append(
 			el("code", "O.on(<observable>, <listener>[, <options>])"), " — listen to the observable value changes",

docs_src/p04-observables.html.js

@@ -88,7 +88,9 @@ export function page({ pkg, info }){
 			el("code", "ariaset"), " and ", el("code", "classList"), "."
 		),
 		el("p").append(
-			"For computation, you can use the derived observable (see above) like ", el("code", "assign(element, { textContent: O(()=> 'Hello '+WorldObservable()) })"), "."
+			"For computation, you can use the “derived observable” (see above) like ", el("code", "assign(element, { textContent: O(()=> 'Hello '+WorldObservable()) })"), ".",
+			" ",
+			"This is read-only observable its value is computed based on given function and updated when any observable used in the function changes."
 		),
 		el("p").append(
 			"To represent part of the template filled dynamically based on the observable value use ", el("code", "O.el(observable, DOMgenerator)"), ".",

examples/components/3rd-party.js

@@ -1,4 +1,4 @@
-import { style, el, O } from '../exports.js';
+import { style, el, O, isObservable } from '../exports.js';
 const className= style.host(thirdParty).css`
 	:host {
 		color: green;
@@ -22,12 +22,13 @@ export function thirdParty(){
 	// Array.from((new URL(location)).searchParams.entries())
 	// 	.forEach(([ key, value ])=> O.action(store, "set", key, value));
 	// O.on(store, data=> history.replaceState("", "", "?"+(new URLSearchParams(JSON.parse(JSON.stringify(data)))).toString()));
-	useAdapter(store, store_adapter, {
+	useStore(store_adapter, {
 		onread(data){
 			Array.from(data.entries())
 				.forEach(([ key, value ])=> O.action(store, "set", key, value));
+			return store;
 		}
-	});
+	})();
 	return el("input", {
 		className,
 		value: store().value(),
@@ -36,9 +37,14 @@ export function thirdParty(){
 	});
 }
 
-function useAdapter(observable, adapter, { onread, onbeforewrite }= {}){
+function useStore(adapter_in, { onread, onbeforewrite }= {}){
-	if(!onread) onread= observable;
+	const adapter= typeof adapter_in === "function" ? { read: adapter_in } : adapter_in;
+	if(!onread) onread= O;
 	if(!onbeforewrite) onbeforewrite= data=> JSON.parse(JSON.stringify(data));
-	onread(adapter.read()); //TODO OK as synchronous
+	return function useStoreInner(data_read){
+		const observable= onread(adapter.read(data_read)); //TODO OK as synchronous
+		if(adapter.write && isObservable(observable))
 			O.on(observable, data=> adapter.write(onbeforewrite(data)));
+		return observable;
+	};
 }

examples/components/webComponent.js

@@ -13,24 +13,29 @@ export class CustomHTMLTestElement extends HTMLElement{
 	connectedCallback(){
 		if(!this.hasAttribute("pre-name")) this.setAttribute("pre-name", "default");
 		this.attachShadow({ mode: "open" }).append(
-			customElementRender(this, this.render)
+			customElementRender(this, this.render, this.attributes)
 		);
 	}
 
-	render({ test }){
+	attributes(element){
+		const observed= O.observedAttributes(element);
+		return Object.assign({ test: element.test }, observed);
+	}
+	render({ name, preName, test }){
 		console.log(scope.state);
 		scope.host(
 			on.connected(()=> console.log(CustomHTMLTestElement)),
 			on.attributeChanged(e=> console.log(e)),
 			on.disconnected(()=> console.log(CustomHTMLTestElement))
 		);
-		const name= O.attribute("name");
+		const text= text=> el().append(
-		const preName= O.attribute("pre-name");
+			el("#text", text),
-		
+			" | "
-		console.log({ name, test, preName});
+		);
 		return el("p").append(
-			el("#text", name),
+			text(test),
-			el("#text", preName),
+			text(name),
+			text(preName),
 			el("button", { type: "button", textContent: "pre-name", onclick: ()=> preName("Ahoj") })
 		);
 	}

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "deka-dom-el",
-	"version": "0.7.5",
+	"version": "0.7.6",
 	"description": "A low-code library that simplifies the creation of native DOM elements/components using small wrappers and tweaks.",
 	"author": "Jan Andrle <andrle.jan@centrum.cz>",
 	"license": "MIT",
@@ -46,6 +46,7 @@
 		"browser": true,
 		"undef": "true",
 		"latedef": "true",
+		"-W014": true,
 		"maxparams": 5,
 		"maxdepth": 3,
 		"maxcomplexity": 14,
@@ -58,7 +59,7 @@
 	"size-limit": [
 		{
 			"path": "./index.js",
-			"limit": "9.75 kB",
+			"limit": "9.85 kB",
 			"gzip": false,
 			"brotli": false
 

src/customElement.js

@@ -1,10 +1,11 @@
 import { scope } from "./dom.js";
-export function customElementRender(custom_element, render, props= custom_element){
+export function customElementRender(custom_element, render, props= observedAttributes){
 	scope.push({
 		scope: custom_element,
 		host: (...c)=> c.length ? c.forEach(c=> c(custom_element)) : custom_element,
 		custom_element
 	});
+	if(typeof props==="function") props= props.call(custom_element, custom_element);
 	const out= render.call(custom_element, props);
 	scope.pop();
 	return out;
@@ -31,3 +32,8 @@ export { lifecycleToEvents as customElementWithDDE };
 function wrapMethod(obj, method, apply){
 	obj[method]= new Proxy(obj[method] || (()=> {}), { apply });
 }
+
+import { observedAttributes as oA } from "./helpers.js";
+export function observedAttributes(instance){
+	return oA(instance, (i, n)=> i.getAttribute(n));
+}

src/events.js

@@ -84,6 +84,7 @@ on.attributeChanged= function(listener, options){
 		});
 		const c= onAbort(options.signal, ()=> observer.disconnect());
 		if(c) observer.observe(element, { attributes: true });
+		//TODO: clean up when element disconnected
 		return element;
 	};
 };

src/helpers.js

@@ -15,3 +15,12 @@ export function onAbort(signal, listener){
 		signal.removeEventListener("abort", listener);
 	};
 }
+export function observedAttributes(instance, observedAttribute){
+	const { observedAttributes= [] }= instance.constructor;
+	return observedAttributes
+		.reduce(function(out, name){
+			Reflect.set(out, kebabToCamel(name), observedAttribute(instance, name));
+			return out;
+		}, {});
+}
+function kebabToCamel(name){ return name.replace(/-./g, x=> x[1].toUpperCase()); }

src/observables-lib.js

@@ -9,7 +9,7 @@ const stack_watch= [];
 /**
  * ### `WeakMap<function, Set<ddeObservable<any, any>>>`
  * The `Set` is in the form of `[ source, ...depended observables (DSs) ]`.
- * When the DS is cleaned (`S.clear`) it is removed from DSs,
+ * When the DS is cleaned (`O.clear`) it is removed from DSs,
  * if remains only one (`source`) it is cleared too.
  * ### `WeakMap<object, function>`
  * This is used for revesed deps, the `function` is also key for `deps`.
@@ -18,16 +18,16 @@ const stack_watch= [];
 const deps= new WeakMap();
 export function observable(value, actions){
 	if(typeof value!=="function")
-		return create(value, actions);
+		return create(false, value, actions);
 	if(isObservable(value)) return value;
 	
-	const out= create();
+	const out= create(true);
 	const contextReWatch= function(){
 		const [ origin, ...deps_old ]= deps.get(contextReWatch);
 		deps.set(contextReWatch, new Set([ origin ]));
 
 		stack_watch.push(contextReWatch);
-		out(value());
+		write(out, value());
 		stack_watch.pop();
 
 		if(!deps_old.length) return;
@@ -113,41 +113,38 @@ observable.el= function(o, map){
 	return out;
 };
 import { on } from "./events.js";
+import { observedAttributes } from "./helpers.js";
+function observedAttribute(instance, name){
+	const out= (...args)=> !args.length
+		? instance.getAttribute(name)
+		: instance.setAttribute(name, ...args);
+	out.attribute= name;
+	return out;
+}
 const key_attributes= "__dde_attributes";
-observable.attribute= function(name, initial= null){
+observable.observedAttributes= function(element){
-	//TODO host=element & reuse existing
+	const attrs= observedAttributes(element, observedAttribute);
-	const out= observable(initial);
+	const store= element[key_attributes]= {};
-	let element;
+	const actions= {
-	scope.host(el=> {
+		_set(value){ this.value= value; },
-		element= el;
+	};
-		if(elementAttribute(element, "has", name)) out(elementAttribute(element, "get", name));
+	Object.keys(attrs).forEach(name=> {
-		else if(initial!==null) elementAttribute(element, "set", name, initial);
+		const attr= attrs[name]= toObservable(attrs[name], attrs[name](), actions);
-		
+		store[attr.attribute]= attr;
-		if(el[key_attributes]){
+	});
-			el[key_attributes][name]= out;
-			return;
-		}
-		element[key_attributes]= { [name]: out };
 	on.attributeChanged(function attributeChangeToObservable({ detail }){
-			/*! This maps attributes to observables (`S.attribute`).
+		/*! This maps attributes to observables (`O.observedAttributes`).
 			* Investigate `__dde_attributes` key of the element.*/
 		const [ name, value ]= detail;
 		const curr= element[key_attributes][name];
-			if(curr) return curr(value);
+		if(curr) return observable.action(curr, "_set", value);
 	})(element);
 	on.disconnected(function(){
-			/*! This removes all observables mapped to attributes (`S.attribute`).
+		/*! This removes all observables mapped to attributes (`O.observedAttributes`).
 			* Investigate `__dde_attributes` key of the element.*/
 		observable.clear(...Object.values(element[key_attributes]));
 	})(element);
-	});
+	return attrs;
-	return new Proxy(out, {
-		apply(target, _, args){
-			if(!args.length) return target();
-			const value= args[0];
-			return elementAttribute(element, "set", name, value);
-		}
-	});
 };
 
 import { typeOf } from './helpers.js';
@@ -169,7 +166,7 @@ function removeObservablesFromElements(o, listener, ...notes){
 			element[key_reactive]= [];
 			on.disconnected(()=>
 				/*!
-				 * Clears all Observables listeners added in the current scope/host (`S.el`, `assign`, …?).
+				 * Clears all Observables listeners added in the current scope/host (`O.el`, `assign`, …?).
 				 * You can investigate the `__dde_reactive` key of the element.
 				 * */
 				element[key_reactive].forEach(([ [ o, listener ] ])=>
@@ -180,9 +177,10 @@ function removeObservablesFromElements(o, listener, ...notes){
 	});
 }
 
-function create(value, actions){
+function create(is_readonly, value, actions){
-	const o=  (...value)=>
+	const o= is_readonly
-		value.length ? write(o, ...value) : read(o);
+		? ()=> read(o)
+		: (...value)=> value.length ? write(o, ...value) : read(o);
 	return toObservable(o, value, actions);
 }
 const protoSigal= Object.assign(Object.create(null), {