🔤

docs/components/examples/signals/derived.js

@@ -0,0 +1,13 @@
+import { S } from "deka-dom-el/signals";
+
+// Create base signals
+const firstName = S("John");
+const lastName = S("Doe");
+
+// Create a derived signal
+const fullName = S(() => firstName.get() + " " + lastName.get());
+
+// The fullName signal updates automatically when either dependency changes
+S.on(fullName, name => console.log("Name changed to:", name));
+
+firstName.set("Jane"); // logs: "Name changed to: Jane Doe"

docs/p04-signals.html.js

@@ -1,6 +1,6 @@
 import { T, t } from "./utils/index.js";
 export const info= {
-	title: t`Signals and reactivity`,
+	title: t`Signals and Reactivity`,
 	description: t`Managing reactive UI state with signals.`,
 };
 
@@ -43,87 +43,243 @@ const references= {
 export function page({ pkg, info }){
 	const page_id= info.id;
 	return el(simplePage, { info, pkg }).append(
-		el("h2", t`Using signals to manage reactivity`),
+		el("h2", t`Building Reactive UIs with Signals`),
 		el("p").append(...T`
-			How a program responds to variable data or user interactions is one of the fundamental problems of
+			Signals provide a simple yet powerful way to create reactive applications with DDE. They handle the
-			programming. If we desire to solve the issue in a declarative manner, signals may be a viable approach.
+			fundamental challenge of keeping your UI in sync with changing data in a declarative, efficient way.
 		`),
+		el("div", { class: "dde-callout" }).append(
+			el("h4", t`What Makes Signals Special?`),
+			el("ul").append(
+				el("li", t`Fine-grained reactivity without complex state management`),
+				el("li", t`Automatic UI updates when data changes`),
+				el("li", t`Clean separation between data, logic, and UI`),
+				el("li", t`Small runtime with minimal overhead`),
+				el("li", t`Works seamlessly with DDE's DOM creation`),
+				el("li", t`No dependencies or framework lock-in`)
+			)
+		),
 		el(code, { src: fileURL("./components/examples/signals/intro.js"), page_id }),
 
-		el(h3, t`Introducing signals`),
+		el(h3, t`The 3-Part Structure of Signals`),
 		el("p").append(...T`
-			Let’s re-introduce
+			Signals organize your code into three distinct parts, following the
-			${el("a", { textContent: t`3PS principle`, href: "./#h-event-driven-programming--parts-separation--ps" })}.
+			${el("a", { textContent: t`3PS principle`, href: "./#h-event-driven-programming--parts-separation--ps" })}:
-		`),
-		el("p").append(...T`
-			Using signals, we split program logic into the three parts. Firstly (α), we create a variable (constant)
-			representing reactive value. Somewhere later, we can register (β) a logic reacting to the signal value
-			changes. Similarly, in a remaining part (γ), we can update the signal value.
 		`),
+		el("div", { class: "dde-signal-diagram" }).append(
+			el("div", { class: "signal-part" }).append(
+				el("h4", t`α: Create Signal`),
+				el(code, { content: "const count = S(0);", page_id }),
+				el("p", t`Define a reactive value that can be observed and changed`)
+			),
+			el("div", { class: "signal-part" }).append(
+				el("h4", t`β: React to Changes`),
+				el(code, { content: "S.on(count, value => updateUI(value));", page_id }),
+				el("p", t`Subscribe to signal changes with callbacks or effects`)
+			),
+			el("div", { class: "signal-part" }).append(
+				el("h4", t`γ: Update Signal`),
+				el(code, { content: "count.set(count.get() + 1);", page_id }),
+				el("p", t`Modify the signal value, which automatically triggers updates`)
+			)
+		),
 		el(example, { src: fileURL("./components/examples/signals/signals.js"), page_id }),
+
+		el("div", { class: "dde-note" }).append(
+			el("p").append(...T`
+				Signals implement the ${el("a", { textContent: t`Publish–subscribe pattern`, ...references.wiki_pubsub })},
+				a form of ${el("a", { textContent: t`Event-driven programming`, ...references.wiki_event_driven })}.
+				This architecture allows different parts of your application to stay synchronized through a shared signal,
+				without direct dependencies on each other.
+			`)
+		),
+
+		el(h3, t`Signal Essentials: Core API`),
+		el("div", { class: "dde-function-table" }).append(
+			el("dl").append(
+				el("dt", t`Creating a Signal`),
+				el("dd", t`S(initialValue) → creates a signal with the given value`),
+
+				el("dt", t`Reading a Signal`),
+				el("dd", t`signal.get() → returns the current value`),
+
+				el("dt", t`Writing to a Signal`),
+				el("dd", t`signal.set(newValue) → updates the value and notifies subscribers`),
+
+				el("dt", t`Subscribing to Changes`),
+				el("dd", t`S.on(signal, callback) → runs callback whenever signal changes`),
+
+				el("dt", t`Unsubscribing`),
+				el("dd", t`S.on(signal, callback, { signal: abortController.signal })`)
+			)
+		),
 		el("p").append(...T`
-			All this is just an example of
+			Signals can be created with any type of value, but they work best with
-			${el("a", { textContent: t`Event-driven programming`, ...references.wiki_event_driven })} and
+			${el("a", { textContent: t`primitive types`, ...references.mdn_primitive })} like strings, numbers, and booleans.
-			${el("a", { textContent: t`Publish–subscribe pattern`, ...references.wiki_pubsub })} (compare for example
+			For complex data types like objects and arrays, you'll want to use Actions (covered below).
-			with ${el("a", { textContent: t`fpubsub library`, ...references.fpubsub })}). All three parts can be in
-			some manner independent and still connected to the same reactive entity.
 		`),
+
+		el(h3, t`Derived Signals: Computed Values`),
 		el("p").append(...T`
-			Signals are implemented in the library as objects with methods. To see current value of signal,
+			Computed values (also called derived signals) automatically update when their dependencies change.
-			call the get method ${el("code", "console.log(signal.get())")}. To update the signal value, use the set method
+			Create them by passing a function to S():
-			${el("code", `signal.set('${t`a new value`}')`)}. For listenning the signal value changes, use
-			${el("code", "S.on(signal, console.log)")}.
 		`),
+		el(example, { src: fileURL("./components/examples/signals/derived.js"), page_id }),
 		el("p").append(...T`
-			Similarly to the ${el("code", "on")} function to register DOM events listener. You can use
+			Derived signals are read-only - you can't call .set() on them. Their value is always computed
-			${el("code", "AbortController")}/${el("code", "AbortSignal")} to ${el("em", "off")}/stop listenning. In
+			from their dependencies. They're perfect for transforming or combining data from other signals.
-			example, you also found the way for representing “live” piece of code computation pattern (derived signal):
 		`),
 		el(example, { src: fileURL("./components/examples/signals/computations-abort.js"), page_id }),
 
-		el(h3, t`Signals and actions`),
+		el(h3, t`Signal Actions: For Complex State`),
 		el("p").append(...T`
-			${el("code", `S(/* ${t`primitive`} */)`)} allows you to declare simple reactive variables, typically, around
+			When working with objects, arrays, or other complex data structures, Signal Actions provide
-			${el("em", t`immutable`)} ${el("a", { textContent: t`primitive types`, ...references.mdn_primitive })}.
+			a structured way to modify state while maintaining reactivity.
-			However, it may also be necessary to use reactive arrays, objects, or other complex reactive structures.
 		`),
+		el("div", { class: "dde-illustration" }).append(
+			el("h4", t`Actions vs. Direct Mutation`),
+			el("div", { class: "comparison" }).append(
+				el("div", { class: "bad-practice" }).append(
+					el("h5", t`❌ Without Actions`),
+					el(code, { content: `
+const todos = S([]);
+// Directly mutating the array
+const items = todos.get();
+items.push("New todo");
+// This WON'T trigger updates!`, page_id }))
+				),
+				el("div", { class: "good-practice" }).append(
+					el("h5", t`✅ With Actions`),
+					el(code, { content: `const todos = S([], {
+	add(text) {
+		this.value.push(text);
+		// Subscribers notified automatically
+	}
+});
+
+// Use the action
+S.action(todos, "add", "New todo");`, page_id })
+				)
+		),
 		el(example, { src: fileURL("./components/examples/signals/actions-demo.js"), page_id }),
-		el("p", t`…but typical user-case is object/array (maps, sets and other mutable objects):`),
+
-		el(example, { src: fileURL("./components/examples/signals/actions-todos.js"), page_id }),
 		el("p").append(...T`
-			In some way, you can compare it with ${el("a", { textContent: "useReducer", ...references.mdn_use_reducer })}
+			Actions provide these benefits:
-			hook from React. So, the ${el("code", "S(<data>, <actions>)")} pattern creates a store “machine”. We can
+		`),
-			then invoke (dispatch) registered action by calling ${el("code", "S.action(<signal>, <name>, ...<args>)")}
+		el("ul").append(
-			after the action call the signal calls all its listeners. This can be stopped by calling
+			el("li", t`Encapsulate state change logic in named methods`),
-			${el("code", "this.stopPropagation()")} in the method representing the given action. As it can be seen in
+			el("li", t`Guarantee notifications when state changes`),
-			examples, the “store” value is available also in the function for given action (${el("code", "this.value")}).
+			el("li", t`Prevent accidental direct mutations`),
+			el("li", t`Act similar to reducers in other state management libraries`)
+		),
+		el("p").append(...T`
+			Here's a more complete example of a todo list using signal actions:
+		`),
+		el(example, { src: fileURL("./components/examples/signals/actions-todos.js"), page_id }),
+
+		el("div", { class: "dde-tip" }).append(
+			el("p").append(...T`
+				${el("strong", "Special Action Methods")}: Signal actions can implement special lifecycle hooks:
+			`),
+			el("ul").append(
+				el("li", t`[S.symbols.onclear]() - Called when the signal is cleared`),
+				el("li", t`[S.symbols.onget]() - Called when the signal value is read`),
+				el("li", t`[S.symbols.onset]() - Called after the signal value is changed`)
+			)
+		),
+
+		el(h3, t`Connecting Signals to the DOM`),
+		el("p").append(...T`
+			Signals really shine when connected to your UI. DDE provides several ways to bind signals to DOM elements:
 		`),
 
-		el(h3, t`Reactive DOM attributes and elements`),
+		el("div", { class: "dde-tabs" }).append(
-		el("p", t`There are two fundamental ways to make your DOM reactive with signals:`),
+			el("div", { class: "tab", "data-tab": "attributes" }).append(
-		el("ol").append(
+				el("h4", t`Reactive Attributes`),
-			el("li", t`Reactive attributes: Update properties, attributes, and styles of existing elements`),
+				el("p", t`Bind signal values directly to element attributes, properties, or styles:`),
-			el("li").append(...T`Reactive elements: Dynamically create or update DOM elements based on data changes
+				el(code, { content: `// Create a signal
-				(for conditions and loops)`)
+const color = S("blue");
+
+// Bind it to an element's style
+el("div", {
+	style: {
+		color, // Updates when signal changes
+		fontWeight: S(() => color.get() === "red" ? "bold" : "normal")
+	}
+}, "This text changes color");
+
+// Later:
+color.set("red"); // UI updates automatically`, page_id })
+			),
+			el("div", { class: "tab", "data-tab": "elements" }).append(
+				el("h4", t`Reactive Elements`),
+				el("p", t`Dynamically create or update elements based on signal values:`),
+				el(code, { content: `// Create an array signal
+const items = S(["Apple", "Banana", "Cherry"]);
+
+// Create a dynamic list that updates when items change
+el("ul").append(
+	S.el(items, items =>
+		items.map(item => el("li", item))
+	)
+);
+
+// Later:
+S.action(items, "push", "Dragonfruit"); // List updates automatically`, page_id })
+			)
 		),
+
 		el(example, { src: fileURL("./components/examples/signals/dom-attrs.js"), page_id }),
 		el("p").append(...T`
-			To derived attribute based on value of signal variable just use the signal as a value of the attribute
+			The ${el("code", "assign")} and ${el("code", "el")} functions detect signals automatically and handle binding.
-			(${el("code", "assign(element, { attribute: S('value') })")}). ${el("code", "assign")}/${el("code", "el")}
+			You can use special properties like ${el("code", "dataset")}, ${el("code", "ariaset")}, and
-			provides ways to glue reactive attributes/classes more granularly into the DOM. Just use dedicated build-in
+			${el("code", "classList")} for fine-grained control over specific attribute types.
-			attributes ${el("code", "dataset")}, ${el("code", "ariaset")} and ${el("code", "classList")}.
 		`),
+
 		el("p").append(...T`
-			For computation, you can use the “derived signal” (see above) like
+			${el("code", "S.el()")} is especially powerful for conditional rendering and lists:
-			${el("code", "assign(element, { textContent: S(()=> 'Hello '+WorldSignal.get()) })")}. This is read-only signal
-			its value is computed based on given function and updated when any signal used in the function changes.
-		`),
-		el("p").append(...T`
-			To represent part of the template filled dynamically based on the signal value use
-			${el("code", "S.el(signal, DOMgenerator)")}. This was already used in the todo example above or see:
 		`),
 		el(example, { src: fileURL("./components/examples/signals/dom-el.js"), page_id }),
 
+		el(h3, t`Best Practices for Signals`),
+		el("p").append(...T`
+			Follow these guidelines to get the most out of signals:
+		`),
+		el("ol").append(
+			el("li").append(...T`
+				${el("strong", "Keep signals small and focused")}: Use many small signals rather than a few large ones
+			`),
+			el("li").append(...T`
+				${el("strong", "Use derived signals for computations")}: Don't recompute values in multiple places
+			`),
+			el("li").append(...T`
+				${el("strong", "Clean up signal subscriptions")}: Use AbortController or scope.host() to prevent memory leaks
+			`),
+			el("li").append(...T`
+				${el("strong", "Use actions for complex state")}: Don't directly mutate objects or arrays in signals
+			`),
+			el("li").append(...T`
+				${el("strong", "Avoid infinite loops")}: Be careful when one signal updates another in a subscription
+			`)
+		),
+
+		el("div", { class: "dde-troubleshooting" }).append(
+			el("h4", t`Common Signal Pitfalls`),
+			el("dl").append(
+				el("dt", t`UI not updating when array/object changes`),
+				el("dd", t`Use signal actions instead of direct mutation`),
+
+				el("dt", t`Infinite update loops`),
+				el("dd", t`Check for circular dependencies between signals`),
+
+				el("dt", t`Memory leaks`),
+				el("dd", t`Use AbortController or scope.host() to clean up subscriptions`),
+
+				el("dt", t`Multiple elements updating unnecessarily`),
+				el("dd", t`Split large signals into smaller, more focused ones`)
+			)
+		),
+
 		el(mnemonic)
 	);
 }

docs/p05-scopes.html.js

@@ -1,7 +1,7 @@
 import { T, t } from "./utils/index.js";
 export const info= {
-	title: t`Scopes and components`,
+	title: t`Scopes and Components`,
-	description: t`Organizing UI into components`,
+	description: t`Organizing UI into reusable, manageable components`,
 };
 
 import { el } from "deka-dom-el";
@@ -28,60 +28,226 @@ const references= {
 export function page({ pkg, info }){
 	const page_id= info.id;
 	return el(simplePage, { info, pkg }).append(
-		el("h2", t`Using functions as UI components`),
+		el("h2", t`Building Maintainable UIs with Scopes and Components`),
 		el("p").append(...T`
-			For state-less components we can use functions as UI components (see “Elements” page). But in real life,
+			Scopes provide a structured way to organize your UI code into reusable components that properly
-			we may need to handle the component live-cycle and provide JavaScript the way to properly use
+			manage their lifecycle, handle cleanup, and maintain clear boundaries between different parts of your application.
-			the ${el("a", { textContent: t`Garbage collection`, ...references.garbage_collection })}.
 		`),
+		el("div", { class: "dde-callout" }).append(
+			el("h4", t`Why Use Scopes?`),
+			el("ul").append(
+				el("li", t`Automatic resource cleanup when components are removed from DOM`),
+				el("li", t`Clear component boundaries with explicit host elements`),
+				el("li", t`Simplified event handling with proper "this" binding`),
+				el("li", t`Seamless integration with signals for reactive components`),
+				el("li", t`Better memory management with ${el("a", { textContent: t`GC`, ...references.garbage_collection })}`)
+			)
+		),
 		el(code, { src: fileURL("./components/examples/scopes/intro.js"), page_id }),
-		el("p").append(...T`The library therefore use ${el("em", t`scopes`)} to provide these functionalities.`),
 
-		el(h3, t`Scopes and hosts`),
+		el(h3, t`Understanding Host Elements and Scopes`),
+		el("div", { class: "dde-illustration" }).append(
+			el("h4", t`Component Anatomy`),
+			el("pre").append(el("code", `
+┌─────────────────────────────────┐
+│ // 1. Component scope created   │
+│ el(MyComponent);                │
+│                                 │
+│ function MyComponent() {        │
+│   // 2. access the host element │
+│   const { host } = scope;       │
+│                                 │
+│   // 3. Add behavior to host    │
+│   host(                         │
+│     on.click(handleClick)       │
+│   );                            │
+│                                 │
+│   // 4. Return the host element │
+│   return el("div", {           │
+│     className: "my-component"   │
+│   }).append(                    │
+│     el("h2", "Title"),          │
+│     el("p", "Content")          │
+│   );                            │
+│ }                               │
+└─────────────────────────────────┘
+			`))
+		),
 		el("p").append(...T`
-			The ${el("strong", "host")} is the name for the element representing the component. This is typically
+			The ${el("strong", "host element")} is the root element of your component - typically the element returned
-			element returned by function. To get reference, you can use ${el("code", "scope.host()")} to applly addons
+			by your component function. It serves as the identity of your component in the DOM.
-			just use ${el("code", "scope.host(...<addons>)")}.
 		`),
+		el("div", { class: "dde-function-table" }).append(
+			el("h4", t`scope.host()`),
+			el("dl").append(
+				el("dt", t`When called with no arguments`),
+				el("dd", t`Returns a reference to the host element (the root element of your component)`),
+
+				el("dt", t`When called with addons/callbacks`),
+				el("dd", t`Applies the addons to the host element and returns the host element`)
+			)
+		),
 		el(example, { src: fileURL("./components/examples/scopes/scopes-and-hosts.js"), page_id }),
+
+		el("div", { class: "dde-tip" }).append(
+			el("p").append(...T`
+				${el("strong", "Best Practice:")} Always capture the host reference at the beginning of your component function
+				using ${el("code", "const { host } = scope")} to avoid scope-related issues, especially with asynchronous code.
+			`)
+		),
+
+		el(h3, t`Class-Based Components`),
 		el("p").append(...T`
-			To better understanding we implement function ${el("code", "elClass")} helping to create component as
+			While functional components are the primary pattern in DDE, you can also create class-based components
-			class instances.
+			for more structured organization of component logic.
 		`),
 		el(example, { src: fileURL("./components/examples/scopes/class-component.js"), page_id }),
+
 		el("p").append(...T`
-			As you can see, the ${el("code", "scope.host()")} is stored temporarily and synchronously. Therefore, at
+			This pattern can be useful when:
-			least in the beginning of using library, it is the good practise to store ${el("code", "host")} in the root
-			of your component. As it may be changed, typically when there is asynchronous code in the component.
 		`),
+		el("ul").append(
+			el("li", t`You have complex component logic that benefits from object-oriented organization`),
+			el("li", t`You need private methods and properties for your component`),
+			el("li", t`You're transitioning from another class-based component system`)
+		),
+		el("div", { class: "dde-tip" }).append(
+			el("p").append(...T`
+				${el("strong", "Note:")} Even with class-based components, follow the best practice of storing the host reference
+				early in your component code. This ensures proper access to the host throughout the component's lifecycle.
+			`)
+		),
 		el(code, { src: fileURL("./components/examples/scopes/good-practise.js"), page_id }),
 
-		el(h3, t`Scopes, signals and cleaning magic`),
+		el(h3, t`Automatic Cleanup with Scopes`),
 		el("p").append(...T`
-			The ${el("code", "host")} is internally used to register the cleaning procedure, when the component
+			One of the most powerful features of scopes is automatic cleanup when components are removed from the DOM.
-			(${el("code", "host")} element) is removed from the DOM.
+			This prevents memory leaks and ensures resources are properly released.
 		`),
+		el("div", { class: "dde-illustration" }).append(
+			el("h4", t`Lifecycle Flow`),
+			el("pre").append(el("code", `
+1. Component created → scope established
+2. Component added to DOM → connected event
+3. Component interactions happen
+4. Component removed from DOM → disconnected event
+5. Automatic cleanup of:
+	- Event listeners
+	- Signal subscriptions
+	- Custom cleanup code
+			`))
+		),
 		el(example, { src: fileURL("./components/examples/scopes/cleaning.js"), page_id }),
+
+		el("div", { class: "dde-note" }).append(
+			el("p").append(...T`
+				In this example, when you click "Remove", the component is removed from the DOM, and all its associated
+				resources are automatically cleaned up, including the signal subscription that updates the text content.
+				This happens because the library internally registers a disconnected event handler on the host element.
+			`)
+		),
+
+		el(h3, t`Declarative vs Imperative Components`),
 		el("p").append(...T`
-			The text content of the paragraph is changing when the value of the signal ${el("code", "textContent")}
+			Scopes work best with a declarative approach to UI building, especially when combined
-			is changed. Internally, there is association between ${el("code", "textContent")} and the paragraph,
+			with ${el("a", { textContent: "signals", ...references.signals })} for state management.
-			similar to using ${el("code", `S.on(textContent, /* ${t`update the paragraph`} */)`)}.
-		`),
-		el("p").append(...T`
-			This listener must be removed when the component is removed from the DOM. To do it, the library assign
-			internally ${el("code", `on.disconnected(/* ${t`remove the listener`} */)(host())`)} to the host element.
-		`),
-		el("p", { className: "notice" }).append(...T`
-			The library DOM API and signals works ideally when used declaratively. It means, you split your app logic
-			into three parts as it was itroduced in ${el("a", { textContent: "Signals", ...references.signals })}.
 		`),
+		el("div", { class: "dde-tabs" }).append(
+			el("div", { class: "tab", "data-tab": "declarative" }).append(
+				el("h4", t`✅ Declarative Approach`),
+				el("p", t`Define what your UI should look like based on state:`),
+				el("pre").append(el("code", `function Counter() {
+	const { host } = scope;
+
+	// Define state
+	const count = S(0);
+
+	// Define behavior
+	const increment = () => count.set(count.get() + 1);
+
+	// UI automatically updates when count changes
+	return el("div").append(
+		el("p", S(() => "Count: " + count.get())),
+		el("button", {
+			onclick: increment,
+			textContent: "Increment"
+		})
+	);
+}`))
+			),
+			el("div", { class: "tab", "data-tab": "imperative" }).append(
+				el("h4", t`⚠️ Imperative Approach`),
+				el("p", t`Manually update the DOM in response to events:`),
+				el("pre").append(el("code", `function Counter() {
+	const { host } = scope;
+
+	let count = 0;
+	const counterText = el("p", "Count: 0");
+
+	// Manually update DOM element
+	const increment = () => {
+		count++;
+		counterText.textContent = "Count: " + count;
+	};
+
+	return el("div").append(
+		counterText,
+		el("button", {
+			onclick: increment,
+			textContent: "Increment"
+		})
+	);
+}`))
+			)
+		),
+
 		el(code, { src: fileURL("./components/examples/scopes/declarative.js"), page_id }),
-		el("p").append(...T`
+
-			Strictly speaking, the imperative way of using the library is not prohibited. Just be careful (rather avoid)
+		el("div", { class: "dde-note" }).append(
-			mixing declarative approach (using signals) and imperative manipulation of elements.
+			el("p").append(...T`
-		`),
+				While DDE supports both declarative and imperative approaches, the declarative style is recommended
+				as it leads to more maintainable code with fewer opportunities for bugs. Signals handle the complexity
+				of keeping your UI in sync with your data.
+			`)
+		),
 		el(code, { src: fileURL("./components/examples/scopes/imperative.js"), page_id }),
 
+		el(h3, t`Best Practices for Scopes and Components`),
+		el("ol").append(
+			el("li").append(...T`
+				${el("strong", "Capture host early:")} Use ${el("code", "const { host } = scope")} at component start
+			`),
+			el("li").append(...T`
+				${el("strong", "Return a single root element:")} Components should have one host element that contains all others
+			`),
+			el("li").append(...T`
+				${el("strong", "Prefer declarative patterns:")} Use signals to drive UI updates rather than manual DOM manipulation
+			`),
+			el("li").append(...T`
+				${el("strong", "Keep components focused:")} Each component should do one thing well
+			`),
+			el("li").append(...T`
+				${el("strong", "Add explicit cleanup:")} For resources not managed by DDE, use ${el("code", "on.disconnected")}
+			`)
+		),
+
+		el("div", { class: "dde-troubleshooting" }).append(
+			el("h4", t`Common Scope Pitfalls`),
+			el("dl").append(
+				el("dt", t`Losing host reference in async code`),
+				el("dd", t`Store host reference early with const { host } = scope`),
+
+				el("dt", t`Memory leaks from custom resources`),
+				el("dd", t`Use host(on.disconnected(cleanup)) for manual resource cleanup`),
+
+				el("dt", t`Event handlers with incorrect 'this'`),
+				el("dd", t`Use arrow functions or .bind() to preserve context`),
+
+				el("dt", t`Mixing declarative and imperative styles`),
+				el("dd", t`Choose one approach and be consistent throughout a component`)
+			)
+		),
+
 		el(mnemonic)
 	);
 }

docs/p06-customElement.html.js

@@ -53,90 +53,236 @@ const references= {
 export function page({ pkg, info }){
 	const page_id= info.id;
 	return el(simplePage, { info, pkg }).append(
-		el("h2", t`Using web components in combinantion with DDE`),
+		el("h2", t`Using Web Components with DDE: Better Together`),
 		el("p").append(...T`
-			The DDE library allows for use within ${el("a", references.mdn_web_components).append( el("strong",
+			DDE pairs powerfully with ${el("a", references.mdn_web_components).append(el("strong", t`Web Components`))}
-			t`Web Components`) )} for dom-tree generation. However, in order to be able to use signals (possibly
+			to create reusable, encapsulated custom elements with all the benefits of DDE's declarative DOM
-			mapping to registered ${el("a", references.mdn_observedAttributes).append( el("code", "observedAttributes")
+			construction and reactivity system.
-			)}) and additional functionality is (unfortunately) required to use helpers provided by the library.
 		`),
+		el("div", { class: "dde-callout" }).append(
+			el("h4", t`Why Combine DDE with Web Components?`),
+			el("ul").append(
+				el("li", t`Declarative DOM creation within your components`),
+				el("li", t`Reactive attribute updates through signals`),
+				el("li", t`Simplified event handling with the same events API`),
+				el("li", t`Clean component lifecycle management`),
+				el("li", t`Improved code organization with scopes`)
+			)
+		),
 		el(code, { src: fileURL("./components/examples/customElement/intro.js"), page_id }),
 
-		el(h3, t`Custom Elements Introduction`),
+		el(h3, t`Getting Started: Web Components Basics`),
 		el("p").append(...T`
-			Web Components, specifically Custom Elements, are a set of web platform APIs that allow you to create
+			Web Components are a set of standard browser APIs that let you create custom HTML elements with
-			new HTML tags with custom functionality encapsulated within them. This allows for the creation of reusable
+			encapsulated functionality. They consist of three main technologies:
-			components that can be used across web applications.
-		`),
-		el("p").append(...T`
-			To start with, let’s see how to use native Custom Elements. As starting point please read
-			${el("a", references.mdn_custom_elements).append( el("strong", t`Using Custom Elements`), t` on MDN` )}.
-			To sum up and for mnemonic see following code overview:
-		`),
-		el(code, { src: fileURL("./components/examples/customElement/native-basic.js"), page_id }),
-		el("p").append(...T`
-			For more advanced use of Custom Elements, the summary ${el("a", references.custom_elements_tips)
-			.append( el("strong", t`Handy Custom Elements Patterns`) )} may be useful. Especially pay attention to
-			linking HTML attributes and defining setters/getters, this is very helpful to use in combination with
-			the library (${el("code", `el(HTMLCustomElement.tagName, { customAttribute: "${t`new-value`}" });`)}).
-		`),
-		el("p").append(...T`
-			Also see the Life Cycle Events sections, very similarly we would like to use
-			${el("a", { textContent: t`DDE events`, href: "./p03-events.html", title: t`See events part of the library
-			documentation` })}. To do it, the library provides function ${el("code", "customElementWithDDE")}…
-		`),
-		el(example, { src: fileURL("./components/examples/customElement/customElementWithDDE.js"), page_id }),
-
-		el("h3", t`Custom Elements with DDE`),
-		el("p").append(...T`
-			The ${el("code", "customElementWithDDE")} function is only (small) part of the inregration of the library.
-			More important for coexistence is render component function as a body of the Custom Element. For that, you
-			can use ${el("code", "customElementRender")} with arguments instance reference, target for connection,
-			render function and optional properties (will be passed to the render function) see later…
-		`),
-		el(example, { src: fileURL("./components/examples/customElement/dde.js"), page_id }),
-		el("p").append(...T`
-			…as you can see, you can use components created based on the documentation previously introduced. To unlock
-			full potential, use with combination ${el("code", "customElementWithDDE")} (allows to use livecycle events)
-			and ${el("code", "observedAttributes")} (converts attributes to render function arguments —
-			${el("em", "default")}) or ${el("code", "S.observedAttributes")} (converts attributes to signals).
-		`),
-		el(example, { src: fileURL("./components/examples/customElement/observedAttributes.js"), page_id }),
-
-
-		el(h3, t`Shadow DOM`),
-		el("p").append(...T`
-			Shadow DOM is a web platform feature that allows for the encapsulation of a component’s internal DOM tree
-			from the rest of the document. This means that styles and scripts applied to the document will not affect
-			the component’s internal DOM, and vice versa.
-		`),
-		el(example, { src: fileURL("./components/examples/customElement/shadowRoot.js"), page_id }),
-		el("p").append(...T`
-			Regarding to ${el("code", "this.attachShadow({ mode: 'open' })")} see quick overview
-			${el("a", { textContent: t`Using Shadow DOM`, ...references.mdn_shadow_dom_depth })}. An another source of
-			information can be ${el("a", { textContent: t`Shadow DOM in Depth`, ...references.shadow_dom_depth })}.
-		`),
-		el("p").append(...T`
-			Besides the encapsulation, the Shadow DOM allows for using the ${el("a", references.mdn_shadow_dom_slot).append(
-			el("strong", t`<slot>`), t` element(s)`)}. You can simulate this feature using ${el("code", "simulateSlots")}:
-		`),
-		el(example, { src: fileURL("./components/examples/customElement/simulateSlots.js"), page_id }),
-		el("p").append(...T`
-			To sum up:
 		`),
 		el("ul").append(
 			el("li").append(...T`
-				The use of shadow DOM to encapsulate the internal structure of the custom element, which affects how
+				${el("strong", "Custom Elements:")} Create your own HTML tags with JS-defined behavior
-				the custom element can be styled and modified using JavaScript and CSS.
 			`),
 			el("li").append(...T`
-				The ability to access and modify the internal structure of the custom element using JavaScript, which
+				${el("strong", "Shadow DOM:")} Encapsulate styles and markup within a component
-				is affected by the use of shadow DOM and the mode of the shadow DOM.
 			`),
 			el("li").append(...T`
-				The use of slots to allow for the insertion of content from the parent document into the custom
+				${el("strong", "HTML Templates:")} Define reusable markup structures
-				element, which is affected by the use of shadow DOM and the mode of the shadow DOM.
+			`)
+		),
+		el("p").append(...T`
+			Let's start with a basic Custom Element example without DDE to establish the foundation:
+		`),
+		el(code, { src: fileURL("./components/examples/customElement/native-basic.js"), page_id }),
+
+		el("div", { class: "dde-note" }).append(
+			el("p").append(...T`
+				For complete information on Web Components, see the
+				${el("a", references.mdn_custom_elements).append(el("strong", t`MDN documentation`))}.
+				Also, ${el("a", references.custom_elements_tips).append(el("strong", t`Handy Custom Elements Patterns`))}
+				provides useful techniques for connecting attributes with properties.
+			`)
+		),
+
+		el(h3, t`DDE Integration: Step 1 - Event Handling`),
+		el("p").append(...T`
+			The first step in integrating DDE with Web Components is enabling DDE's event system to work with your
+			Custom Elements. This is done with ${el("code", "customElementWithDDE")}, which makes your Custom Element
+			compatible with DDE's event handling.
+		`),
+		el("div", { class: "dde-function-table" }).append(
+			el("h4", t`customElementWithDDE`),
+			el("dl").append(
+				el("dt", t`Purpose`),
+				el("dd", t`Enables DDE's event system to work with your Custom Element`),
+				el("dt", t`Usage`),
+				el("dd", t`customElementWithDDE(YourElementClass)`),
+				el("dt", t`Benefits`),
+				el("dd", t`Allows using on.connected(), on.disconnected(), etc. with your element`)
+			)
+		),
+		el(example, { src: fileURL("./components/examples/customElement/customElementWithDDE.js"), page_id }),
+
+		el("div", { class: "dde-tip" }).append(
+			el("p").append(...T`
+				${el("strong", "Key Point:")} The ${el("code", "customElementWithDDE")} function adds event dispatching
+				to your Custom Element lifecycle methods, making them work seamlessly with DDE's event system.
+			`)
+		),
+
+		el(h3, t`DDE Integration: Step 2 - Rendering Components`),
+		el("p").append(...T`
+			The next step is to use DDE's component rendering within your Custom Element. This is done with
+			${el("code", "customElementRender")}, which connects your DDE component function to the Custom Element.
+		`),
+		el("div", { class: "dde-function-table" }).append(
+			el("h4", t`customElementRender`),
+			el("dl").append(
+				el("dt", t`Purpose`),
+				el("dd", t`Connects a DDE component function to a Custom Element`),
+				el("dt", t`Parameters`),
+				el("dd").append(
+					el("ol").append(
+						el("li", t`Target (usually this or this.shadowRoot)`),
+						el("li", t`Component function that returns a DOM tree`),
+						el("li", t`Optional: Attributes transformer function (default or S.observedAttributes)`)
+					)
+				),
+				el("dt", t`Returns`),
+				el("dd", t`The rendered DOM tree`)
+			)
+		),
+		el(example, { src: fileURL("./components/examples/customElement/dde.js"), page_id }),
+
+		el("div", { class: "dde-note" }).append(
+			el("p").append(...T`
+				In this example, we're using Shadow DOM (${el("code", "this.attachShadow()")}) for encapsulation,
+				but you can also render directly to the element with ${el("code", "customElementRender(this, ...)")}.
+			`)
+		),
+
+		el(h3, t`Reactive Web Components with Signals`),
+		el("p").append(...T`
+			One of the most powerful features of integrating DDE with Web Components is connecting HTML attributes
+			to DDE's reactive signals system. This creates truly reactive custom elements.
+		`),
+		el("div", { class: "dde-tip" }).append(
+			el("p").append(...T`
+				${el("strong", "Two Ways to Handle Attributes:")}
 			`),
+			el("ol").append(
+				el("li").append(...T`
+					${el("code", "observedAttributes")} - Passes attributes as regular values (static)
+				`),
+				el("li").append(...T`
+					${el("code", "S.observedAttributes")} - Transforms attributes into signals (reactive)
+				`)
+			)
+		),
+		el("p").append(...T`
+			Using ${el("code", "S.observedAttributes")} creates a reactive connection between your element's attributes
+			and its internal rendering. When attributes change, your component automatically updates!
+		`),
+		el(example, { src: fileURL("./components/examples/customElement/observedAttributes.js"), page_id }),
+
+		el("div", { class: "dde-callout" }).append(
+			el("h4", t`How S.observedAttributes Works`),
+			el("p").append(...T`
+				1. Takes each attribute listed in static observedAttributes
+				2. Creates a DDE signal for each one
+				3. Automatically updates these signals when attributes change
+				4. Passes the signals to your component function
+				5. Your component reacts to changes through signal subscriptions
+			`)
+		),
+
+		el(h3, t`Working with Shadow DOM`),
+		el("p").append(...T`
+			Shadow DOM provides encapsulation for your component's styles and markup. When using DDE with Shadow DOM,
+			you get the best of both worlds: encapsulation plus declarative DOM creation.
+		`),
+		el("div", { class: "dde-illustration" }).append(
+			el("h4", t`Shadow DOM Encapsulation`),
+			el("pre").append(el("code", `
+┌─────────────────────────────────┐
+│ <my-custom-element>             │
+│                                 │
+│  ┌─────────────────────────┐    │
+│  │ #shadow-root           │    │
+│  │                         │    │
+│  │  Created with DDE:      │    │
+│  │  ┌─────────────────┐    │    │
+│  │  │ <div>           │    │    │
+│  │  │   <h2>Title</h2> │    │    │
+│  │  │   <p>Content</p> │    │    │
+│  │  └─────────────────┘    │    │
+│  │                         │    │
+│  └─────────────────────────┘    │
+│                                 │
+└─────────────────────────────────┘
+			`))
+		),
+		el(example, { src: fileURL("./components/examples/customElement/shadowRoot.js"), page_id }),
+
+		el("p").append(...T`
+			For more information on Shadow DOM, see
+			${el("a", { textContent: t`Using Shadow DOM`, ...references.mdn_shadow_dom_depth })}, or the comprehensive
+			${el("a", { textContent: t`Shadow DOM in Depth`, ...references.shadow_dom_depth })}.
+		`),
+
+		el(h3, t`Working with Slots`),
+		el("p").append(...T`
+			Slots allow users of your component to insert content inside it. When using DDE, you can simulate the
+			slot mechanism with the ${el("code", "simulateSlots")} function:
+		`),
+		el("div", { class: "dde-function-table" }).append(
+			el("h4", t`simulateSlots`),
+			el("dl").append(
+				el("dt", t`Purpose`),
+				el("dd", t`Provides slot functionality when you cannot/do not want to use shadow DOM`),
+				el("dt", t`Parameters`),
+				el("dd", t`A mapping object of slot names to DOM elements`)
+			)
+		),
+		el(example, { src: fileURL("./components/examples/customElement/simulateSlots.js"), page_id }),
+
+		el("div", { class: "dde-tip" }).append(
+			el("p").append(...T`
+				${el("strong", "When to use simulateSlots:")} This approach is useful when you need to distribute
+				content from the light DOM into specific locations in the shadow DOM, particularly in environments
+				where native slots might not be fully supported.
+			`)
+		),
+
+		el(h3, t`Best Practices for Web Components with DDE`),
+		el("p").append(...T`
+			When combining DDE with Web Components, follow these recommendations:
+		`),
+		el("ol").append(
+			el("li").append(...T`
+				${el("strong", "Always use customElementWithDDE")} to enable event integration
+			`),
+			el("li").append(...T`
+				${el("strong", "Prefer S.observedAttributes")} for reactive attribute connections
+			`),
+			el("li").append(...T`
+				${el("strong", "Create reusable component functions")} that your custom elements render
+			`),
+			el("li").append(...T`
+				${el("strong", "Use scope.host()")} to clean up event listeners and subscriptions
+			`),
+			el("li").append(...T`
+				${el("strong", "Add setters and getters")} for better property access to your element
+			`)
+		),
+
+		el("div", { class: "dde-troubleshooting" }).append(
+			el("h4", t`Common Issues`),
+			el("dl").append(
+				el("dt", t`Events not firing properly`),
+				el("dd", t`Make sure you called customElementWithDDE before defining the element`),
+				el("dt", t`Attributes not updating`),
+				el("dd", t`Check that you've properly listed them in static observedAttributes`),
+				el("dt", t`Component not rendering`),
+				el("dd", t`Verify customElementRender is called in connectedCallback, not constructor`)
+			)
 		),
 
 		el(mnemonic)