1
0
mirror of https://github.com/jaandrle/deka-dom-el synced 2024-11-21 15:39:36 +01:00
deka-dom-el/docs_src/p05-scopes.html.js
Jan Andrle cd62782c7b
Replace “observable” term with “signal” (#19)
*  refact docs

to make editing (now renaming observables to signal) easier

*   use signal(s) term isntead of observable(s)

*  🔤 version + typo

* 🐛 customElement example (0→S)

* 📺 version in package-lock.json
2024-05-22 21:43:49 +02:00

80 lines
4.0 KiB
JavaScript

export const info= {
title: "Scopes and components",
description: "Organizing UI into components",
};
import { el } from "deka-dom-el";
import { simplePage } from "./layout/simplePage.html.js";
import { example } from "./components/example.html.js";
import { h3 } from "./components/pageUtils.html.js";
import { mnemonic } from "./components/mnemonic/scopes-init.js";
import { code } from "./components/code.html.js";
/** @param {string} url */
const fileURL= url=> new URL(url, import.meta.url);
/** @param {import("./types.d.ts").PageAttrs} attrs */
export function page({ pkg, info }){
const page_id= info.id;
return el(simplePage, { info, pkg }).append(
el("h2", "Using functions as UI components"),
el("p").append(
"For state-less components we can use functions as UI components (see “Elements” page).",
" But in real life, we may need to handle the component live-cycle and provide",
" JavaScript the way to properly use the ", el("a", { textContent: "Garbage collection", href: "https://developer.mozilla.org/en-US/docs/Glossary/Garbage_collection", title: "Garbage collection | MDN" }), "."
),
el(code, { src: fileURL("./components/examples/scopes/intro.js"), page_id }),
el("p").append(
"The library therefore use ", el("em", "scopes"), " to provide these functionalities.",
),
el(h3, "Scopes and hosts"),
el("p").append(
"The ", el("strong", "host"), " is the name for the element representing the component.",
" This is typically element returned by function. To get reference, you can use ",
el("code", "scope.host()"), " to applly addons just use ", el("code", "scope.host(...<addons>)"), "."
),
el(example, { src: fileURL("./components/examples/scopes/scopes-and-hosts.js"), page_id }),
el("p").append(
"To better understanding we implement function ", el("code", "elClass"), " helping to create",
" component as class instances."
),
el(example, { src: fileURL("./components/examples/scopes/class-component.js"), page_id }),
el("p").append(
"As you can see, the ", el("code", "scope.host()"), " is stored temporarily and synchronously.",
" Therefore, at 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(code, { src: fileURL("./components/examples/scopes/good-practise.js"), page_id }),
el(h3, "Scopes, signals and cleaning magic"),
el("p").append(
"The ", el("code", "host"), " is internally used to register the cleaning procedure,",
" when the component (", el("code", "host"), " element) is removed from the DOM."
),
el(example, { src: fileURL("./components/examples/scopes/cleaning.js"), page_id }),
el("p").append(
"The text content of the paragraph is changing when the value of the signal ", el("code", "textContent"),
" is changed. Internally, there is association between ", el("code", "textContent"), " and the paragraph",
" similar to using ", el("code", "S.on(textContent, /* update the paragraph */)"), "."
),
el("p").append(
"This listener must be removed when the component is removed from the DOM. To do it, the library",
" assign internally ", el("code", "on.disconnected(/* remove the listener */)(host())"), " to the host element."
),
el("p", { className: "notice" }).append(
"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", href: "http://localhost:40911/docs/p04-signals#h-introducing-signals" }), "."
),
el(code, { src: fileURL("./components/examples/scopes/declarative.js"), page_id }),
el("p").append(
"Strictly speaking, the imperative way of using the library is not prohibited.",
" Just be careful (rather avoid) mixing declarative approach (using signals)",
" and imperative manipulation of elements.",
),
el(code, { src: fileURL("./components/examples/scopes/imperative.js"), page_id }),
el(mnemonic)
);
}