From 4c6a395de093dce24c688276a8b04a93093fd118 Mon Sep 17 00:00:00 2001
From: metamuffin <metamuffin@disroot.org>
Date: Sun, 1 Oct 2023 11:27:59 +0200
Subject: init

---
 src/element.ts    | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/observable.ts | 34 +++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)
 create mode 100644 src/element.ts
 create mode 100644 src/observable.ts

(limited to 'src')

diff --git a/src/element.ts b/src/element.ts
new file mode 100644
index 0000000..9880748
--- /dev/null
+++ b/src/element.ts
@@ -0,0 +1,60 @@
+/*
+    This file is part of jshelper (https://codeberg.org/metamuffin/jshelper)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2023 metamuffin <metamuffin.org>
+*/
+import { OVar } from "./observable.ts";
+
+interface Opts<E> {
+    class?: string[] | string,
+    id?: string,
+    src?: string,
+    for?: string,
+    type?: string,
+    href?: string,
+    onclick?: (e: E) => void,
+    onchange?: (e: E) => void,
+}
+
+function apply_opts<E extends HTMLElement>(e: E, o: Opts<E>): (() => unknown) | void {
+    if (o.id) e.id = o.id
+    if (o.for) (e as unknown as HTMLLabelElement).htmlFor = o.for
+    if (o.type && e instanceof HTMLInputElement) e.type = o.type
+    if (o.href && e instanceof HTMLAnchorElement) e.href = o.href;
+    if (o.onclick) e.addEventListener("click", () => o.onclick!(e))
+    if (o.onchange) e.addEventListener("change", () => o.onchange!(e))
+    if (typeof o?.class == "string") e.classList.add(o.class)
+    if (typeof o?.class == "object") e.classList.add(...o.class)
+}
+
+type EEl<K extends keyof HTMLElementTagNameMap> = string | HTMLElement | Opts<HTMLElementTagNameMap[K]> | OVar<Opts<HTMLElementTagNameMap[K]>> | OVar<string> | OVar<HTMLElement> | OVar<HTMLUListElement> | undefined;
+
+export function e<K extends keyof HTMLElementTagNameMap>(name: K, ...children: EEl<K>[]): HTMLElementTagNameMap[K] {
+    const el = document.createElement(name)
+    for (const c of children) e_apply(el, c)
+    return el
+}
+
+function e_apply<K extends keyof HTMLElementTagNameMap, C extends EEl<K>>(el: HTMLElementTagNameMap[K], c: C): () => unknown {
+    if (typeof c == "undefined") {
+        return () => { }
+    }
+    if (typeof c == "string") {
+        el.append(c)
+        return () => {
+            el.textContent = ""
+        }
+    }
+    else if (c instanceof HTMLElement) {
+        el.append(c)
+        return () => el.removeChild(c)
+    }
+    else if (c instanceof OVar) {
+        let undo_last: () => unknown;
+        return c.onchangeinit(val => {
+            if (undo_last) undo_last()
+            undo_last = e_apply(el, val)
+        })
+    }
+    else return apply_opts(el, c) ?? (() => { })
+}
diff --git a/src/observable.ts b/src/observable.ts
new file mode 100644
index 0000000..3e1308c
--- /dev/null
+++ b/src/observable.ts
@@ -0,0 +1,34 @@
+/*
+    This file is part of jshelper (https://codeberg.org/metamuffin/jshelper)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2023 metamuffin <metamuffin.org>
+*/
+export class OVar<T> {
+    private _value: T
+    private observers: ((v: T) => unknown)[] = []
+
+    constructor(initial: T) {
+        this._value = initial;
+    }
+
+    get value() { return this._value }
+    set value(v: T) {
+        this._value = v;
+        this.observers.forEach(o => o(v))
+    }
+
+    onchange(handler: (v: T) => unknown): () => unknown {
+        this.observers.push(handler)
+        return () => this.observers = this.observers.filter(o => o != handler)
+    }
+    onchangeinit(handler: (v: T) => unknown): () => unknown {
+        const abort = this.onchange(handler)
+        handler(this.value)
+        return abort
+    }
+    map<U>(fn: (v: T) => U): OVar<U> {
+        const uv = new OVar(fn(this.value))
+        this.onchange(v => uv.value = fn(v))
+        return uv;
+    }
+}
-- 
cgit v1.2.3-70-g09d2