Remove AlchemyHTMLElement

AGENTS.md

@@ -188,7 +188,7 @@ The admin interface uses a **hybrid architecture**:
 
 **Modern Web Components** (preferred for new features):
 - Custom elements in `app/javascript/alchemy_admin/components/`
-- Base class: `AlchemyHTMLElement` (extends `HTMLElement`)
+- Extend `HTMLElement` directly; do all DOM work in `connectedCallback`
 - Examples: `alchemy-sitemap`, `alchemy-element-editor`, `alchemy-datepicker`
 - Vanilla JavaScript (no framework dependency)
 

app/javascript/alchemy_admin/components/char_counter.js

@@ -1,30 +1,36 @@
 /**
  * Show the character counter below input fields and textareas
  */
-import { AlchemyHTMLElement } from "alchemy_admin/components/alchemy_html_element"
 import { translate } from "alchemy_admin/i18n"
 
-class CharCounter extends AlchemyHTMLElement {
-  static properties = {
-    maxChars: { default: 60 }
-  }
-  connected() {
+class CharCounter extends HTMLElement {
+  connectedCallback() {
     this.translation = translate("allowed_chars", this.maxChars)
     this.formField = this.getFormField()
 
     if (this.formField) {
       this.createDisplayElement()
       this.countCharacters()
-      this.formField.addEventListener("keyup", () => this.countCharacters()) // add arrow function to get a implicit this - binding
+      this.formField.addEventListener("keyup", this)
     }
   }
 
+  disconnectedCallback() {
+    this.formField?.removeEventListener("keyup", this)
+  }
+
+  handleEvent(event) {
+    if (event.type === "keyup") this.countCharacters()
+  }
+
   getFormField() {
     const formFields = this.querySelectorAll("input, textarea")
     return formFields.length > 0 ? formFields[0] : undefined
   }
 
   createDisplayElement() {
+    this.display = this.querySelector(":scope > .alchemy-char-counter")
+    if (this.display) return
     this.display = document.createElement("small")
     this.display.className = "alchemy-char-counter"
     this.formField.after(this.display)
@@ -35,6 +41,10 @@ class CharCounter extends AlchemyHTMLElement {
     this.display.textContent = `${charLength} ${this.translation}`
     this.display.classList.toggle("too-long", charLength > this.maxChars)
   }
+
+  get maxChars() {
+    return this.getAttribute("max-chars") ?? 60
+  }
 }
 
 customElements.define("alchemy-char-counter", CharCounter)

app/javascript/alchemy_admin/components/datepicker.js

@@ -1,31 +1,24 @@
-import { AlchemyHTMLElement } from "alchemy_admin/components/alchemy_html_element"
 import { translate, currentLocale } from "alchemy_admin/i18n"
 import flatpickr from "flatpickr"
 
 const locale = currentLocale()
 
-class Datepicker extends AlchemyHTMLElement {
-  static properties = {
-    inputType: { default: "date" }
-  }
-
-  constructor() {
-    super()
-    this.flatpickr = undefined
-  }
-
+class Datepicker extends HTMLElement {
   // Load the locales for flatpickr before setting it up.
-  async connected() {
+  async connectedCallback() {
     // English is the default locale for flatpickr, so we don't need to load it
     if (locale !== "en") {
       await import(`flatpickr/${locale}.js`)
     }
+    // Bail out if the element was disconnected while the locale was loading.
+    // Otherwise flatpickr would leak a calendar onto a detached input.
+    if (!this.isConnected) return
 
     this.flatpickr = flatpickr(this.inputField, this.flatpickrOptions)
   }
 
-  disconnected() {
-    this.flatpickr.destroy()
+  disconnectedCallback() {
+    this.flatpickr?.destroy()
   }
 
   get flatpickrOptions() {
@@ -56,6 +49,10 @@ class Datepicker extends AlchemyHTMLElement {
   get inputField() {
     return this.querySelector("input")
   }
+
+  get inputType() {
+    return this.getAttribute("input-type") || "date"
+  }
 }
 
 customElements.define("alchemy-datepicker", Datepicker)

app/javascript/alchemy_admin/components/overlay.js

@@ -1,13 +1,11 @@
-import { AlchemyHTMLElement } from "alchemy_admin/components/alchemy_html_element"
-
-class Overlay extends AlchemyHTMLElement {
-  render() {
-    return `
+class Overlay extends HTMLElement {
+  connectedCallback() {
+    this.innerHTML = `
       <alchemy-spinner></alchemy-spinner>
       <div id="overlay_text_box">
-        <span id="overlay_text">${this.getAttribute("text")}</span>
+        <span id="overlay_text">${this.getAttribute("text") ?? ""}</span>
       </div>
-      `
+    `
   }
 
   set show(value) {

app/javascript/alchemy_admin/components/remote_select.js

@@ -1,34 +1,38 @@
-import { AlchemyHTMLElement } from "alchemy_admin/components/alchemy_html_element"
 import { setupSelectLocale } from "alchemy_admin/i18n"
 
 export function hightlightTerm(name, term) {
   return name.replace(new RegExp(term, "gi"), (match) => `<em>${match}</em>`)
 }
 
-export class RemoteSelect extends AlchemyHTMLElement {
-  static properties = {
-    allowClear: { default: false },
-    selection: { default: undefined },
-    placeholder: { default: "" },
-    queryParams: { default: "{}" },
-    url: { default: "" }
-  }
+export class RemoteSelect extends HTMLElement {
+  #select2 = null
 
-  async connected() {
+  async connectedCallback() {
     await setupSelectLocale()
+    // Bail out if the element was disconnected while the locale was loading.
+    // Otherwise Select2 would leak onto a detached input.
+    if (!this.isConnected) return
 
     this.input.classList.add("alchemy_selectbox")
 
-    $(this.input)
+    this.#select2 = $(this.input)
       .select2(this.select2Config)
-      .on("select2-open", (evt) => {
-        this.onOpen(evt)
-      })
-      .on("change", (evt) => {
-        this.onChange(evt)
-      })
+      .on("select2-open", this.#onOpen)
+      .on("change", this.#onChange)
   }
 
+  disconnectedCallback() {
+    if (this.#select2) {
+      this.#select2.off("select2-open", this.#onOpen)
+      this.#select2.off("change", this.#onChange)
+      this.#select2.select2("destroy")
+      this.#select2 = null
+    }
+  }
+
+  #onOpen = (evt) => this.onOpen(evt)
+  #onChange = (evt) => this.onChange(evt)
+
   /**
    * Optional on change handler called by Select2.
    * @param {Event} event
@@ -54,6 +58,38 @@ export class RemoteSelect extends AlchemyHTMLElement {
     }, 100)
   }
 
+  /**
+   * Dispatches a custom event with given name, namespaced under `Alchemy.`.
+   * Subclasses may call this to emit their own events.
+   * @param {string} name The name of the custom event
+   * @param {object} detail Optional event details
+   */
+  dispatchCustomEvent(name, detail = {}) {
+    this.dispatchEvent(
+      new CustomEvent(`Alchemy.${name}`, { bubbles: true, detail })
+    )
+  }
+
+  get allowClear() {
+    return this.hasAttribute("allow-clear")
+  }
+
+  get selection() {
+    return this.getAttribute("selection")
+  }
+
+  get placeholder() {
+    return this.getAttribute("placeholder") ?? ""
+  }
+
+  get queryParams() {
+    return this.getAttribute("query-params") ?? "{}"
+  }
+
+  get url() {
+    return this.getAttribute("url") ?? ""
+  }
+
   get input() {
     return this.getElementsByTagName("input")[0]
   }

app/javascript/alchemy_admin/components/spinner.js

@@ -1,15 +1,7 @@
-import { AlchemyHTMLElement } from "alchemy_admin/components/alchemy_html_element"
-
-class Spinner extends AlchemyHTMLElement {
-  static properties = {
-    size: { default: "medium" },
-    color: { default: "currentColor" }
-  }
-
-  render() {
+class Spinner extends HTMLElement {
+  connectedCallback() {
     this.className = `spinner spinner--${this.size}`
-
-    return `
+    this.innerHTML = `
       <svg width="100%" viewBox="0 0 28 28" style="--spinner-color: ${this.color}">
         <path
           class="hex1"
@@ -26,6 +18,14 @@ class Spinner extends AlchemyHTMLElement {
       </svg>
     `
   }
+
+  get size() {
+    return this.getAttribute("size") || "medium"
+  }
+
+  get color() {
+    return this.getAttribute("color") || "currentColor"
+  }
 }
 
 customElements.define("alchemy-spinner", Spinner)