+FEATURE: double entry info

views/transform/duplicate-warning.js

@@ -0,0 +1,96 @@
+const DEBOUNCE_DELAY_MS = 100;
+
+export class DuplicateWarningChecker extends HTMLElement {
+	constructor() {
+		super();
+		this._fields = null;
+		this._boundHandlers = new Map();
+	}
+
+	connectedCallback() {
+		// Find all fields marked for duplicate checking
+		this._fields = document.querySelectorAll("[data-duplicate-check]");
+
+		this._fields.forEach((field) => {
+			const handler = this._createHandler(field);
+			this._boundHandlers.set(field, handler);
+			field.addEventListener("input", handler);
+		});
+	}
+
+	disconnectedCallback() {
+		this._boundHandlers.forEach((handler, field) => {
+			field.removeEventListener("input", handler);
+		});
+		this._boundHandlers.clear();
+	}
+
+	_createHandler(field) {
+		let timeout = null;
+		return (event) => {
+			if (timeout) {
+				clearTimeout(timeout);
+			}
+			timeout = setTimeout(() => {
+				this._checkDuplicates(field);
+			}, DEBOUNCE_DELAY_MS);
+		};
+	}
+
+	async _checkDuplicates(field) {
+		const value = field.value.trim();
+		const endpoint = field.getAttribute("data-duplicate-endpoint");
+		const resultKey = field.getAttribute("data-duplicate-result-key");
+		const currentId = field.getAttribute("data-duplicate-current-id") || "";
+		const warningEl = document.querySelector(`[data-duplicate-warning-for="${field.id}"]`);
+
+		if (!warningEl || !endpoint || !resultKey) {
+			return;
+		}
+
+		// Hide warning if field is empty
+		if (value === "") {
+			warningEl.classList.add("hidden");
+			return;
+		}
+
+		// Fetch duplicates
+		try {
+			const url = new URL(endpoint, window.location.origin);
+			url.searchParams.set("q", value);
+			url.searchParams.set("limit", "100"); // Get all to filter
+
+			const response = await fetch(url.toString());
+			if (!response.ok) {
+				return;
+			}
+
+			const data = await response.json();
+			const results = data[resultKey] || [];
+
+			// Filter out current item if editing
+			let filtered = results;
+			if (currentId) {
+				filtered = results.filter((item) => item.id !== currentId);
+			}
+
+			// Filter for exact matches only (case-insensitive)
+			const exactMatches = filtered.filter((item) => item.name && item.name.toLowerCase() === value.toLowerCase());
+
+			// Show or hide warning
+			if (exactMatches.length > 0) {
+				const countEl = warningEl.querySelector("[data-duplicate-count]");
+				if (countEl) {
+					const plural = exactMatches.length === 1 ? "" : "e";
+					countEl.textContent = `Der Name ist bereits vorhanden (${exactMatches.length} Treffer${plural})`;
+				}
+				warningEl.classList.remove("hidden");
+			} else {
+				warningEl.classList.add("hidden");
+			}
+		} catch (err) {
+			// Silently fail - don't show errors to user
+			console.error("Duplicate check failed:", err);
+		}
+	}
+}

views/transform/form.css

@@ -45,6 +45,10 @@
 					disabled:opacity-50 py-1 px-3;
 	}
 
+	.dbform .duplicate-warning {
+		@apply text-sm text-sky-600 mt-0.5 pl-2.5 pb-1.5 flex items-center gap-1;
+	}
+
 	/* Status select color coding */
 	.status-select[data-status="Edited"] {
 		@apply bg-green-100 text-green-900;

views/transform/main.js

@@ -27,6 +27,7 @@ import { AlmanachEditPage } from "./almanach-edit.js";
 import { RelationsEditor } from "./relations-editor.js";
 import { EditPage } from "./edit-page.js";
 import { FabMenu } from "./fab-menu.js";
+import { DuplicateWarningChecker } from "./duplicate-warning.js";
 
 const FILTER_LIST_ELEMENT = "filter-list";
 const FAB_MENU_ELEMENT = "fab-menu";
@@ -47,6 +48,7 @@ const ITEMS_EDITOR_ELEMENT = "items-editor";
 const ALMANACH_EDIT_PAGE_ELEMENT = "almanach-edit-page";
 const RELATIONS_EDITOR_ELEMENT = "relations-editor";
 const EDIT_PAGE_ELEMENT = "edit-page";
+const DUPLICATE_WARNING_ELEMENT = "duplicate-warning-checker";
 
 customElements.define(INT_LINK_ELEMENT, IntLink);
 customElements.define(ABBREV_TOOLTIPS_ELEMENT, AbbreviationTooltips);
@@ -67,6 +69,7 @@ customElements.define(ALMANACH_EDIT_PAGE_ELEMENT, AlmanachEditPage);
 customElements.define(RELATIONS_EDITOR_ELEMENT, RelationsEditor);
 customElements.define(EDIT_PAGE_ELEMENT, EditPage);
 customElements.define(FAB_MENU_ELEMENT, FabMenu);
+customElements.define(DUPLICATE_WARNING_ELEMENT, DuplicateWarningChecker);
 
 function PathPlusQuery() {
 	const path = window.location.pathname;