Update docs for v1.1.0 footer asset selector

- Add changelog entry for new feature
- Update README with asset selection documentation
- Document new /api/assets endpoint
- Update /api/send with footerAssets parameter

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,20 @@ Alle wichtigen Änderungen an diesem Projekt werden hier dokumentiert.
 Das Format basiert auf [Keep a Changelog](https://keepachangelog.com/de/1.0.0/),
 und dieses Projekt folgt [Semantic Versioning](https://semver.org/lang/de/).
 
+## [1.1.0] - 2026-01-16
+
+### Hinzugefügt
+- **Footer-Icon-Auswahl**: Mehrere Icons aus dem `/assets`-Ordner können für den E-Mail-Footer ausgewählt werden
+- Neuer API-Endpunkt `GET /api/assets` zum Abrufen verfügbarer Assets
+- Thumbnail-Grid in der Weboberfläche zur Icon-Auswahl
+- Dynamische Footer-Generierung mit mehreren CID-eingebetteten Bildern
+
+### Geändert
+- `POST /api/send` akzeptiert neues optionales Feld `footerAssets` (Array von Dateinamen)
+- Footer wird nur noch angezeigt wenn mindestens ein Icon ausgewählt wurde
+
+---
+
 ## [1.0.0] - 2026-01-16
 
 ### Hinzugefügt

README.md

@@ -5,8 +5,9 @@ Ein Node.js-basierter Mail-Service mit Weboberfläche zum Versenden von E-Mails
 ## Features
 
 - **Weboberfläche** zum Versenden von E-Mails (Empfänger, CC, Betreff, Text/HTML)
+- **Footer-Icon-Auswahl** - Mehrere Icons aus dem `/assets`-Ordner auswählbar (Thumbnail-Grid)
 - **Persistente Historie** in SQLite-Datenbank
-- **Eingebetteter Bild-Footer** via CID-Attachment (wird ohne "Bilder anzeigen" dargestellt)
+- **Eingebettete Bilder** via CID-Attachment (werden ohne "Bilder anzeigen" dargestellt)
 - **REST-API** für programmatischen Zugriff
 - **Brevo SMTP** mit DKIM/SPF/DMARC-Unterstützung
 
@@ -25,8 +26,10 @@ mail-service/
 │   ├── index.html          # Weboberfläche
 │   ├── style.css           # Styling
 │   └── script.js           # Frontend-Logik
-├── assets/
+├── assets/                 # Footer-Icons (PNG/JPG/GIF/SVG)
-│   └── homeicon.png        # Footer-Bild (40x40 PNG)
+│   ├── homeicon.png
+│   ├── cal.png
+│   └── ...                 # Weitere Icons automatisch verfügbar
 └── data/
     └── emails.db           # SQLite-Datenbank (automatisch erstellt)
 ```
@@ -90,11 +93,22 @@ Server läuft auf: http://localhost:3000
 | Methode | Route | Beschreibung |
 |---------|-------|--------------|
 | GET | `/` | Weboberfläche |
+| GET | `/api/assets` | Verfügbare Footer-Icons abrufen |
 | POST | `/api/send` | E-Mail versenden |
 | GET | `/api/history` | Historie abrufen (letzte 50) |
 | DELETE | `/api/history/:id` | Einzelnen Eintrag löschen |
 | DELETE | `/api/history` | Gesamte Historie löschen |
 
+### GET /api/assets
+
+**Response:**
+```json
+{
+  "success": true,
+  "assets": ["blue.png", "cal.png", "cog.png", "homeicon.png", "psy.png"]
+}
+```
+
 ### POST /api/send
 
 **Request Body:**
@@ -104,10 +118,20 @@ Server läuft auf: http://localhost:3000
   "cc": "optional@example.com",
   "subject": "Betreff",
   "body": "Nachrichteninhalt",
-  "isHtml": false
+  "isHtml": false,
+  "footerAssets": ["homeicon.png", "cal.png"]
 }
 ```
 
+| Feld | Typ | Pflicht | Beschreibung |
+|------|-----|---------|--------------|
+| to | string | Ja | Empfänger-Adresse |
+| cc | string | Nein | CC-Adresse |
+| subject | string | Ja | Betreff |
+| body | string | Ja | Nachrichteninhalt |
+| isHtml | boolean | Nein | true = HTML-Format |
+| footerAssets | string[] | Nein | Icons für Footer (aus /api/assets) |
+
 **Response (Erfolg):**
 ```json
 {
@@ -493,29 +517,11 @@ sendMail(
 
 ### Footer in diesem Projekt anpassen
 
-1. **Bild ändern:** `assets/homeicon.png` ersetzen (empfohlen: 40x40 PNG)
+1. **Neue Icons hinzufügen:** Einfach Bilddateien in den `assets/`-Ordner legen (PNG, JPG, GIF, SVG). Sie erscheinen automatisch in der Auswahl.
 2. **Name ändern:** In `.env` setzen: `MAIL_FOOTER_NAME=Neuer Name`
-3. **Layout ändern:** In `src/mailer.js` die Funktion `getHtmlFooter()` bearbeiten:
+3. **Layout ändern:** In `src/mailer.js` die Funktion `getHtmlFooter(assets)` bearbeiten
 
-```javascript
+**Hinweis:** Der Footer wird nur angezeigt, wenn mindestens ein Icon in der Weboberfläche ausgewählt wurde.
-function getHtmlFooter() {
-  return `
-    <br/><br/>
-    <hr style="border: none; border-top: 1px solid #ddd; margin: 20px 0;"/>
-    <table cellpadding="0" cellspacing="0" style="font-family: Arial, sans-serif;">
-      <tr>
-        <td style="vertical-align: middle; padding-right: 10px;">
-          <img src="cid:homeicon" alt="Home" width="40" height="40" />
-        </td>
-        <td style="vertical-align: middle;">
-          <strong>Absender</strong><br/>
-          ${FOOTER_NAME}
-        </td>
-      </tr>
-    </table>
-  `;
-}
-```
 
 ## Dependencies
 

public/index.html

@@ -43,6 +43,13 @@
           <textarea id="body" name="body" required rows="8" placeholder="Ihre Nachricht..."></textarea>
         </div>
 
+        <div class="form-group">
+          <label>Footer-Icons</label>
+          <div id="assetGrid" class="asset-grid">
+            <p class="loading-message">Lade Assets...</p>
+          </div>
+        </div>
+
         <button type="submit" id="submitBtn">Senden</button>
       </form>
 

public/script.js

@@ -4,21 +4,28 @@ document.addEventListener('DOMContentLoaded', () => {
   const submitBtn = document.getElementById('submitBtn');
   const historyList = document.getElementById('historyList');
   const clearHistoryBtn = document.getElementById('clearHistory');
+  const assetGrid = document.getElementById('assetGrid');
 
-  // Load history on page load
+  // Load history and assets on page load
   loadHistory();
+  loadAssets();
 
   // Form submission
   form.addEventListener('submit', async (e) => {
     e.preventDefault();
 
     const formData = new FormData(form);
+    const selectedAssets = Array.from(
+      document.querySelectorAll('input[name="footerAssets"]:checked')
+    ).map(cb => cb.value);
+
     const data = {
       to: formData.get('to'),
       cc: formData.get('cc') || undefined,
       subject: formData.get('subject'),
       body: formData.get('body'),
-      isHtml: formData.get('format') === 'html'
+      isHtml: formData.get('format') === 'html',
+      footerAssets: selectedAssets
     };
 
     submitBtn.disabled = true;
@@ -80,6 +87,42 @@ document.addEventListener('DOMContentLoaded', () => {
     }
   }
 
+  // Load assets from server
+  async function loadAssets() {
+    try {
+      const response = await fetch('/api/assets');
+      const result = await response.json();
+
+      if (result.success) {
+        renderAssetGrid(result.assets);
+      } else {
+        assetGrid.innerHTML = '<p class="empty-message">Fehler beim Laden der Assets</p>';
+      }
+    } catch (error) {
+      console.error('Error loading assets:', error);
+      assetGrid.innerHTML = '<p class="empty-message">Fehler beim Laden der Assets</p>';
+    }
+  }
+
+  // Render asset grid
+  function renderAssetGrid(assets) {
+    if (!assets || assets.length === 0) {
+      assetGrid.innerHTML = '<p class="empty-message">Keine Assets verfügbar</p>';
+      return;
+    }
+
+    assetGrid.innerHTML = assets.map(filename => {
+      const name = filename.replace(/\.[^.]+$/, '');
+      return `
+        <label class="asset-item">
+          <input type="checkbox" name="footerAssets" value="${filename}">
+          <img src="/assets/${filename}" alt="${name}">
+          <span class="asset-name">${name}</span>
+        </label>
+      `;
+    }).join('');
+  }
+
   // Render history list
   function renderHistory(history) {
     if (!history || history.length === 0) {

public/style.css

@@ -235,12 +235,64 @@ button:disabled {
   background: none;
 }
 
-.empty-message {
+.empty-message,
+.loading-message {
   text-align: center;
   color: #999;
   padding: 40px 20px;
 }
 
+/* Asset Grid */
+.asset-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
+  gap: 10px;
+  padding: 10px;
+  background: #f9f9f9;
+  border: 1px solid #ddd;
+  border-radius: 4px;
+}
+
+.asset-item {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  padding: 8px;
+  border: 2px solid transparent;
+  border-radius: 4px;
+  cursor: pointer;
+  transition: all 0.15s ease;
+}
+
+.asset-item:hover {
+  background: #eee;
+}
+
+.asset-item img {
+  width: 40px;
+  height: 40px;
+  object-fit: contain;
+}
+
+.asset-item .asset-name {
+  font-size: 11px;
+  color: #666;
+  margin-top: 4px;
+  text-align: center;
+  word-break: break-all;
+}
+
+.asset-item:has(input:checked) {
+  border-color: #3498db;
+  background: #e7f3fd;
+}
+
+.asset-item input[type="checkbox"] {
+  position: absolute;
+  opacity: 0;
+  pointer-events: none;
+}
+
 @media (max-width: 900px) {
   .container {
     flex-direction: column;

src/mailer.js

@@ -15,23 +15,25 @@ const transporter = nodemailer.createTransport({
 });
 
 const FOOTER_NAME = process.env.MAIL_FOOTER_NAME || 'Joachim Hummel';
-const FOOTER_IMAGE = path.join(__dirname, '..', 'assets', 'homeicon.png');
 
-function getHtmlFooter() {
+function getHtmlFooter(assets) {
+  if (!assets || assets.length === 0) {
+    return '';
+  }
+
+  const icons = assets.map(filename => {
+    const cid = filename.replace(/\.[^.]+$/, '');
+    return `<img src="cid:${cid}" alt="${cid}" width="40" height="40" style="display:inline-block; margin-right:8px;"/>`;
+  }).join('');
+
   return `
     <br/><br/>
     <hr style="border: none; border-top: 1px solid #ddd; margin: 20px 0;"/>
-    <table cellpadding="0" cellspacing="0" style="font-family: Arial, sans-serif; font-size: 14px; color: #666;">
+    <div style="font-family: Arial, sans-serif; font-size: 14px; color: #666;">
-      <tr>
+      <div style="margin-bottom: 8px;">${icons}</div>
-        <td style="vertical-align: middle; padding-right: 10px;">
+      <strong>Absender</strong><br/>
-          <img src="cid:homeicon" alt="Home" width="40" height="40" style="display: block;"/>
+      ${FOOTER_NAME}
-        </td>
+    </div>
-        <td style="vertical-align: middle;">
-          <strong>Absender</strong><br/>
-          ${FOOTER_NAME}
-        </td>
-      </tr>
-    </table>
   `;
 }
 
@@ -40,17 +42,19 @@ function getTextFooter() {
 }
 
 async function sendMail(email) {
+  const footerAssets = email.footerAssets || [];
+
+  const attachments = footerAssets.map(filename => ({
+    filename,
+    path: path.join(__dirname, '..', 'assets', filename),
+    cid: filename.replace(/\.[^.]+$/, '')
+  }));
+
   const mailOptions = {
     from: `"${process.env.MAIL_FROM_NAME}" <${process.env.MAIL_FROM_EMAIL}>`,
     to: email.to,
     subject: email.subject,
-    attachments: [
+    attachments
-      {
-        filename: 'homeicon.png',
-        path: FOOTER_IMAGE,
-        cid: 'homeicon'
-      }
-    ]
   };
 
   if (email.cc) {
@@ -58,11 +62,10 @@ async function sendMail(email) {
   }
 
   if (email.isHtml) {
-    mailOptions.html = email.body + getHtmlFooter();
+    mailOptions.html = email.body + getHtmlFooter(footerAssets);
   } else {
     mailOptions.text = email.body + getTextFooter();
-    // Also send HTML version with footer for better display
+    mailOptions.html = `<pre style="font-family: inherit; white-space: pre-wrap;">${email.body}</pre>` + getHtmlFooter(footerAssets);
-    mailOptions.html = `<pre style="font-family: inherit; white-space: pre-wrap;">${email.body}</pre>` + getHtmlFooter();
   }
 
   const info = await transporter.sendMail(mailOptions);

src/server.js

@@ -1,6 +1,7 @@
 require('dotenv').config();
 
 const express = require('express');
+const fs = require('fs');
 const path = require('path');
 const db = require('./database');
 const mailer = require('./mailer');
@@ -11,6 +12,7 @@ const PORT = process.env.PORT || 3000;
 // Middleware
 app.use(express.json());
 app.use(express.static(path.join(__dirname, '..', 'public')));
+app.use('/assets', express.static(path.join(__dirname, '..', 'assets')));
 
 // Email validation helper
 function isValidEmail(email) {
@@ -20,9 +22,29 @@ function isValidEmail(email) {
 
 // API Routes
 
+// Get available assets
+app.get('/api/assets', (req, res) => {
+  const assetsDir = path.join(__dirname, '..', 'assets');
+  const allowedExtensions = ['.png', '.jpg', '.jpeg', '.gif', '.svg'];
+
+  try {
+    const files = fs.readdirSync(assetsDir);
+    const assets = files
+      .filter(file => {
+        const ext = path.extname(file).toLowerCase();
+        return allowedExtensions.includes(ext);
+      })
+      .sort();
+
+    res.json({ success: true, assets });
+  } catch (error) {
+    res.status(500).json({ success: false, error: error.message });
+  }
+});
+
 // Send email
 app.post('/api/send', async (req, res) => {
-  const { to, cc, subject, body, isHtml } = req.body;
+  const { to, cc, subject, body, isHtml, footerAssets } = req.body;
 
   // Validation
   if (!to || !subject || !body) {
@@ -46,7 +68,7 @@ app.post('/api/send', async (req, res) => {
     });
   }
 
-  const email = { to, cc, subject, body, isHtml: !!isHtml };
+  const email = { to, cc, subject, body, isHtml: !!isHtml, footerAssets: footerAssets || [] };
 
   try {
     const info = await mailer.sendMail(email);