Do not add advanced prop on submit (DenverCoder1#436)

Co-authored-by: DenverCoder1 <[email protected]>
Fixes DenverCoder1#432

Author: timagixe

src/demo/index.php

@@ -106,7 +106,7 @@ function gtag() {
                     <option>false</option>
                     <option>true</option>
                 </select>
-                
+
                 <label for="border_radius">Border Radius</label>
                 <input class="param" type="number" id="border_radius" name="border_radius" placeholder="4.5" value="4.5" step="0.1">
 
@@ -146,13 +146,13 @@ function gtag() {
                                 <option><?php echo $option; ?></option>
                             <?php endforeach; ?>
                         </select>
-                        <button class="plus btn" onclick="return preview.addProperty();">+</button>
+                        <button class="plus btn" type="button" onclick="return preview.addProperty()">+</button>
                     </div>
-                    <button class="btn" type="button" onclick='return preview.exportPhp()'>Export to PHP</button>
+                    <button class="btn" type="button" onclick="return preview.exportPhp()">Export to PHP</button>
                     <textarea id="exportedPhp" hidden></textarea>
                 </details>
 
-                <input class="btn" type="submit" value="Open Permalink">
+                <button class="btn" type="submit">Open Permalink</button>
             </form>
         </div>
 
@@ -192,4 +192,4 @@ function gtag() {
     </a>
 </body>
 
-</html>
+</html>

src/demo/js/script.js

@@ -80,6 +80,7 @@ const preview = {
       const minus = document.createElement("button");
       minus.className = "minus btn";
       minus.setAttribute("onclick", "return preview.removeProperty(this.getAttribute('data-property'));");
+      minus.setAttribute("type", "button");
       minus.innerText = "−";
       minus.setAttribute("data-property", propertyName);
       // add elements