source: src/main/resources/templates/add_product.html

<th:block xmlns:th="http://www.thymeleaf.org">
  <section class="jumbotron text-center">
    <div class="container">
      <h1 class="jumbotron-heading">FMO</h1>
      <h2 class="jumbotron-heading">Food Market Online</h2>
    </div>
  </section>

  <div class="container">
    <div class="row">
      <div class="col-md-5">
        <form action="/products/add" method="POST">
          <input id="id" type="hidden" name="id" th:value="(${product} != null ? ${product.getIdProdukt()} : '')">
          <div class="form-group">
            <label for="name">Product name</label>
            <input type="text"
                   class="form-control"
                   id="name"
                   name="name"
                   th:value="(${product} != null ? ${product.getIme()} : '')"
                   required
                   placeholder="Enter product name">
          </div>
          <div class="form-group">
            <label for="price">Price</label>
            <input type="text"
                   class="form-control"
                   id="price"
                   name="price"
                   required
                   th:value="(${price?.getIznos()} )"
                   placeholder="Price">
          </div>
          <div class="form-group">
            <label for="Description">Description</label>
            <input type="text"
                   class="form-control"
                   id="description"
                   name="description"
                   th:value="(${product} != null ? ${product.getOpis()} : '')"
                   placeholder="Description">
          </div>
          <div class="form-group">
            <label>Category</label>
            <select name="category" class="form-control">
              <option th:if="${chosen} != null"
                      th:selected="${chosen.getIdKategorija() != null &&
                                chosen.getIdKategorija() == cat.getIdKategorija()}"
                      th:each="cat : ${categories}"
                      th:value="${cat.getIdKategorija()}"
                      th:text="${cat.getIme()}">
              </option>
              <option th:if="${chosen} == null"
                      th:each="cat : ${categories}"
                      th:value="${cat.getIdKategorija()}"
                      th:text="${cat.getIme()}">
              </option>
            </select>
          </div>
          <div class="form-group">
            <label>Date from</label>
           <input type="date"
                           class="form-control"
                           id="date"
                           name="date"
                           th:value="${price?.getCenaOd()} ?: null"
                           required>
          </div>
          <div class="form-group">
            <label>Date to</label>
            <input type="date"
                   class="form-control"
                   id="dateTo"
                   name="dateTo"
                   th:value="${price?.getCenaDo() }">
          </div>

          <button id="submit" type="submit" class="btn btn-primary">Submit</button>
          <a type="button" class="btn btn-primary" href="/products">Back</a>
        </form>
      </div>
    </div>
  </div>


</th:block>