在循环中渲染项目，为每个项目提供自己的<li>：

<ul class="items"
        data-index="{{ form.items|length > 0 ? form.items|last.vars.name + 1 : 0 }}"
        data-prototype="{{ form_widget(form.items.vars.prototype)|e('html_attr') }}">
        {% for itemForm in form.items %}
            <li class="item">
                {{ form_label(itemForm) }}
                {{ form_widget(itemForm) }}
                {{ form_errors(itemForm) }}
            </li>
        {% endfor %}
    </ul>

然后创建一个JavaScript函数，该函数将删除链接添加到给定项：

const addItemFormDeleteLink = (item) => {
        const removeLink = document.createElement('a');
        removeLink.href = '#';
        removeLink.innerText = 'Remove';
        removeLink.classList.add('remove');

        item.appendChild(removeLink);

        removeLink.addEventListener('click', (e) => {
            e.preventDefault();
            item.remove();
        })
    }

并使用此选项将删除链接添加到页面上的现有项目：

document
        .querySelectorAll('ul.items li')
        .forEach((tag) => {
            addItemFormDeleteLink(tag)
        })

在addFormToCollection中：

const addFormToCollection = (e) => {
        const collectionHolder = document.querySelector('.' + e.currentTarget.dataset.collectionHolderClass);

        const item = document.createElement('li');

        item.innerHTML = collectionHolder
            .dataset
            .prototype
            .replace(
            /__name__/g,
            collectionHolder.dataset.index
            );

        collectionHolder.appendChild(item);
        collectionHolder.dataset.index++;

        // add a delete link to the new form
        addItemFormDeleteLink(item);
    }

另请参阅：https://symfony.com/doc/current/form/form_collections.html#allowing-tags-to-be-removed