如何在Twig中访问实体属性（使用OpenClassroom上的Winzou Symfony2教程）？
类别是我的班级广告的一个属性，其中包含我的所有广告。我只想在没有广告实体的情况下显示错误消息。
这是我的手风琴，列出＆＃34;广告＆＃34;来自我的广告实体。一个手风琴用于incident类别，另一个用于类别general。
<div class="well">
<div class="accordion" id="accordion2">
<div class="accordion-group">
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion2" href="#collapseGen">
<h3><i class="icon-chevron-right"></i> Incidents</h3>
</a>
</div>
<div id="collapseGen" class="accordion-body collapse">
<div class="accordion-inner">
<div class="accordion" id="accordion4">
{% for advert in listAdverts %}
{% if advert.category == "incident" %}
<div class="accordion-group">
<div class="accordion-heading decalage">
<a href="{{ path('info_view', {'id': advert.id}) }}">
<h3 class="{{ advert.category }}">{{ advert.title }}</h3>
</a>
<div>
<span>{{ advert.content|truncate(100, true, '...')|raw }}</span>
</div>
<div>
{% if (advert.UpdatedAt is empty) %}
<i>Créé par {{ advert.author }}, le {{ advert.date|date('d/m/Y') }}
à {{ advert.date|date('H:i') }}</i>
{% else %}
<i>Modifié par {{ advert.author }},
le {{ advert.updatedAt|date('d/m/Y') }}
à {{ advert.updatedAt|date('H:i') }}</i>
{% endif %}
</div>
<div>{% if advert.readers is not empty %}
<i>Vu par :
{% for reader in advert.readers %}
{{ reader.username }},
{% endfor %}
{% endif %}</i>
</div>
<br>
<div>
{% if is_granted("IS_AUTHENTICATED_FULLY") %}
<p>
<a href="{{ path('info_edit', {'id': advert.id}) }}"
class="btn btn-default">
<i class="fa fa-pencil-square-o" aria-hidden="true"></i>
Modifier
</a>
<a href="#myModal{{ advert.id }}" role="button" class="btn btn-danger"
data-toggle="modal">
<i class="fa fa-trash-o" aria-hidden="true"></i>
Supprimer
</a>
</p>
<div id="myModal{{ advert.id }}" class="modal hide fade">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal"
aria-hidden="true">×</button>
<h3>Suppression annonce "{{ advert.title }}"</h3>
</div>
<div class="modal-body">
<p>Voulez-vous vraiment supprimer l'annonce : "{{ advert.title }}" ? </p>
</div>
<div class="modal-footer parente">
<div><a href="#" class="btn" data-dismiss="modal">Annuler</a></div>
<div>
<form class="nomargin"
action="{{ path('info_delete', {'id': advert.id}) }}"
method="post">
<input type="submit" value="Supprimer"
class="btn btn-danger"/>{{ form_rest(form) }}
</form>
</div>
</div>
</div>
{% endif %}
</div>
</div>
</div>
{# HERE I DONT KNOW HOW TO DO IT #}
{% else %} No Advert !
{% endif %}
{% endfor %}
</div>
</div>
</div>
</div>
<div class="accordion-group">
<div class="accordion-heading">
<a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion2" href="#collapseCo">
<h3><i class="icon-chevron-right"></i> Général</h3>
</a>
</div>
<div id="collapseCo" class="accordion-body collapse">
<div class="accordion-inner">
<div class="accordion" id="accordion4">
{% for advert in listAdverts %}
{% if advert.category == "general" %}
<div class="accordion-group">
<div class="accordion-heading decalage">
<div class="accordion-heading">
<a href="{{ path('info_view', {'id': advert.id}) }}">
<h3 class="{{ advert.category }}">{{ advert.title }}</h3>
</a>
<span>{{ advert.content|truncate(100, true, '...')|raw }}</span>
<div>
{% if (advert.UpdatedAt is empty) %}
<i>Créé par {{ advert.author }}, le {{ advert.date|date('d/m/Y') }}
à {{ advert.date|date('H:i') }}</i>
{% else %}
<i>Modifié par {{ advert.author }},
le {{ advert.updatedAt|date('d/m/Y') }}
à {{ advert.updatedAt|date('H:i') }}</i>
{% endif %}
</div>
<div>{% if advert.readers is not empty %}
<i>Vu par :
{% for reader in advert.readers %}
{{ reader.username }},
{% endfor %}
{% endif %}</i>
</div>
<br>
<div>
{% if is_granted("IS_AUTHENTICATED_FULLY") %}
<p>
<a href="{{ path('info_edit', {'id': advert.id}) }}"
class="btn btn-default">
<i class="fa fa-pencil-square-o" aria-hidden="true"></i>
Modifier
</a>
<a href="#myModal{{ advert.id }}" role="button" class="btn btn-danger"
data-toggle="modal">
<i class="fa fa-trash-o" aria-hidden="true"></i>
Supprimer
</a>
</p>
<div id="myModal{{ advert.id }}" class="modal hide fade">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal"
aria-hidden="true">×</button>
<h3>Suppression annonce "{{ advert.title }}"</h3>
</div>
<div class="modal-body">
<p>Voulez-vous vraiment supprimer l'annonce : "{{ advert.title }}" ? </p>
</div>
<div class="modal-footer parente">
<div><a href="#" class="btn" data-dismiss="modal">Annuler</a></div>
<div>
<form class="nomargin"
action="{{ path('info_delete', {'id': advert.id}) }}"
method="post">
<input type="submit" value="Supprimer"
class="btn btn-danger"/>{{ form_rest(form) }}
</form>
</div>
</div>
</div>
{% endif %}
</div>
</div>
</div>
</div>
{% endif %}
{% endfor %}
</div>
</div>
</div>
</div>
</div>
</div>
{% endblock %}
我的错误讯息＆＃34;没有广告！＆＃34;没有出现..
编辑：根据Mitchel的回答，我试过这个：
{% endif %}
{% else %}<li>No Adverts</li>
{% endfor %}
我不知道为什么当一个广告属于另一个类别时它不起作用...
{% for advert in listAdverts if advert.category == "incident" %}
{% if listAdverts is empty%}
<li>No Adverts</li>
{% endif %}
{% endfor %}
该代码不起作用。
答案 0 :(得分：1)
我不确定你的问题，但如果是这样，你可以根据文件尝试这样的事情：
{% for user in users %}
<li>{{ user.username|e }}</li>
{% else %}
<li><em>no user found</em></li>
{% endfor %}
答案 1 :(得分：0)
在Twig中，for语句可以包含关联的else。它基本上意味着如果for没有结果，则使用else。您应该将{% endif %}放在{% else %}之前，它应该有效。