symfony-2.5 - 如何在树枝文件中给出调用博客的条件？

Question

这是我的 twig 文件，我想用 'if' 条件调用一个特定的博客，但不知道如何放置它。我参考了一些网站，但它说你只能包含或嵌入整个 twig 文件。

{% extends "AtplUserBundle::layout.html.twig" %}

{% block title "Usability Instructions" %}

{% block body %}

{% block nav %}

<nav class="navbar navbar-custom navbar-fixed-top inner-nav" role="navigation">
    <div class="container">
        <div class="navbar-header page-scroll">
            <a class="navbar-brand" href="/app_dev.php">
                <img src="{{asset('bundles/wpapp/images/logo.png')}}">
            </a>
        </div>

        <div class="fr">
            <div class="callnumber">307 509 0688</div>
            <div class="clear-fr"></div>
            <div class="btnpart">
                <a href="#" class="signout-btn">Sign Out</a>
                <span></span>
            </div>
            <!-- Collect the nav links, forms, and other content for toggling -->
        </div>

    </div>
    <!-- /.container -->
</nav>

{% endblock %}

{% block content %}

 {% block main %}

<section class="offline-player">
    <div class="container">
        {#<div class="col-md-8">
            <h1 class="h1">Edit Business Description</h1>
            <h2>{{business_desc}}</h2>
        </div>#}
        <div class="row">
            <div class="heading">
                <h1>Usability Instructions<a href="/app_dev.php/dashboard" class="back-dash"><img src="{{asset('bundles/wpapp/images/icon_dashboard.png')}}">Back To Dashboard</a></h1>
            </div>
        </div>
        <div>
            {% if true %}

            {% endif %}
        </div>

    </div>
</section>
{% endblock %}

{% block footer %} 
<section id="footer" class="footer2">
    <div class="container text-center">
        <div class="col-md-12">
            <ul>
                <li><a href="#">Company</a></li>
                <li><a href="#">Service Agreement</a></li>
                <li><a href="#">Copyrights</a></li>
                <li><a href="#">Privacy</a></li>
                <li><a href="#">Compliance</a></li>
            </ul>
            <div class="text-center">
                <img src="{{asset('bundles/wpapp/images/footerimg.jpg')}}">
            </div>
        </div>
    </div>
</section>
    {% endblock %}

{% endblock %}

{% endblock %}