Check for freemarker variable set in child in the base template

I am using freemarker to render my frontend.

This is an extract of my base.ftlh that I use in my pages as a layout. A lot of pages have a header in a similar style therefore they can set the banner icon and the texts for themselves. However, some pages should not have this header, and I want to define a variable like just a boolean header to only render this part if it is set to true, which should be the default.

<#-- Application Main Content - Start -->
<div class="content-grid">
    <#if header!true>
        <div class="section-banner">
            <#if title_banner??>
                <img class="section-banner-icon" src="<@title_banner />" alt="badges-icon">
            </#if>
            <#if title??>
                <p class="section-banner-title"><@title /></p>
            </#if>
            <#if subtitle??>
                <p class="section-banner-text"><@subtitle /></p>
            </#if>
        </div>
    </#if>
    <#if page_body??>
        <@page_body/>
    </#if>
</div>

This is the top of one of my pages profile.ftlh where I want to use the base and tell it to not use the header:

<#include  "/base.ftlh">

<#macro page_title>
    Profil-Suche
</#macro>

<#assign header = false>

<#macro page_body>
    ...

However, this does not work and my header variable I set in my profile.ftlh is completely ignored... How can I achieve this? I'd rather not put the header manually in every page that needs it, I'd prefer it to stay in the base.

The problem is that you are including base.ftl before setting the header variable. Instead, do that #include as the very last thing.

Note that like in many languages, subroutines (defined with #function/#macro) can be called before reaching the defining statements, so that's why that worked. But assignments can't do such a trick. So it's just cleaner if you do everything before including base.ftl.