Question on calling body_classes in Twig

In the Gantry5 modular.html.twig template it contain the following code:

{% block content %}
{{ page.content|raw }}
{% for module in page.collection() %}
    <div id="{{ macro.pageLinkName(module.menu) }}">
    {{ module.content|raw }}
{% endfor %}

</div>
{% endblock %}

I want to modify it so it will use the body_classes tag on a modular page. In some themes this seems to work automatically like in the bootstrap4 theme. The code is almost identical.

{% block content %}
{{ page.content|raw }}

{% for module in page.collection() %}
    <div class="modular-anchor" id="{{ macro.pageLinkName(module.menu) }}"></div>
    {{ module.content|raw }}
{% endfor %}
{% endblock %}

I thought changing the Gantry5 template to use the following would work but it refuses to recognize the page.header.body_classes tag.

<div class="{{ page.header.body_classes }}" id="{{ macro.pageLinkName(module.menu) }}"></div>

Is there a different method to adding the body_classes tag to the modular templates? If I manually add class="myClsss" instead of the body_classess tag it works.

Thanks.

@tom0360, Maybe I'm just confused, but you show the Gantry template to be:

{% for module in page.collection() %}
    <div id="{{ macro.pageLinkName(module.menu) }}">
    {{ module.content|raw }}
{% endfor %}

and you changed the code inside the loop to:

<div class="{{ page.header.body_classes }}" id="{{ macro.pageLinkName(module.menu) }}"></div>

Correct?

If so, shouldn't it be referencing module instead of page inside the loop?

  <div class="{{ module.header.body_classes }}" id="{{ macro.pageLinkName(module.menu) }}"></div>

Else if your real code is correct, are you sure the frontmatter of the module does indeed contain a value for body_classes. Did you do a dump of module.header to see if body_classes does exist and does have a value?

@pamtbaau,

You are correct. I am just winging it and am not familiar with actually works. I thought I had used the page.header.body_classes on another modular template when I had tried this before but I went and looked at the theme and it is using Bootstrap4 which means it was already working so my changes probably did nothing. lol

Thank you for the help : )

@pamtbaau,

Sorry, I was testing it out. Yes, it does appear to work correctly now, Thank you.