What is the best way to pass a block from a layout to a parent layout?

[nhoizey]

I'm using Nunjucks layouts, and the layout attribute in Front Matter for layout chaining, so that a page.njk layout uses a base.njk layout.

As I read it, the Addendum about existing Templating features states that “Eleventy’s layout system exists a layer above Nunjucks' Template Inheritance exposed with {% extends %}“.

So I thought {% extends %} was implicit when using layout chaining, but a {% block %} defined in my page.njk layout never arrives into base.njk.

I tried to add an explicit {% extends %} like I saw in Phil Hawksworth's code, but I get the base.njk included twice, kind of recursively

If I remove the layout attribute from the Front Matter of the page.njk layout, its content doesn't arrive into base.njk anymore.

I must be missing something obvious, so how is it supposed to work?

Thanks

[philhawksworth]

If I recall correctly, in Eleventy, Nunjucks happily passes content through to the specified layout without using extends if you are just populating the content. When you have multiple blocks that you wish to pass through to a layout, then you need to use extends.

At least, this seems to work for me™

I'm struggling to find the documentation I thought had lead me to that conclusion.

[nhoizey]

@philhawksworth what I see in your aforementioned post.njk layout is that you have an explicit {% extends … %}, but no Front Matter and no content outside {% block … %}s.

So it looks like it's either one or the other:

• Eleventy layout chaining with Front Matter layout property OR
• an {% extends … %} and a series of {% block … %}s

The later seems to be the best (or even the only way) to "pass" an HTML fragment (a "block") to the parent (extended) layout.

[nhoizey]

Oh, looks like @zachleat already answered this is "by design": https://github.com/11ty/eleventy/issues/834#issuecomment-569474008

That's not why I understood when reading the Addendum about existing Templating features, maybe we could rephrase it.

[philhawksworth]

Aha. Yeah, there it is. Nice one @nhoizey!

[rikschennink]

Default support for blocks would be super nice.

In the mean time, I've set up these tags to recreate similar functionality, maybe it's of help to someone else.

module.exports = function (eleventyConfig) {

    const layoutblocks = [];

    eleventyConfig.addShortcode('renderlayoutblock', function(name) {
        return (this.page.layoutblock || {})[name];
    });

    eleventyConfig.addPairedShortcode('layoutblock', (content, name) {
        if (!this.page.layoutblock) this.page.layoutblock = {};
        this.page.layoutblock[name] = content;
    });

}

Define a layoutblock block with name foo like this in the layout template:

{% renderlayoutblock 'foo' %}

Set the contents of layoutblock with name foo in a document like this:

{% layoutblock 'foo' %}
Hello World
{% endlayoutblock %}

[gluecksmensch]

@rikschennink Thanks for the suggestion! this.page.layoutblock doesn't work because this.page is undefined. And the variable const layoutblocks = [] is obsolete as it's not used. But this worked for me:

module.exports = function (eleventyConfig) {

    eleventyConfig.addShortcode('renderlayoutblock', function(name) {
        return (this.layoutblock || {})[name];
    });

    eleventyConfig.addPairedShortcode('layoutblock', (content, name) {
        if (!this.layoutblock) this.layoutblock = {};
        this.layoutblock[name] = content;
    });
}

[rikschennink]

@gluecksmensch good one.

Previous iteration I stored data in const layoutblocks = [] but that didn't work ( obviously :D ) forgot to remove.

I guess with my templates page is defined, didn't realise this wasn't always the case, nice improvement 👍

[nhoizey]

@rikschennink @gluecksmensch as we showed before in the thread, you can use Nunjucks' {% extend … %} directly, without additional shortcode, but you can't use Eleventy's layout Front Matter with it.

I do this here for example: https://github.com/nhoizey/precious-prana.com/blob/master/src/_includes/layouts/evenement.njk#L2

And here's the base.njk layout definig blocks: https://github.com/nhoizey/precious-prana.com/blob/master/src/_includes/layouts/base.njk

[surferjeff]

11ty newbie here. I hit this same issue, and followed the pattern from @nhoizey, however all the block sections are missing in the generated html.

index.njk:

{% extends "layout.njk" %}

{% block title %} Home page in HTML {% endblock %}

{% block header %}
    <meta charset="utf-8" />
{% endblock %}

{% block content %}
<p>
    Welcome to my 11ty website.
</p>

{% include "footer.njk" %}

{% endblock %}

_includes/layout.njk

<!DOCTYPE html>
<html>
<head>
    <title>{{ title }}</title>
    <style>
        .active { background: yellow }
    </style>
    {{ header | safe }}
</head>
<body>
    <div>
        <a href="/" class="{{ 'active' if '/' == page.url }}">Home</a>
        <a href="/README" class="{{ 'active' if '/README/' == page.url }}">README</a>
    </div>
    {{ content | safe }}
</body>
</html>

Generated index.html:

<!DOCTYPE html>
<html>
<head>
    <title></title>
    <style>
        .active { background: yellow }
    </style>
    
</head>
<body>
    <div>
        <a href="/" class="active">Home</a>
        <a href="/README" class="">README</a>
    </div>
    
</body>
</html>

Full source code is here: https://github.com/surferjeff/scratch/tree/main/hello-11ty

[pdehaan]

@surferjeff Looking at @nhoizey's repo, I think you need to define your blocks in your _includes/layout.njk file, similar to this:

https://github.com/nhoizey/precious-prana.com/blob/83380d5a9e489d1e4c25c4077c68ac2461bc16a4/src/_includes/layouts/base.njk?rgh-link-date=2021-02-22T09%3A38%3A39Z#L27-L30

-    <title>{{ title }}</title>
+    {% block title %}
+    <title>{{ title }}</title>
+    <meta property="og:title" content="{{ title }}" />
+    {% endblock %}

Then you can either set the title via front matter, or override it by explicitly setting the {% block title %} block:

{% block title %}
<title>Precious Prana, faire pétiller</title>
<meta property="og:title" content="Precious Prana, faire pétiller" />
{% endblock %}

(see https://github.com/nhoizey/precious-prana.com/blob/f7edfa0b1da0e36e9c52115dd2228a6e9629e899/src/_includes/layouts/homepage.njk#L3-L6)

[pdehaan]

@surferjeff Try something like this:

<!DOCTYPE html>
<html>
<head>
    {% block title %}
    <title>{{ title }}</title>
    {% endblock %}
    <style>
        .active { background: yellow }
    </style>
    {% block header %}
    {{ header | safe }}
    {% endblock %}
</head>
<body>
    <div>
        <a href="/" class="{{ 'active' if '/' == page.url }}">Home</a>
        <a href="/README" class="{{ 'active' if '/README/' == page.url }}">README</a>
    </div>
    {% block content %}
    {{ content | safe }}
    {% endblock %}
</body>
</html>

And…

{% extends "layout.njk" %}

{% block title %}
    <title>Home page in HTML</title>
{% endblock %}

{% block header %}
    <meta charset="utf-8" />
{% endblock %}

{% block content %}
    <p>Welcome to my 11ty website.</p>
    {% include "footer.njk" %}
{% endblock %}

Or set the title via front matter, if you don't want to set the <title> tags and override other stuff:

---
title: Override title
---

{% extends "layout.njk" %}

{% block header %}
    <meta charset="utf-8" />
{% endblock %}

{% block content %}
    <p>Welcome to my 11ty website.</p>
    {% include "footer.njk" %}
{% endblock %}

[surferjeff]

Ah, I see now. Thanks for the quick replies!