Empty Coalesce plugin for Craft CMS 3.x

Empty Coalesce adds the ??? operator to Twig that will return the first thing that is defined, not null, and not empty.

Requirements

This plugin requires Craft CMS 3.0.0 or later.

Installation

To install the plugin, follow these instructions.

Open your terminal and go to your Craft project:
```
 cd /path/to/project
```

Then tell Composer to load the plugin:

 composer require nystudio107/craft-emptycoalesce

In the Control Panel, go to Settings → Plugins and click the “Install” button for Empty Coalesce.

You can also install Empty Coalesce via the Plugin Store in the Craft Control Panel.

Empty Coalesce Overview

Empty Coalesce adds the ??? operator to Twig that will return the first thing that is defined, not null, and not empty. This is particularly useful when you're dealing with a number of fallback/default values that may or may not exist, and may or may not be empty.

The ??? Empty Coalescing operator is similar to the ?? null coalescing operator, but also ignores empty strings ("") and empty arrays ([]) as well.

It's pretty common in Twig that you might want to do something like use an entry.description if it exists, and if not, use a category.description if it exists, and then finally fall back on using some default global.description.

The problem is that to code defensively, you want to make sure that all of these things are defined, not null, and also have a value. So you end up with something like:

{% if entry is defined and entry.description is defined and entry.description | length %}
    {% set description = entry.description %}
{% elseif category is defined and category.description is defined and category.description | length %}
    {% set description = category.description %}
{% else %}
    {% set description = global.description %}
{% endif %}

This gets quite verbose and quite tiresome quickly. There are other ways you can do something similar, such as using using the ?: ternary operator and the default filter, but this too gets a bit unwieldy.

You can use the null coalescing operator, which picks the first thing that is defined and not null:

{% set description = entry.description ?? category.description ?? global.description %}

But the problem here is it'll just pick the first thing that is defined and not null. So if entry.description is an empty string, it'll use that, which is rarely what you want.

Enter the Empty Coalescing operator, and it becomes:

{% set description = entry.description ??? category.description ??? global.description %}

Now the first thing that is defined, not null, and not empty will be what description is set to.

Nice. Simple. Readable. And most importantly, likely the result you're expecting.

Configuring Empty Coalesce

There's nothing to configure.

Using Empty Coalesce

Using the Empty Coalescing operator is simple; you can chain together as many variables as you like:

{% set choice = thingOne ??? thingTwo ??? thingThree ??? thingFour %}

The first thing that is defined, not null, and not empty will be what choise is set to. If nothing meets that criteria, then choice is set to null. For example:

{% set bar = null %}
{% set foo = '' %}
{% set baz = [] %}
{% set foobar = woof ??? bar ??? foo ??? baz ??? 'bark' %}
{{ foobar }}

This will output:

bark

...because:

woof is undefined
bar is null
foo is an empty string
baz is an empty array

Happy templating!

Empty Coalesce Roadmap

Some things to do, and ideas for potential features:

Submit a PR to the Twig project to get it into core

Brought to you by nystudio107