Wagtail External Links

What is it?

A template tag that checks if a link is internal of external.

Why?

It's a bit specific, but it's generally bad form to make all external links open in a new tab. So this gives the developers a bit more control on how and where to check for external links. It's also useful to return True or False here so it can be used for url link targets and icons.

How does it work?

By checking if link values passed in exsist in a list of domains specified as internal only. Define a list if "internal domains" in settings. These are links that you would always want to be internal, anything not in this list will be counted as external. It also works with firstof for mutiple values.

Example

{% is_external 'https://bbc.co.uk' %} would return True
{% is_external '' '' %} would return False (no links)
{% is_external 'https://yoursite.com' 'https://bbc.co.uk' %}   would return False

Configuration

After installing add to your INSTALLED_APPS

INSTALLED_APPS = [
    ...
    'wagtail_external_links',
]

Set what domains are going to always be internal by specifying in settings:

WAGTAIL_EXTERNAL_LINKS_CONFIG = {
    "internal_domains": [
        'example.com',
        'yoursite.com',
    ]
}

To use in a template, first load the template tag by adding the following to your template

{% load wagtail_external_link_tags %}

Usage E.G:
{% is_external 'https://bbc.co.uk' %}

Usage E.G:
{% is_external value.href href as is_external %}
<a class="link {% if is_external %}link--external{% endif %}" {% if is_external %} target="_blank" {% endif %} href="{% firstof value.href href %}">

What this doesn't handle...

Rich text links.

External links added in rich text need extra attention, add the following to a wagtail_hooks file

class TargetBlankExternalLinkHandler(LinkHandler):
    identifier = "external"

    @classmethod
    def expand_db_attributes(cls, attrs):
        href = attrs["href"]
        target = 'target="_blank"' if is_external(href) else ""
        _class = 'class="external-link"' if is_external(href) else ""
        rel = 'rel="noopener"' if is_external(href) else ""
        return f'<a href="{escape(href)}"{target} {_class} {rel}>'


@hooks.register("register_rich_text_features")
def register_external_link(features):
    features.register_link_type(TargetBlankExternalLinkHandler)