Allow Editor to specify whether Event links should open in in blank tab

[brylie]

Currently, Event website links open in a blank tab. However, the Editor may want to selectively open some links in a new tab, such as external links, while others would open in the same tab (e.g., internal links).

ℹ️ see a possible solution in a comment below: #368 (comment)

The Wagtail RichText editor doesn't allow users to specify a target when adding URLs but may support that feature at a later point: wagtail/wagtail#8150
wagtail/wagtail#1167

Task

• determine the priority of supporting the target attribute for Event-related links
• decide on a possible solution, such as adding a repeating field group for Event website(s) and a target attribute

[brylie]

We might use a bit of JavaScript to scan all links on a page when it renders and set the target link to blank for external links.

// Work-in-progress based on
// https://github.com/wagtail/wagtail/issues/1167#issuecomment-1072345927
$(document).ready(function(){
    $('a[href^="http://westernfriend.org"]').attr('target', '_blank');
    $('a[href^="http://"]').attr('rel', 'nofollow noopener');
    $('a[href^="https://"]').attr('target', '_blank');
    $('a[href^="https://"]').attr('rel', 'nofollow noopener');
    });

[brylie]

There is a solution to this issue that was suggested in the Wagtail GitHub issue: wagtail/wagtail#1167 (comment)

from django.utils.html import escape
from wagtail.core import hooks

def external_link_handler(attrs):
    href = attrs["href"]
    return '<a href="%s" target="_blank" rel="noopener nofollower">' % escape(href)

@hooks.register('register_rich_text_features')
def register_external_link(features):
    features.register_link_type('external', external_link_handler)

[marycklein]

I think this flexibility is something I would like to have site-wide, not just for "events."