Fixing a YouTube regex in a replace filter

Question

I need to take the dominant YouTube URL schemas and convert them into a YouTube embed URL of the form:

https://www.youtube.com/embed/VIDEOID

I know there are technically loads of possible YouTube URL variants but I'm really only interested in:

1. https://www.youtube.com/watch?v=MvqY2NcBWI8
2. https://youtu.be/MvqY2NcBWI8

…where either of those could be extended with optional parameters.

So I'm doing this to extract the vidId, which works for 1:

{% set vidUrl = block.videoUrl %}
{% set vidId  = vidUrl|replace('/^http.*\\?v=([^\\&]+)(\\&.*)?$/', '$1') %}

…and then this for 2:

{% set vidId = vidId ? vidId : vidUrl|replace('/^http.*\\.be\\/([^\\?]+)(\\?.*)?$/', '$1') %}

…which doesn’t work.

And yet when I replace \\ with \ and test it in my text editor it does work.

This should capture the id up to the beginning of any query string…

([^\\?]+)

…and this should discard any parameters which follow…

(\\?.*)?$

Shouldn't it? What am I missing?

Answer 1

Doh! It was my ternary logic that was failing not the regex. I’m now doing this:

{% set vidUrl = block.videoUrl %}

{% if 'youtu' in vidUrl %}
    {# Check for an 'embed' URL which may need cleaning #}
    {% set vidId = 'embed' in vidUrl ? vidUrl|replace('/^http.*embed\\/([^\\?]+)(\\?.*)?$/', '$1') : null %}

    {# Check for a 'watch' URL which may need cleaning #}
    {% set vidId = 'watch' in vidUrl ? vidUrl|replace('/^http.*\\?v=([^\\&]+)(\\&.*)?$/', '$1') : vidId %}

    {# Check for a 'youtu.be' URL which may need cleaning #}
    {% set vidId = '.be/' in vidUrl ? vidUrl|replace('/^http.*\\.be\\/([^\\?]+)(\\?.*)?$/', '$1') : vidId %}

    {% set srcUrl = vidId ? "https://www.youtube.com/embed/#{vidId}" : null %}
{% endif %}

{% if srcUrl %}
    {# Write the iframe #}
{% else %}
    {# Write some help for logged in CMS folks #}
{% endif %}