YouTube urls with `/embed/` in the url fail to embed

Issue Summary

Using an Embed block in a streamfield, we are able to embed videos from youtube.com like this https://youtu.be/2MW6CrxScLk or like this https://www.youtube.com/watch?v=2MW6CrxScLk but not like this https://youtube.com/embed/2MW6CrxScLk

Steps to Reproduce

Grab a youtube url by clicking on a link that says “Embed”.

Technical details

• Python version: 3.4
• Django version: 1.11.
• Wagtail version: 1.13.1
• Browser version: Chrome 62 (but it’s a backend thing)

[lb-]

I have a working version (needs tests/docs before I put in a PR) of the templates idea.

See the revised oembed code here: https://github.com/lb-/wagtail/blob/4127_embed_youtube_url/wagtail/embeds/finders/oembed.py

A working template that here: https://github.com/lb-/wagtail/blob/e7b8315f80a68b7b07ff83dce43ee20fe5b48f52/wagtail/embeds/oembed_providers.py#L29-L31

Would love some feedback if it is worth adding this feature, happy to add tests / document this correctly.

[cjoshmartin]

Hello y’all I was looking for answer for days but I found it here: https://docs.wagtail.org/en/stable/topics/writing_templates.html#responsive-embeds

for some reason it did not show up on google 🤔

Short of it is:

1. in your base settings file add this WAGTAILEMBEDS_RESPONSIVE_HTML = True
2. In the template file you are using the embed with add these styles:

.responsive-object {
    position: relative;
}

.responsive-object iframe,
.responsive-object object,
.responsive-object embed {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

and BOOM responsive embeddeds