iframe in - rewrite results - Override the output of this field with custom text I'm trying to make a view for showing latest youtube videos in a block

I have a field called Youtube Video ID (Plain text) where I Drupal 8 stores the ID of the video...

I'm using the option of the field "Override the output of this field with custom text" in REWRITE RESULTS...

I'm doing something like this:

&lt;div class='embed-container-youtube'&gt;
&lt;iframe src='http://www.youtube.com/embed/{{ field_id_video_de_youtube__value }}' frameborder='0' allowfullscreen&gt;&lt;/iframe&gt;
&lt;/div&gt;


Like you can see.. I'm using that mark up to show a youtube video.. taking the value of the field.... 

the problem is that Drupal is cleaning the iframe mark up.. I think for security...

this is how Drupal render it in the website

&lt;div class="embed-container-youtube"&gt;

&lt;/div&gt;


When you configure the content type you can see a note:

Allowed HTML tags: &lt;a&gt; &lt;b&gt; &lt;big&gt; &lt;code&gt; &lt;del&gt; &lt;em&gt; &lt;i&gt; &lt;ins&gt; &lt;pre&gt; &lt;q&gt; &lt;small&gt; &lt;span&gt; &lt;strong&gt; &lt;sub&gt; &lt;sup&gt; &lt;tt&gt; &lt;ol&gt; &lt;ul&gt; &lt;li&gt; &lt;p&gt; &lt;br&gt; &lt;img&gt;
This field supports tokens.


how can I add more allowed tags?

How can I allow that HTML tag for this view?
¡Thanks!
I have been wrestling with this as well but my users want to embed google docs.  Same concept though.

I figured out the solution and it's not super complicated.  You you just need to create a 'Field Template' in the theme. 

This video covers the concept with 'Node Template' but you can easily apply it to the field template.

Drupal 8 Theming - Part 11 - Displaying Fields
https://www.youtube.com/watch?v=fQ6Ypik_jsE