Add built-in support for Google AMP

[mboynes]

Ideally, from a developer's perspective, this should be implemented such that the developer would call:

do_action( 'ad_layers_render_amp_ad_unit', $slot );

And the ad would render as an <amp-ad> element. This would probably involve adding a checkbox to the ad layer UI to flag a layer as a "Google AMP Ad Layer" if the AMP plugin is active.

[davisshaver]

@mboynes Looking into this...

We have is_amp_endpoint() available.

What do you think about this approach?

/**
 * Get the code for a specific ad unit.
 * Should be implemented by all child classes.
 * Since $ad_server will be empty for child classes,
 * this will automatically do nothing if they choose not to implement it.
 *
 * @access public
 */
public function get_ad_unit( $ad_unit, $echo = true ) {
  if ( function_exists( 'is_amp_endpoint' ) && is_amp_endpoint() ) {
    $is_amp = true;
  } else {
    $is_amp = false;
  }
  if ( ! empty( $this->ad_server ) ) {
    return $this->ad_server->get_ad_unit( $ad_unit, $echo, $is_amp );
  }
}

This way a site manager could use an existing sidebar containing ad units on their AMP pages.

[davisshaver]

cc @bcampeau for AMP connection

[mboynes]

@davisshaver I like that approach. In retrospect, I suppose we don't even need the UI changes, do we? Unless, I suppose, someone wanted to serve entirely different ad units on AMP pages, and in that case we'd need targeting options. I'm curious what you think about that.

Thanks!

[davisshaver]

@mboynes That is a great question... More I think about it, I expect we will need something new, but I'm just not sure yet.

If you're cool with the approach I can start testing it out in a branch. My hunch is that the unit size question may force our hand in adding UI elements. As well as the question about whether AMP pages need additional targeting capabilities.

[mboynes]

I'm absolutely on board with the approach, so go right ahead. Thanks for your help and input on this!

[anekola]

Is better AMP support on the roadmap still? Specifically looking for the output of ad_unit_js() and targeting_js(), which at the moment are dropped into a <script> tag that is stripped from AMP pages — so in practice, we are unable to target ads on AMP templates.