amp-consent-blocking meta tag is required

[fjanevski]

What's the issue?

As mentioned in the documentation for blocking behaviour with amp-consent we can block components either by:

• adding the data-block-on-consent attribute to the AMP extension
• adding the amp-consent-blocking meta tag with the list of extensions to be blocked

On our pages we are using the data-block-on-consent attribute, but from recently we started to receive invalid amp pages with the following message: The tag 'meta name=amp-consent-blocking' is missing or incorrect, but required by 'amp-consent'.

How do we reproduce the issue?

In the AMP playground by adding amp-consent and one other component, i.e. amp-analytics.

What browsers are affected?

Checked on Chrome 85.0.4183.121

Which AMP version is affected?

Checked on version: 2009252320001

[micajuine-ho]

Hi @fjanevski could you provide a link to one of your pages where you're experiencing this issue?

[fjanevski]

hi @micajuine-ho this is one example: https://gutscheine.focus.de/angebote/winterschlussverkauf/amp.

After some investigation we discovered that the issue is not happening on the general amp-consent implementation, but is vendor specific. We are using ConsentManager and only when that implementation is in place we face the issue.

Structure with issue:

<amp-consent layout="nodisplay" id="consent-element" type="ConsentManager">
    <script type="application/json">
        {
            "clientConfig": {
                "id": <ID>,
                "params": ""
            }
        }
    </script>
</amp-consent>

Works with:

<amp-consent layout="nodisplay" id="consent-element">
    <script type="application/json">
        {
            "consents": {
                "consentmanager-consent": {
                    "checkConsentHref": "https://consentmanager.mgr.consensu.org/delivery/amp.php?id=<ID>&type=check",
                    "onUpdateHref": "https://consentmanager.mgr.consensu.org/delivery/amp.php?id=<ID>&type=update",
                    "promptUI": "consent-ui"
                }
            }
        }
    </script>
    <amp-iframe id="consent-ui" height="100" width="600" resizable
                sandbox="allow-scripts allow-forms allow-same-origin allow-top-navigation allow-top-navigation-by-user-activation"
                layout="responsive" frameborder="0"
                src="https://consentmanager.mgr.consensu.org/delivery/amp.php?id=<ID>&type=consent">
    </amp-iframe>
</amp-consent>

[micajuine-ho]

Hi @fjanevski

hi @micajuine-ho this is one example: https://gutscheine.focus.de/angebote/winterschlussverkauf/amp.

When I open this page, I do not see the The tag 'meta name=amp-consent-blocking' is missing or incorrect, but required by 'amp-consent'. error message. Am I missing something?

[fjanevski]

Hi @micajuine-ho, we switched back to the general amp-consent implementation because it was a critical for us. The issue can be reproduced only when using the ConsentManager as a type of CMP.

[micajuine-ho]

I still cannot reproduce this when I test locally using ConsentManager type. Can you share the amp-consent config that triggered this error?

[fjanevski]

this is the configuration we used:

<amp-consent layout="nodisplay" id="consent-element" type="ConsentManager">
    <script type="application/json">
        {
            "clientConfig": {
                "id": "18009",
                "params": ""
            }
        }
    </script>
</amp-consent>

I can see the issue in AMP playground as well for this configuration.

[micajuine-ho]

I see now. This behavior is intentional for amp-consent when using a CMP integration.

See this comment for more information on this: #17742 (comment).

In any case, I will update the documentation to make this more clear.