Mailchimp Block: Interests/SIGNUP merge field/AMP state hook

[jeffersonrabb]

Introduces a few new features to the Mailchimp block:

• Support for Audience Groups. These allow subscribers to be grouped based on their interests, which allows for superior communication and segmentation. Mailchimp charges by the subscriber, so it's more cost effective to maintain one list with multiple groups as opposed to creating separate groups for topics. Also, the WPCOM Mailchimp implementation currently supports only one list per site.
• Support for a SIGNUP merge field which is used to know where a subscriber came from.
• AMP State. After a successful signup AMP state will be updated. This is needed by the Newspack Pop-ups block, to enable the logic that suppresses pop-ups if the current user has already subscribed.

Preparation

• This PR must be tested with D35074-code.
• You will need a WPCOM sandbox sandboxed for Jetpack development, since this PR uses Client::wpcom_json_api_request_as_blog()
• You will need a Mailchimp account.
• Local Jetpack instance will need to have the AMP plugin installed and in Transitional Mode.
• Testing site will need a secure public URL.

Is this a new feature or does it add/remove features to an existing part of Jetpack?

Discussion here: p1HpG7-7WS-p2

Testing instructions:

• Create a Mailchimp account (if you don't have one already).
• Create a List, and add some Groups. Documentation here: https://mailchimp.com/help/send-groups-audience/
• [UPDATED 11.20] Set up a SIGNUP field following the instructions here. The name of the field must be "SIGNUP"
• Apply D35074-code to WPCOM Sandbox, and be sure JETPACK__SANDBOX_DOMAIN is configured for Jetpack development.
• Add Mailchimp block to a post, follow flow to connect the Mailchimp account and select the correct list.
• In the Mailchimp block sidebar, verify you see a "Mailchimp Groups" pane with a checkbox for every group created in Mailchimp dashboard.
• In Mailchimp block sidebar verify there is a "Merge Fields" pane with a single "Signup Location" field.
• In "Mailchimp Groups" select one or more groups.
• Set Signup location to an arbitrary value, e.g. "My Blog"
• Publish the post and view the published page.
• In a non-AMP request, subscribe. Verify the email appears on the list in the Mailchimp dashboard and that it is in the correct groups and has the correct SIGNUP value.
• In an AMP request (append ?amp to the URL), subscribe. Verify the email appears on the list in the Mailchimp dashboard and that it is in the correct groups and has the correct SIGNUP value.
• To verify the AMP state elements, append ?amp#development=1 to the end of the URL and reload. In the console you should be able to execute AMP.printState() and get a valid response. Subscribe with a new email address. After success, execute AMP.printState() again. Verify the state contains mailing_list_status: "subscribed" and mailing_list_email: {SUBSCRIBED_EMAIL_ADDRESS}

Proposed changelog entry for your changes:

• Support for Mailchimp Audience Groups.
• Support for Mailchimp SIGNUP merge field.

[matticbot]

Caution: This PR has changes that must be merged to WordPress.com
Hello jeffersonrabb! These changes need to be synced to WordPress.com - If you 're an a11n, please commandeer, review, and approve D35555-code before merging this PR. Thank you!

[jetpackbot]

Thank you for the great PR description!

When this PR is ready for review, please apply the [Status] Needs Review label. If you are an a11n, please have someone from your team review the code if possible. The Jetpack team will also review this PR and merge it to be included in the next Jetpack release.

Scheduled Jetpack release: December 3, 2019.
Scheduled code freeze: November 26, 2019

Generated by 🚫 dangerJS against 48f2038

[matticbot]

jeffersonrabb, Your synced wpcom patch D35555-code has been updated.

[jeherve]

I gave it a quick test, and I have some questions. It seems to work well for me overall, and it doesn't bring existing forms either.

In "Mailchimp Groups" select one or more groups.

Should I be able to do that when I set it as "Dropdown / can only select one at a time" when I created the groups?

Verify the email appears on the list in the Mailchimp dashboard and that it is in the correct groups and has the correct SIGNUP value.

I could find the group info, but not the SIGNUP value. I am not sure where to check that when looking at my subscriber list.

[jeffersonrabb]

It seems to work well for me overall, and it doesn't bring existing forms either.

@jeherve quick confirmation - in the above, "bring" === "break"?

[jeffersonrabb]

I could find the group info, but not the SIGNUP value. I am not sure where to check that when looking at my subscriber list.

I believe I missed a step here. The field has to be defined in Mailchimp following these instructions: https://mailchimp.com/help/determine-webpage-signup-location/

When set up successfully you should see the values in the subscriber list as in this screenshot:

This makes me wonder if the block should also allow defining the field name, so we don't lock in to the name SIGNUP, but I'm reticent to add more complexity.

[jeherve]

quick confirmation - in the above, "bring" === "break"?

Oh yes, sorry!

[jeherve]

Thanks for the extra details.

This makes me wonder if the block should also allow defining the field name, so we don't lock in to the name SIGNUP, but I'm reticent to add more complexity.

Since this has to be set properly by the site owner first, it may indeed be nice to have matching fields in the block properties. On the plus side, this would also make it easier for non-english folks who may not understand nor want to have a "Signup" field.

[matticbot]

jeffersonrabb, Your synced wpcom patch D35555-code has been updated.

[jeherve]

This works well. I think the links to Mailchimp are nice to give a bit more info. Since their docs are focussed on creating whole forms from their interface, I wonder if we should link to our own support docs to explain how to do this from the audience settings instead; I struggled a bit to get the fields to work in the first place, so I think some more detailed docs could help there.

Maybe we can ask for help from JPOP Quill and update the existing links once we have docs? What's your take on this?

I also have another comment, but I don't think that's blocking, that can be addressed in a future PR. Approving for now.

[matticbot]

jeffersonrabb, Your synced wpcom patch D35555-code has been updated.

[matticbot]

jeffersonrabb, Your synced wpcom patch D35555-code has been updated.

[jeffersonrabb]

Maybe we can ask for help from JPOP Quill and update the existing links once we have docs? What's your take on this?

That's a good idea. I'll follow up on this after this lands and we can roll this improvement into future work on the block.

[jeherve]

This should be good to merge now. 👍