Graphql checkout tutorial

[atwixfirster]

Purpose of this PR

This PR adds a tutorial for the checkout workflow regarding issue #589.

PR contains a pack of GraphQl API functions which is currently under develop:

• setShippingAddressesOnCart
• setBillingAddressOnCart
• setShippingMethodsOnCart
• setPaymentMethodOnCart
• applyCouponToCart
• removeCouponFromCart
• setGuestEmailOnCart
• placeOrder

Affected URLs

New URLs:

• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-customer.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-shopping-cart.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-add-product-to-cart.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-shipping-address.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-billing-address.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-shipping-method.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-payment-method.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-coupon.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-quote-email.html
• https://devdocs.magento.com/guides/v2.3/graphql/tutorials/checkout/checkout-place-order.html

Links to source code

• https://github.com/magento/graphql-ce/blob/2.3-develop/app/code/Magento/QuoteGraphQl/etc/schema.graphqls

Thank you!

whatsnew
Added the GraphQL checkout tutorial, which provides an overview of the steps you need place an order on behalf of a guest or logged-in user.

[devops-devdocs]

An admin must run tests on this PR before it can be merged.

[rogyar]

Hi @keharper. Could you check please if you already have this information prepared?
If not, I would suggest splitting this PR into smaller chunks.

Thank you

[keharper]

Wow. Just wow.

This is massive, and I'm absolutely stunned. It'll take a while to fully process this and figure out everything. Give me a week to figure this out.

[keharper]

Thanks for this fantastic tutorial. I've added a lot of quote reference material in the develop branch since you submitted the tutorial. You might want to add more links to those topics.

[atwixfirster]

@keharper , moving PR to your plate again :)

All suggestions have been implemented.

Please verify. Thank you!

[keharper]

Global: Change all instances of {{ SOMETHING }} to { SOMETHING } or create a different way to represent tutorial variables. Don't change our system variables like {{ page.baseurl }}

The system attempts to process strings like {{ CART_ID }} in the same way as {{ page.baseurl }}, and so they display as null.

[atwixfirster]

Global: Change all instances of {{ SOMETHING }} to { SOMETHING } or create a different way to represent tutorial variables. Don't change our system variables like {{ page.baseurl }}

The system attempts to process strings like {{ CART_ID }} in the same way as {{ page.baseurl }}, and so they display as null.

done

[keharper]

Last round, I think. Don't forget to update the samples for adding products to the cart.

[atwixfirster]

@keharper

Don't forget to update the samples for adding products to the cart.

This point already done in the guides/v2.3/graphql/tutorials/checkout/checkout-add-product-to-cart.md

[keharper]

running tests

[keharper]

running tests

[ghost]

Hi @atwixfirster, thank you for your contribution!
Please, complete Contribution Survey, it will take less than a minute.
Your feedback will help us to improve contribution process.

[keharper]

Yippee-ki-yay. Thank you @atwixfirster for this massive contribution. You're a star.

[atwixfirster]

Yippee-ki-yay. Thank you @atwixfirster for this massive contribution. You're a star.

Thank you, @keharper 😊

Thank you for all your hard work on this one 👍