What triggers a Shopify Function?

Extensions
1

Hi all,

I’m building a checkout-ui-extension app that creates an extra field in the checkout. The selected value is placed in a metafield. But when i look at the function input the content of this metafield is null. Which is expected because there no selection made. But after updating the metafield from the checkout-ui-extension the function is not triggered again.

Question: How can I trigger the function when there is a new selection made?

Update metafield inside checkout-ui-extension

applyMetafieldsChange(
    {
        type: 'updateMetafield',
        namespace: '$app:ils',
        key: 'selected_delivery',
        value: <selectedValue>,
        valueType: 'string',
    }
);

Input GraphQL query

query RunInput {
    deliveryCustomization {
        metafield(namespace: "$app:ils", key: "selected_delivery") {
            value
        }
    }

    cart {
        deliveryGroups {
            deliveryOptions {
                description
                    handle
                    title
                    code
            }
        }
    }
}

Input JSON

{
  "deliveryCustomization": {
    "metafield": null
  },
  "cart": {
    "deliveryGroups": [
      {
        "deliveryOptions": [
          {
            "description": "",
            "handle": "61a65f33b3598880127e654812d5b554-01ca9f1dd9a59fa4e1c6c4a7081d88ef",
            "title": "Standaard",
            "code": "Standaard"
          }
        ]
      }
    ]
  }
}

checkout-ui-extension TOML

[[extensions.metafields]]
namespace = "$app:ils"
key = "selected_delivery"

function TOML

  [extensions.input.variables]
  namespace = "$app:ils"
  key = "selected_delivery"
2

Did you define metafields in extension configuration file?

3

@remy727 I did in the checkout-ui-extension do i need to do the same in the function-extension as well?

I included it in the post.

4

Yes. You need to include [extensions.input.variables] in Shopify functions configuration file.

5

@remy727 Thank you for the direction I need to go. So I changed the checkout-ui-extension metafield to JSON. But I have a problem with “using” it in my function GraphQL. In de GraphQL I don’t need the variable. I only need it in my function logic.

I updated the function to the values below. But now $selected is not used and that is not permitted. I’m I missing something from the docs?

Metafield value

JSON.stringify({selected: "dhl"})

Function TOML

  [extensions.input.variables]
  namespace = "$app:ils"
  key = "selected_delivery"

Function input GraphQL

query RunInput($selected: String) {
    cart {
        deliveryGroups {
            deliveryOptions {
                description
                    handle
                    title
                    code
            }
        }
    }
}
6

Does this work?

query RunInput {
    deliveryCustomization {
      metafield(
       namespace: "$app:ils",
       key: "selected_delivery"
      ) {
        value
      }
    }
    cart {
      deliveryGroups {
        deliveryOptions {
          description
          handle
          title
          code
        }
      }
  }
}
7

@remy727 when I remove the extensions.input.variables from the TOML file (because I don’t use the input) I do get the standard data back that is in the metafield. But I think i’m making a scoping error. Because this is not tight to the current cart right. So I think I need to update the Cart Attributes instead?

mutation {
  deliveryCustomizationCreate(deliveryCustomization: {
    functionId: "0e07aaa2-xxxxxxx"
    title: "Filter delivery methods based on selected carrier"
    enabled: true
    metafields: [
      {
        namespace: "ils",
        type: "json",
        key: "selected_delivery",
        value: "{\"selected\":\"\"}"
      }
    ]
  }) {
    deliveryCustomization {
      id
    }
    userErrors {
      message
    }
  }
}
8

Sorry, I revisited your question again and I understood what you want :smile:

Question: How can I trigger the function when there is a new selection made?

You need to update cart(maybe line attributes) via checkout UI extension to trigger Shopify function.

So I think I need to update the Cart Attributes instead?

Yes. You can check Adjust Prices via Checkout UI Extension to see how to update cart line attributes via checkout UI extension.

1 Like
9

@remy727 yes, this worked! Thanks for all the assist.