Refine•2y ago

How to define GraphQL Schema?

Hey I am running a backend django + strawberry and refine with graphql to make some calls and read data.
I keep getting
TypeError: Cannot read properties of undefined (reading 'count')

When trying to run a simple:
const { data, isLoading, error } = useList({
resource: "vehicle_list",
meta: { gqlQuery: VEHICLES_LIST_QUERY },
});

with this query:
export const VEHICLES_LIST_QUERY = gql


query VehiclesList {
    vehicles {
      id
      vin
      make
      model
      year
      driver {
        id
        name
        email
        licenseNumber
      }
      gateway {
        id
        serialNumber
        firmwareVersion
      }
    }
  }


query VehiclesList {
    vehicles {
      id
      vin
      make
      model
      year
      driver {
        id
        name
        email
        licenseNumber
      }
      gateway {
        id
        serialNumber
        firmwareVersion
      }
    }
  }

;

Is there a specific Graphql query response format that suppose to work?
Seems like it is expecting data in a certain format.

kapa.ai•4/22/24, 12:10 AM

Hi @Valugar. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base.

kapa.ai•4/22/24, 12:10 AM

----------------------
Yes, Refine expects the GraphQL response in a certain format. For the hook, the response should include a field that indicates the total number of records. This is used for pagination purposes.

Here is an example of how the response should look like:

In this example, should be replaced with the name of your resource, which is in your case. The field should contain an array of your resource items. Each item should at least contain an field.

If your GraphQL server does not return the data in this format, you might need to create a custom data provider to adapt the server response to the format that Refine expects. You can refer to the Refine's GraphQL documentation (https://refine.dev/docs/packages/documentation/data-providers/graphql/) for more information about its GraphQL implementation.

Also, please note that the error message indicates that the hook is trying to read the property of an undefined object. This might be caused by the server returning or for the field or the entire resource. Please make sure that your server returns a valid object for the resource and a valid number for the field.
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kapa.ai•4/22/24, 12:10 AM

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constitutional-coralOP•4/22/24, 12:15 AM

@kapa.ai
so given my schema, how should I change it to fit the expected schema?

@strawberry.type
class VehicleConnection:
nodes: List[VehicleType]
totalCount: int

@strawberry.type
class Query:
@strawberry.field
async def vehicles(self, info: strawberry.Info, where: Optional[JSON] = None, sort: Optional[str] = None, start: Optional[int] = None, limit: Optional[int] = None) -> VehicleConnection:
query = Vehicle.objects.all()

Apply filtering
if where:
query = query.filter(**where)

Apply sorting
if sort:
query = query.order_by(sort)

# Apply pagination
if start is not None and limit is not None:
query = query[start:start + limit]

totalCount = await sync_to_async(query.count)()
vehicle_list = await sync_to_async(list)(query)
return VehicleConnection(nodes=vehicle_list, totalCount=totalCount)

kapa.ai•4/22/24, 12:15 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:16 AM

----------------------
Your schema seems to be correctly defined for use with Refine. The class has the and fields, which are required by Refine. The field in the class returns a , which is also correct.

The field should contain an array of objects, and each object should at least contain an field. The field should contain the total number of objects.

Here is an example of how the response should look like:

kapa.ai•4/22/24, 12:16 AM

If you are still encountering the error, it might be due to the server returning or for the field or the entire object. Please make sure that your server returns a valid object for and a valid number for .
----------------------
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kapa.ai•4/22/24, 12:16 AM

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constitutional-coralOP•4/22/24, 12:20 AM

@kapa.ai But this is exactly the query response I get from my schema.
So it is proper.
Is there something maybe that is badly configured with the data provider?

const { data, isLoading, isError } = useList({
resource: "vehicles_list",
meta: { gqlQuery: VEHICLES_LIST_QUERY },
});

const client = new GraphQLClient(API_URL, {
fetch: (url: string, options: RequestInit) => {
const token = localStorage.getItem("token"); // Ensure you get the token from a secure place
return fetch(url, {
...options,
headers: {
...options.headers,
Authorization: ,
},
});
},
});

const gqlDataProvider = dataProvider(client);

kapa.ai•4/22/24, 12:20 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:20 AM

----------------------
Your GraphQL data provider setup seems correct. You're creating a new with your API URL and a fetch function that includes the authorization token in the headers. Then, you're passing this client to the function from Refine to create the data provider.

However, the issue might be related to the resource name you're using in the hook. In your hook, you're using as the resource name:

But in your GraphQL query, the resource name is :

The resource name in the hook should match the resource name in your GraphQL query. Try changing the resource name in the hook to :

If you're still encountering the error, it might be helpful to log the

data

data

and variables to see what data you're receiving and whether there are any errors:

This might give you more information about what's going wrong.
----------------------
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----------------------

kapa.ai•4/22/24, 12:20 AM

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constitutional-coralOP•4/22/24, 12:24 AM

@kapa.ai Ok you are right. Now I have this:
export const VehicleListPage = () => {
const { data, isLoading, isError } = useList({
resource: "vehicles",
meta: { gqlQuery: VEHICLES_LIST_QUERY },
});

if (isLoading) {
return <div>Loading...</div>;
}
if (isError) {
return <div>Something went wrong!</div>;
}
console.log(data.data.nodes)

But the data.data.nodes seems to give a warning
Property 'nodes' does not exist on type 'BaseRecord[]'.ts(2339)

Even though it is working

kapa.ai•4/22/24, 12:24 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:24 AM

----------------------
The warning you're seeing is a TypeScript type checking warning. It's saying that the property does not exist on the type . This is because the

data

data

returned by is typed as , which does not have a property.

To fix this, you can define a type for your vehicle data and use it in the hook. Here's an example:

In this example, is the type for a vehicle, and is the type for the data returned by the hook. The hook is parameterized with , which tells TypeScript that

data

data

is of type . This way, TypeScript knows that

data

data

has a property.
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----------------------

kapa.ai•4/22/24, 12:24 AM

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constitutional-coralOP•4/22/24, 12:26 AM

@kapa.ai but the returned data structure is the same - console.log(data) returns:
data
:
nodes
:
(2) [{…}, {…}]
totalCount
:
2
[[Prototype]]
:
Object
total
:
undefined

kapa.ai•4/22/24, 12:26 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:27 AM

----------------------
The returned data structure is indeed the same, but TypeScript is a statically typed language, which means it checks the types of variables at compile time. Even though the actual data returned at runtime has a property, TypeScript doesn't know this at compile time because the type doesn't have a property.

To fix the TypeScript warning, you can define a type for the returned data and use it in the hook. Here's an example:

In this example, is the type for a vehicle, and is the type for the data returned by the hook. The hook is parameterized with , which tells TypeScript that

data

data

is of type . This way, TypeScript knows that

data

data

has a property and a property.
----------------------
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----------------------

kapa.ai•4/22/24, 12:27 AM

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constitutional-coralOP•4/22/24, 12:29 AM

@kapa.ai why is this keep returning the data as data
:
{totalCount: 2, nodes: Array(2)}
total
:
undefined

instead of IVehicleData?

I changed it to fit what you did.
Could it be the resource issue?

kapa.ai•4/22/24, 12:29 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:29 AM

----------------------
The

data

data

object returned by the hook is of type as you've defined it. However, when you log it to the console with , it's displayed as a plain JavaScript object. This is because prints the runtime value of the object, not its TypeScript type.

The field is because it's not included in the GraphQL response. The hook expects the total number of records to be in the field, not the field. If you want to access the total number of records, you should use , not .

The argument in the hook should match the name of the resource in your GraphQL query. If the resource name in the hook doesn't match the resource name in the GraphQL query, the hook might not be able to correctly fetch and process the data.

If you're still encountering issues, it might be helpful to check the network tab in your browser's developer tools to see the exact request that's being sent and the response that's being received. This might give you more information about what's going wrong.
----------------------
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----------------------

kapa.ai•4/22/24, 12:29 AM

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constitutional-coralOP•4/22/24, 12:33 AM

@kapa.ai But if you see inside the useList, it has this part:

if (mode === "client") {
data = {
...data,
data: data.data.slice((current - 1) * pageSize, current * pageSize),
total: data.total,
};
}

so it breaks the data differently.
It puts it in the data/total structure.

kapa.ai•4/22/24, 12:33 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:34 AM

----------------------
The code snippet you provided is part of Refine's internal implementation of the hook. It's handling the case where pagination is done on the client side (). In this case, it slices the data array to get the current page of data and assigns it to , and it assigns the total number of records to .

However, this doesn't affect the structure of the data returned by the hook. The hook still returns an object with a

data

data

property, which is the data fetched from the server. The structure of this

data

data

object depends on the server response and the type parameter you pass to .

In your case, you're passing as the type parameter to , so TypeScript expects

data

data

to be of type . This means

data

data

should have a property, which is an array of objects, and a property, which is a number.

If you want to access the total number of records, you should use , not . The field is not included in the GraphQL response, so it's . The total number of records is in the field.

Here's how you can access the data and the total count:

If you're still encountering issues, it might be helpful to check the network tab in your browser's developer tools to see the exact request that's being sent and the response that's being received. This might give you more information about what's going wrong.
----------------------
Note: you can ask me a follow up question by @ mentioning me again

----------------------

kapa.ai•4/22/24, 12:34 AM

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constitutional-coralOP•4/22/24, 12:34 AM

@kapa.ai So I need to do something like data = data.data
to then be able to use data.nodes

kapa.ai•4/22/24, 12:34 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:35 AM

----------------------
Yes, if the data returned by the hook is structured in a way that the actual data is under , you would need to reassign

data

data

to to access directly from

data

data

. Here's how you can do it:

However, please note that this is not the typical usage of the hook. Normally, you should be able to access and directly from

data

data

without having to reassign

data

data

to . If you need to do this, it might indicate that there's something unusual about the way your GraphQL server is returning data or the way your data provider is processing it.
----------------------
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----------------------

kapa.ai•4/22/24, 12:35 AM

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constitutional-coralOP•4/22/24, 12:39 AM

@kapa.ai Still something doesn't make sense.
The data returned from the useList is:

data
:
{totalCount: 2, nodes: Array(2)}
total
:
undefined

This is the console log. You can't argure with this.
And it is different than the graphql response.
So useList is modifying the data and parsing it differently.
Why is this?
How can I change this?

kapa.ai•4/22/24, 12:39 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:39 AM

----------------------
The hook in Refine does indeed modify the data returned from the server. It wraps the server response in an object with

data

data

and properties. The

data

data

property contains the actual data returned from the server, and the property contains the total number of records.

In your case, the server response is , so the hook wraps this in an object like this: .

The property is because the server response does not include a field. The hook expects the total number of records to be in the field, not the field.

If you want to access the total number of records, you should use , not . Here's how you can do it:

If you want to change how the hook processes the server response, you would need to create a custom data provider. The data provider is responsible for making requests to the server and processing the server responses. You can create a custom data provider that processes the server responses in a way that fits your needs. You can refer to the Refine's documentation on data providers (https://refine.dev/docs/data/data-provider/) for more information on how to create a custom data provider.
----------------------
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----------------------

kapa.ai•4/22/24, 12:39 AM

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constitutional-coralOP•4/22/24, 12:42 AM

@kapa.ai Ok so how can I change the schema to have the 'total' populate data and not be undefined?
the TotalCount is my addition I added to the schema but I can change it.

kapa.ai•4/22/24, 12:42 AM

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kapa.ai•4/22/24, 12:42 AM

----------------------
To have the field populated in the data returned by the hook, you would need to include a field in the server response. This means you would need to change your GraphQL schema and resolver to include a field.

Here's how you can do it:

In this example, I've changed to in the class, the resolver, and the return statement of the resolver.

After making these changes, the field should be populated in the data returned by the hook:

kapa.ai•4/22/24, 12:42 AM

Please note that this will change the structure of the server response, so you might need to update other parts of your code that depend on the server response.
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kapa.ai•4/22/24, 12:42 AM

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constitutional-coralOP•4/22/24, 12:44 AM

@kapa.ai Not working. The total is nested inside data.data.total, where the useList creates the total at the data.total.

kapa.ai•4/22/24, 12:44 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/22/24, 12:44 AM

----------------------
The hook from Refine expects the total number of records to be in the field of the response. If you want to use instead of , you would need to create a custom data provider to adapt the server response to the format that Refine expects.

Here's an example of how you can create a custom data provider:

In this example, I'm creating a custom data provider that wraps the base GraphQL data provider from Refine. I'm overriding the method to adapt the server response to the format that Refine expects. The method fetches the data using the base data provider, then it returns an object with

data

data

and properties. The

data

data

property contains the field from the server response, and the property contains the field from the server response.

After creating this custom data provider, you can use it in your app like this:

```jsx
import dataProvider from "./dataProvider";

kapa.ai•4/22/24, 12:45 AM

const App = () => (
<Admin dataProvider={dataProvider}>
{/* Your resources and routes */}
</Admin>
);
```

Please note that this is a simplified example. Depending on your needs, you might need to customize the data provider further. You can refer to the Refine's documentation on data providers (https://refine.dev/docs/data/data-provider/) for more information on how to create a custom data provider.
----------------------
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----------------------

kapa.ai•4/22/24, 12:45 AM

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constitutional-coralOP•4/22/24, 4:50 AM

@kapa.ai Ok thank you.
Now for another question I have about the schema for the graphql.
I am using Django to create the backend server with strawberry.
Are there tools I can use to create schemas that will work with refine graphql?
I am currently creating the schema as I see fit, but I don't know if the query response works with refine graphql.

kapa.ai•4/22/24, 4:50 AM

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kapa.ai•4/22/24, 4:50 AM

----------------------
Refine's GraphQL data provider is built to work with any GraphQL API, so you can use any tool to create your GraphQL schema as long as it follows the GraphQL specification. Strawberry is a good choice for creating GraphQL APIs in Django.

However, there are a few things to keep in mind to ensure that your GraphQL API works well with Refine:

Resource Names: The resource names in your GraphQL schema should match the resource names you use in Refine. For example, if you have a resource in Refine, you should have a query in your GraphQL schema.
Pagination: Refine expects the server to handle pagination. This means your GraphQL queries should accept arguments for pagination (such as and ), and your server should return the correct page of data based on these arguments.
Sorting and Filtering: Refine also expects the server to handle sorting and filtering. Your GraphQL queries should accept arguments for sorting and filtering, and your server should return the data sorted and filtered based on these arguments.
Total Count: Refine expects the total number of records to be in the field of the response. If you want to use a different field for the total count, you would need to create a custom data provider to adapt the server response to the format that Refine expects.

Here's an example of how you can define a GraphQL schema in Strawberry that works with Refine:

```python
import strawberry
from strawberry.django import auto

@strawberry.type
class Vehicle:
id: auto
vin: auto
make: auto
model: auto
year: auto

@strawberry.type
class VehicleConnection:
nodes: List[Vehicle]
totalCount: int

kapa.ai•4/22/24, 4:50 AM

@strawberry.type
class Query:
@strawberry.field
def vehicles(self, info, start: int = 0, limit: int = 10, sort: Optional[str] = None, where: Optional[JSON] = None) -> VehicleConnection:
# Fetch, sort, filter, and paginate vehicles based on the arguments
# ...
return VehicleConnection(nodes=vehicles, totalCount=total_count)
VehicleVehicleConnectionvehiclesQuerystartlimitsortwhere` arguments.

You can refer to the Strawberry documentation (https://strawberry.rocks/docs) for more information on how to create GraphQL schemas in Strawberry.
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