Introduction
Have you encountered the frustrating “Expecting a parsed GraphQL document” error while working with React Apollo GraphQL? Don’t worry, you’re not alone! In this article, we will explore the cause of this error and provide you with a step-by-step guide to resolve it. So, let’s dive into the world of React Apollo GraphQL and conquer this error together!
Understanding the Error
The error message “Expecting a parsed GraphQL document. Perhaps you need to wrap the query string in a ‘gql’ tag?” can be quite perplexing. This error usually occurs when you try to update the cache after a mutation and encounter issues with the GraphQL document. The error message suggests wrapping the query string in a ‘gql’ tag, but what does that mean?
Investigating the Code
To better understand the issue, let’s examine the code snippet that triggers the error. In your code, you have a mutation that succeeds, and afterward, you attempt to update the cache using the readQuery and writeQuery methods provided by Apollo Client. However, something seems to be amiss.
The Role of gql Tag In GraphQL, the gql tag is used to parse and define GraphQL queries or mutations. It ensures that the query or mutation is a properly structured GraphQL document. The error message suggests that you might have forgotten to wrap your query string in the gql tag.
Fixing the Issue To resolve the “Expecting a parsed GraphQL document” error, follow these steps:
Import the Required Dependencies
Make sure you have imported the necessary dependencies correctly. Import gql along with ApolloClient and InMemoryCache from the @apollo/client package.
Wrap the Query String
Ensure that you wrap your query string, in this case FETCH_CARDS, with the gql tag. This step is crucial for the proper parsing of the GraphQL document.
Update the Code
In your code snippet, replace the FETCH_CARDS query import with the wrapped version using the gql tag. Verify that you have made the change correctly and that the query is now wrapped.
Conclusion
By following these steps, you should be able to fix the “Expecting a parsed GraphQL document” error in your React Apollo GraphQL code. Remember to import gql correctly, wrap your query strings, and ensure proper dependency management. Now you can confidently update the cache after a mutation without encountering this error.
We hope this guide has helped you unravel the mystery behind the error and provided you with a clear solution. Happy coding with React Apollo GraphQL!
