The world of programming is always changing, evolving, integrating new concepts, techniques and methodologies to make the overall process more efficient, more dynamic and more functional for both the programmers and the end-users. One such concept is the Apollo FetchPolicy in the world of GraphQL and Typescript which is making persistent waves. Apollo Client’s fetch policies determine how it interacts with your GraphQL server and your Apollo cache. This becomes an effective tool when you want to achieve a caching mechanism to prevent unnecessary requests to a server.
Apollo’s `fetchPolicy` option plays a key role in specifying how Apollo Client uses the cache for reading and writing data. Let’s consider a problem we aim to solve: reducing the load on our GraphQL server by minimizing the calls to it and simultaneously ensuring that data shown to users is up to date. Apollo’s `fetchPolicy` offers some valuable ways to solve this problem.
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Apollo fetchPolicy
Apollo fetchPolicy is a set of directives that specify how Apollo Client uses the result of a query – it could use cached data, make a network request, or a combination of both. To understand this in a practical way, let’s take an example.
const { loading, error, data } = useQuery(GET_DOGS, {
fetchPolicy: 'cache-and-network'
});
In the above Typescript code, the `fetchPolicy` is set to ‘cache-and-network’ for GET_DOGS query. The ‘cache-and-network’ policy returns the initial data from cache (if available) and then sends a network request to the server to ensure its up-to-date.
Understanding Different Types of FetchPolicy
Apollo offers multiple fetchPolicy options each designed to cater to different use-cases.
The key policies include:
- ‘cache-first’: This is the default policy. Apollo Client searches for result in cache first. If found, it serves from cache otherwise it sends a request to the server.
- ‘network-only’: This fetchPolicy does not cache any data and always sends a request to the server.
- ‘cache-and-network’: Sends a request to server and also reads from cache. It first serves result from cache, then sends a request to server to verify and update any potentially changed data.
- ‘no-cache’: Similar to ‘network-only’ but Apollo Client won’t do any caching for future queries.
- ‘standby’: Only used for queries watched by other queries. Does not deliver any network interface results.
Each `fetchPolicy` provides a suitable solution depending on the situation and requirement.
And, that is a brief look into Apollo `fetchPolicy` in Typescript. It is indeed a game-changer when it comes to managing server load and providing efficient data access!
Takeaways and Interesting Facts
By understanding and wisely using Apollo `fetchPolicy`, we can streamline the flow of data in our applications. Not only does this option optimize the use of network resources, but it also offers a seamless end-user experience. Furthermore, working with Apollo Client in a Typescript environment allows us to take full advantage of strong typing and autocompletion with IDE support, making bug detection and debugging process easier.
Remember, in the world of GraphQL and Typescript, Apollo `fetchPolicy` is your golden ticket to efficient data access that’s both cache- and network-optimized.
