For example, if we have a list of to-dos and want to add to it, perhaps through a form submission, we use POST HTTP requests to send a request with a payload for processing and potential persistence. All we have to do is call our hook at the top of our component.When working with APIs we oftentimes want to send data to the server for processing. That means it works with SSR (server side rendering).Ī custom hook that makes our HTTP request allows us to make our components much more concise. To cut down on our reused code, we can use a custom hook as a special abstraction, which we can write ourselves from a third party library (like we are here, using the library react-fetch-hook). Over time, you may realize that it gets a bit tedious and time-consuming to keep writing the useEffect hook with all of its boilerplate within every component in which you want to fetch data.
#React fetch how to#
How to Fetch Data in React Using a Custom React Hook (useFetch) Things to keep in mind while using async/await:Īwait can only be used inside an async block.Īwait waits until the function(“promise”) resolves or rejects. It enhances readability and flow of your code. In summary, async/await is a cleaner syntax to write asynchronous Javascript code. To create an async function all we need to do is add the async keyword before the function definition, we would be converting our previous example to an async/await syntax: We have to be aware of the fact that when we use useEffect the effect function (the first argument) cannot be made an async function. The one thing you need to know about async functions is that they always returns a promise.
#React fetch code#
Why async/await ? Well, simply put, async/await allows us to write asynchronous code in a synchronous manner. finally() callbacks, promises andsimply get back our asynchronously resolved data as if we were writing synchronous code without promises altogether. The benefit of this is that it enables us to remove our. Async/await is a relatively new way to write asynchronous code in Javascript. In ES7, it became possible to resolve promises using the async / await syntax. What Axios enables us to do is to use the exact same promise syntax as fetch - but instead of using our first then callback to manually determine whether the response is okay and throw an error, Axios takes care of that for us.įetch Data in React Using async / await syntax
#React fetch install#
With Axios, we get the ability to intercept and cancel request, it also has a built-in feature that provides client-side protection against cross-site request forgery.Īxios is a React/Javascript library, so for us to use it in our app we would need to install it first. Axios is an easy to use promise-based HTTP client for the browser and node.js. The second pattern is by making use of Axios. Instead we see either our data on the page if the request was made successfully, or that there was an error in making the request if not. In it, we set loading to false, so that we no longer see our loading text.
finally() callback is a function that is called when our promise has resolved successfully or not. If there's an error we return the text "Error!". Here in our example, we are putting our error data in state with setError. Using fetch, for us to handle the errors, we throw response as an error for it to handled by our catch callback.
If it’s not an okay response, we assume there was an error making the request.
We call back a response as JSON data if the response is ok. then() callback, was used to see if the response was okay ( response.ok). Within the useEffect we declare the API endpoint inside of our fetch function, the. In the code above, we have created a very simple functional component that makes a fetch request once the component gets mounted and sends back the response to us in the data state. Enter fullscreen mode Exit fullscreen mode
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