react-use-async-hook/README.md

Managed state for async tasks

⚠️ No new features! This repository is here for legacy purposes.
Use [react-use-async-fn](https://www.npmjs.com/package/react-use-async-fn) instead
for a better experience.

## React Hook for async tasks

Perform async tasks like calling your API and manage them through react hooks


### Installing

Using NPM:

```bash
npm i react-use-async-hook
```

Using yarn:

```bash
yarn add react-use-async-hook
```

### Usage

This hooks takes the following options:

- `task`: (required) A function which gets performs the async task.
- `dataLoader`: (optional) A function which extracts the required data from the async task.
For example, we may not need the whole response object from the API response,
but just the data that is returned by the API.
- `initialData`: (optional, defaults to null) The place holder data to be used in place of the original data
until the data is fetched from the async task.
- `executeOnLoad`: (optional, defaults to true) Should the task execute every time with the useEffect hook is executed. 
- `autoExecute`: Alias for `executeOnLoad`. If both are given, this is ignored.
- `onError`: (optional) This function is called when an error occurs. The default behavior just logs to the console.
- `executeOnChange`: (optional, defaults to true) If true, Execute the task if either of `dataLoader`, `onError`, `task` change. The execution behavior for various combinations are described below.

| executeOnLoad  | executeOnChange   | Behavior 
| --- | --- | ----------- |
  | true           | true              | executes on load and executes on task change |
  | true           | false             | executes on load and doesn't execute on task change |
  | false          | true              | doesn't executes on load, executes on task change |
  | false          | false             | doesn't executes on load, doesn't execute on task change |

This hook return an object containing:

- `data`: The data that is returned by the async task. This is obtained by passing this
value to the `dataLoader`.
- `loading`: Boolean indicating if the async task is still in progress.
- `error`: The error that occurred during the async task.
- `taskResult`: The whole returned value from the async task.  
- `execute`: A function that can be called to execute the task when ever needed.

### Example
```js
import useAsync from 'react-use-async'

function List (props){
  const makeAPICall = useCallback((page)=>{
      // Simulated API call
      return new Promise((resolve) => {
          setTimeout(() => {
              resolve({
                  data: [1,2,3],
                  page,
              })
          }, 3000);
      })
  }, []);

  let {
      data, loading, error, execute: refresh
  } = useAsync({
      task: makeAPICall,
      dataLoader: useCallback((response) => {
          return response.data;
      }, []),
      initialData: useMemo(()=>([]), []),
  });

  return (
      <>
        {
          loading ? (
            <>
              <div>Loading...</div>
            </>
          ) : (
            <div>
              <button type="button" onClick={() => refresh(1)}>Refresh</button>
              {data.map(x => <div key={x}>{x}</div>)}
            </div>
          )
        }
      </>
  )
}
```