Context and Hooks

In this advanced guide, we will explore how to work with Event Context and create your own hooks in Wooks HTTP.

Create useUserProfile composable

As an example, let's create a composable that resolves the user profile.

import { useAuthorization, useHttpContext } from '@wooksjs/event-http';

interface TUser {
    username: string;
    age: number;
    // ...
}

export function useUserProfile() {
    // 1. Get custom-typed context
    const { store } = useHttpContext<{ user: TUser }>();
    const user = store('user');

    // 2. Use basic credentials approach to get the user name in this example
    const { basicCredentials } = useAuthorization();
    const username = basicCredentials()?.username;

    // 3. User profile initializer
    const userProfile = () => user.init('data', () => readUser(username))

    // Abstract readUser function
    function readUser(username: string): Promise<TUser> {
        // Return the user profile from the database
    }

    return {
        username,
        userProfile,
    };
}

// Example of usage of our useUserProfile composable
app.get('/user', async () => {
    const { username, userProfile } = useUserProfile();
    console.log('username =', username);
    const data = await userProfile();
    return { user: data };
});

In the above example, we define the useUserProfile composable that makes use of the useHttpContext and useAuthorization hooks provided by Wooks HTTP. The composable resolves the user profile by retrieving the user data from the event context store or fetching the data from the database.

Create useHeaderHook

Here's an example of a custom hook for setting headers.

import { useSetHeaders } from '@wooksjs/event-http';
import { attachHook } from '@wooksjs/event-core';

function useHeaderHook(name: string) {
    const { setHeader, headers } = useSetHeaders();

    return attachHook(
        {
            name,
            type: 'header',
        },
        {
            get: () => headers()[name] as string,
            set: (value: string | number) => setHeader(name, value),
        }
    );
}

// Usage
app.get('/test', () => {
    const myHeader = useHeaderHook('x-my-header');
    myHeader.value = 'header value';
    // *Please note that useSetHeader('x-my-header') will work similarly*
    return 'ok';
});

// Result:
// 200
// Headers:
// x-my-header: header value

In the above example, we define the useHeaderHook function that creates a custom hook for setting headers. The hook utilizes the useSetHeaders composable provided by Wooks HTTP to access the setHeader and headers functions. It returns an ref-object that allows you to get and set the value of the specified header.

How to Restore the Event Context

To restore the Event Context within a handler, you can use the restoreCtx and functions provided by the useHttpContext hook.

import { useHttpContext } from '@wooksjs/event-http';

async function someHandler() {
    const { restoreCtx, clearCtx } = useHttpContext();
    await ... // Some async operations
    restoreCtx();
    // Here the Wooks Context is restored
}

In the example above, within the someHandler function, we use the useHttpContext hook to retrieve the restoreCtx and clearCtx functions. After performing some async operations, we can call restoreCtx() to restore the Event Context. This allows subsequent operations within the handler to have access to the restored context.

By using the restoreCtx function, you can ensure that the Event Context is maintained and accessible throughout the execution of your handler.

That's how you can work with Event Context and create your own hooks in Wooks HTTP. Refer to the Event Context for more details.

Context and Hooks ​

Create useUserProfile composable ​

Create useHeaderHook ​

How to Restore the Event Context ​

Context and Hooks

Create useUserProfile composable

Create useHeaderHook

How to Restore the Event Context