I have a middleware to verify if certain paths are public or not, but I want to use sequence with typescript type safety, how can I do that?
#sequence middleware with typescript
meager folio
sly epochBOT
Hi @meager folio. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:
You can use the defineMiddleware() utility function provided by Astro to create middleware with TypeScript type safety. Here's an example of how you can do this:
import { defineMiddleware } from "astro:middleware";
export const onRequest = defineMiddleware((context, next) => {
// Your middleware logic here
});
In this example, context and next are automatically typed, providing you with type safety.
If you're using JsDoc for type safety, you can use MiddlewareRequestHandler:
/**
* @type {import("astro").MiddlewareResponseHandler}
*/
export const onRequest = (context, next) => {
// Your middleware logic here
};
To chain multiple middleware functions in a specified order, you can use the sequence() function:
import { sequence } from "astro:middleware";
async function middleware1(_, next) {
// Your middleware logic here
const response = await next();
return response;
}
async function middleware2(_, next) {
// Your middleware logic here
const response = await next();
return response;
}
export const onRequest = sequence(middleware1, middleware2);
In this example, middleware1 and middleware2 will be executed in the order they are passed to sequence().
Sources:
- Astro Middleware Guide (https://docs.astro.build/en/guides/middleware/)
- Astro API Reference (https://docs.astro.build/en/guides/middleware/#sequence)
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
meager folio
@sly epoch Can I pass a typescript based defineMiddleware into the sequence and if so, how
sly epochBOT
Let me check the knowledge base for you. One moment! :books:
Yes, you can pass TypeScript-based middleware defined with defineMiddleware() into the sequence() function. Here's how you can do it:
import { defineMiddleware, sequence } from "astro:middleware";
const middleware1 = defineMiddleware(async (context, next) => {
// Your middleware logic here
const response = await next();
return response;
});
const middleware2 = defineMiddleware(async (context, next) => {
// Your middleware logic here
const response = await next();
return response;
});
export const onRequest = sequence(middleware1, middleware2);
In this example, middleware1 and middleware2 are TypeScript-based middleware functions defined with defineMiddleware(). They are passed into the sequence() function, which will execute them in the order they are passed.
Source: Astro Middleware Guide (https://docs.astro.build/en/guides/middleware/)
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
meager folio
@sly epoch now how using definemiddleware can i use / access locals and specify the type
sly epochBOT
Let me check the knowledge base for you. One moment! :books:
In Astro, you can use the locals object to store and share request-specific information across endpoints and pages. This object can be accessed and manipulated inside middleware. Here's how you can do it with TypeScript type safety using defineMiddleware():
import { defineMiddleware } from "astro:middleware";
export const onRequest = defineMiddleware(({ locals, request }, next) => {
// You can access and modify locals here
locals.user = { name: "John Wick" };
locals.welcomeTitle = () => { return "Welcome back " + locals.user.name; };
// Return a Response or the result of calling `next()`
return next();
});
In this example, locals is automatically typed as an object. You can store any type of data inside locals: strings, numbers, and even complex data types such as functions and maps.
If you want to type the information inside Astro.locals for autocompletion inside .astro files and middleware code, you can declare a global namespace in the env.d.ts file:
/// <reference types="astro/client" />
declare namespace App {
interface Locals {
user: { name: string },
welcomeTitle: () => string,
orders: Map<string, object>
}
}
Then, inside the middleware file, you can take advantage of autocompletion and type safety.
Sources:
- Astro Middleware Guide (https://docs.astro.build/en/guides/middleware/)
- Astro API Reference (https://docs.astro.build/en/reference/api-reference/)
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
meager folio
@sly epoch and how can I still access context with locals
sly epochBOT
Let me check the knowledge base for you. One moment! :books:
In Astro, the context object is passed to the middleware function, and it includes the locals object. Here's how you can access both context and locals in TypeScript:
import { defineMiddleware } from "astro:middleware";
export const onRequest = defineMiddleware((context, next) => {
// Accessing context
const { locals, request } = context;
// You can now access and modify locals
locals.user = { name: "John Wick" };
locals.welcomeTitle = () => { return "Welcome back " + locals.user.name; };
// Return a Response or the result of calling `next()`
return next();
});
In this example, context is automatically typed and includes locals and request. You can destructure locals and request from context and use them in your middleware function.
Sources:
- Astro Middleware Guide (https://docs.astro.build/en/guides/middleware/)
- Astro API Reference (https://docs.astro.build/en/reference/api-reference/)