How do I render a page correctly with prerender false? The page has logic with session that breaks if it's rendered in build. So how do I fix the images using export const prerender = false;
#prerender false
young cedar
gusty galleonBOT
Hi @young cedar. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:
To render a page with prerender = false, you need to add export const prerender = false to the top of your Astro or JavaScript file. This will ensure that the page or endpoint is server-rendered, which is useful for pages with session logic that may break if pre-rendered during build time.
Here's an example of how to do this in an Astro file:
---
export const prerender = false
// Your session logic here...
---
<!-- Your HTML here... -->
And here's an example for a JavaScript file:
export const prerender = false;
export async function GET() {
// Your session logic here...
let number = Math.random();
return { body: JSON.stringify({ number, message: `Here's a random number: ${number}` }), };
}
However, if you're experiencing issues with images when using prerender = false, it might be due to a known bug with Vercel's includeFiles being ignored for hybrid API routes with prerender = false (source (https://github.com/withastro/astro/issues/8402)). Unfortunately, there's no provided solution for this issue in the extracts. You might want to check the status of this issue on Astro's GitHub page for any updates or workarounds.
Remember, when using prerender = false, the prerender feature only supports a subset of valid JavaScript. Be sure to use exactly export const prerender = false so that Astro's compiler can detect this directive at build time. Variables, let, and var declarations are not supported (source (https://docs.astro.build/en/reference/errors/invalid-prerender-export/)).
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
young cedar
@gusty galleon so, what do I do with the images with prerender false?
import { Image } from 'astro:assets';
import personBoardLight from "../assets/binfografia-light.png";
import personBoardDark from "../assets/binfografia-dark.png";
<Image class="mx-1 my-auto w-2/3 object-cover hidden dark:block"
src={personBoardDark}
width={512}
alt="Person"
/>
For instance.
gusty galleonBOT
Let me check the knowledge base for you. One moment! :books:
When using prerender = false, you can still use the Image component from astro:assets to handle images. However, you need to ensure that the images are correctly imported and used within the component. Here's an example based on your code:
---
import { Image } from 'astro:assets';
import personBoardLight from "../assets/binfografia-light.png";
import personBoardDark from "../assets/binfografia-dark.png";
export const prerender = false;
---
<Image class="mx-1 my-auto w-2/3 object-cover hidden dark:block"
src={personBoardDark}
width={512}
alt="Person"
/>
This code will import the images and use them in the Image component, even when prerender = false is set.
However, if you're deploying on Vercel and facing issues with images not being found or loaded, it might be due to a known bug where Vercel's includeFiles is ignored for hybrid API routes with prerender = false (source (https://github.com/withastro/astro/issues/8402)). Unfortunately, there's no provided solution for this issue in the extracts. You might want to check the status of this issue on Astro's GitHub page for any updates or workarounds.
Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:
young cedar
@gusty galleon const cookie = Astro.request.headers.get('cookie');
does this line work with prerender true?
gusty galleonBOT
Let me check the knowledge base for you. One moment! :books:
No, the line const cookie = Astro.request.headers.get('cookie'); will not work with prerender = true.
When a page is pre-rendered (prerender = true), it is generated at build time and served as static HTML. This means it doesn't have access to request-specific data like cookies, because there's no request happening at the time the page is being generated.
If you need to access cookies, you should use prerender = false to ensure the page is server-rendered, which does have access to request-specific data. Alternatively, you can use Astro.cookies to read and manipulate cookies in server-side rendering mode (source (https://docs.astro.build/en/reference/api-reference/#astrocookies)).
Here's an example of how to use Astro.cookies:
---
// Check if a cookie exists
if (!Astro.cookies.has('cookieName')) {
// Set a default value if it doesn’t exist
Astro.cookies.set('cookieName', 'defaultValue');
}
// Get the value of the cookie
const cookieValue = Astro.cookies.get('cookieName').value;
---
<!-- Your HTML here... -->