feat: use the first image of an article as og:image

This commit is contained in:
grassblock 2025-05-24 21:40:30 +08:00
parent 5ef4dda34e
commit db09d3bf88
3 changed files with 46 additions and 6 deletions

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@ -3,7 +3,7 @@ title: 'My Terminal Setup'
description: 'A walkthrough of my current terminal configuration'
pubDate: '2025-06-08'
---
![cover](./demo.png)
Here's my current terminal setup:
- Shell: ZSH with Oh My Zsh

View file

@ -3,12 +3,9 @@ import Layout from '../../layouts/Layout.astro';
import { getCollection, getEntry } from 'astro:content';
import Comments from "../../components/Comments.astro";
import {getImage} from "astro:assets";
import { unified } from "unified";
import { select } from "unist-util-select";
import remarkMdx from "remark-mdx";
import remarkParse from "remark-parse";
import {siteConfig} from "../../config";
import ReplyViaEmail from "../../components/ReplyViaEmail.astro";
import { ExtractFirstImage } from '../../plugins/extract-images';
export async function getStaticPaths() {
const blogEntries = await getCollection('posts');
@ -36,8 +33,9 @@ let matchedImage_src;
if (matchedImage && !customFeaturedImage) {
matchedImage_src = await getImage({src: featuredImages[matchedImage], format: 'webp'}) || null;
}
const firstImageURL = await ExtractFirstImage(Content,Astro.url.origin)
const cover = customFeaturedImage || matchedImage_src?.src || `/post/${slug}/featured.png` || '';
const cover = customFeaturedImage || matchedImage_src?.src || firstImageURL || `/post/${slug}/featured.png` || '';
---
<Layout

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@ -0,0 +1,42 @@
import {loadRenderers} from "astro:container";
import {getContainerRenderer as getMDXRenderer} from "@astrojs/mdx";
import {experimental_AstroContainer as AstroContainer} from "astro/container";
import {transform, walk} from "ultrahtml";
export async function ExtractFirstImage(Content, baseUrl = '') {
// Load MDX renderer. Other renderers for UI frameworks (e.g. React, Vue, etc.) would need adding here if you were using those.
const renderers = await loadRenderers([getMDXRenderer()]);
// Create a new Astro container that we can render components with.
// See https://docs.astro.build/en/reference/container-reference/
const container = await AstroContainer.create({renderers});
// Use the Astro container to render the content to a string.
const rawContent = await container.renderToString(Content);
let firstImageUrl = null;
// The transform function returns a promise, so we need to await it
await transform(rawContent.replace(/^<!DOCTYPE html>/, ''), [
async (node) => {
await walk(node, (node) => {
if (node.name === "img" && node.attributes.src) {
// Store the first image URL we find
if (!firstImageUrl) {
firstImageUrl = node.attributes.src.startsWith("/")
? baseUrl + node.attributes.src
: node.attributes.src;
}
// Still update the src attribute if needed
if (node.attributes.src.startsWith("/")) {
node.attributes.src = baseUrl + node.attributes.src;
}
}
});
return node;
}
]);
// Return the URL value, not a Promise
return firstImageUrl;
}