查询内容

EmDash 提供在 Astro 页面与组件中获取内容的查询函数，遵循 Astro 的 live content collections 模式，返回带错误处理的结构化结果。

查询函数

EmDash 导出两个主要查询函数：

从 emdash 导入：

import { getEmDashCollection, getEmDashEntry } from "emdash";

获取全部条目

使用 getEmDashCollection 加载某类型的所有条目：

---
import { getEmDashCollection } from "emdash";

const { entries: posts, error } = await getEmDashCollection("posts");

if (error) {
  console.error("Failed to load posts:", error);
}
---

<ul>
  {posts.map((post) => (
    <li>{post.data.title}</li>
  ))}
</ul>

按语言区域筛选

启用 i18n 后，可用 locale 获取指定语言内容：

const { entries: frenchPosts } = await getEmDashCollection("posts", {
	locale: "fr",
	status: "published",
});

const { entries: localizedPosts } = await getEmDashCollection("posts", {
	locale: Astro.currentLocale,
	status: "published",
});

单条查询将 locale 作为第三个参数传入：

const { entry: post } = await getEmDashEntry("posts", "my-post", {
	locale: Astro.currentLocale,
});

省略 locale 时默认使用当前请求的语言区域；若无翻译则走 回退链。

按状态筛选

仅已发布或仅草稿：

const { entries: published } = await getEmDashCollection("posts", {
	status: "published",
});

const { entries: drafts } = await getEmDashCollection("posts", {
	status: "draft",
});

限制条数

const { entries: recentPosts } = await getEmDashCollection("posts", {
	status: "published",
	limit: 5,
});

按分类体系筛选

按分类、标签或自定义术语：

const { entries: newsPosts } = await getEmDashCollection("posts", {
	status: "published",
	where: { category: "news" },
});

const { entries: jsPosts } = await getEmDashCollection("posts", {
	status: "published",
	where: { tag: "javascript" },
});

const { entries: featuredNews } = await getEmDashCollection("posts", {
	status: "published",
	where: { category: ["news", "featured"] },
});

对同一分类字段提供多个值时，where 使用 OR 逻辑。

错误处理

在需要可靠性的场景始终检查 error：

const { entries: posts, error } = await getEmDashCollection("posts");

if (error) {
	console.error("Failed to load posts:", error);
	return new Response("Server error", { status: 500 });
}

获取单条条目

getEmDashEntry 按 ID 或 slug 加载一条：

---
import { getEmDashEntry } from "emdash";
import { PortableText } from "emdash/ui";

const { slug } = Astro.params;
const { entry: post, error } = await getEmDashEntry("posts", slug);

if (error) {
  return new Response("Server error", { status: 500 });
}

if (!post) {
  return Astro.redirect("/404");
}
---

<article>
  <h1>{post.data.title}</h1>
  <PortableText value={post.data.content} />
</article>

返回类型

interface EntryResult<T> {
	entry: ContentEntry<T> | null;
	error?: Error;
	isPreview: boolean;
}

interface ContentEntry<T> {
	id: string;
	data: T;
	edit: EditProxy;
}

预览模式

中间件会校验 _preview；查询函数无需额外参数即可返回草稿：

---
import { getEmDashEntry } from "emdash";

const { slug } = Astro.params;

const { entry, isPreview, error } = await getEmDashEntry("posts", slug);

if (error) {
  return new Response("Server error", { status: 500 });
}

if (!entry) {
  return Astro.redirect("/404");
}
---

{isPreview && (
  <div class="preview-banner">
    预览中。此内容尚未发布。
  </div>
)}

<article>
  <h1>{entry.data.title}</h1>
  <PortableText value={entry.data.content} />
</article>

可视化编辑

<article {...entry.edit}>
  <h1 {...entry.edit.title}>{entry.data.title}</h1>
  <div {...entry.edit.content}>
    <PortableText value={entry.data.content} />
  </div>
</article>

排序

getEmDashCollection 不保证顺序，请在模板中排序：

const { entries: posts } = await getEmDashCollection("posts", {
	status: "published",
});

const sorted = posts.sort(
	(a, b) => (b.data.publishedAt?.getTime() ?? 0) - (a.data.publishedAt?.getTime() ?? 0),
);

posts.sort((a, b) => a.data.title.localeCompare(b.data.title));
posts.sort((a, b) => (a.data.order ?? 0) - (b.data.order ?? 0));
posts.sort(() => Math.random() - 0.5);

TypeScript

npx emdash types

import { getEmDashCollection, getEmDashEntry } from "emdash";
import type { Post } from "../.emdash/types";

const { entries: posts } = await getEmDashCollection<Post>("posts");
const { entry: post } = await getEmDashEntry<Post>("posts", "my-post");

静态与服务器渲染

静态（预渲染）

---
import { getEmDashCollection, getEmDashEntry } from "emdash";

export async function getStaticPaths() {
  const { entries: posts } = await getEmDashCollection("posts", {
    status: "published",
  });

  return posts.map((post) => ({
    params: { slug: post.data.slug },
  }));
}

const { slug } = Astro.params;
const { entry: post } = await getEmDashEntry("posts", slug);
---

服务器渲染

---
export const prerender = false;

import { getEmDashEntry } from "emdash";

const { slug } = Astro.params;
const { entry: post, error } = await getEmDashEntry("posts", slug);

if (error) {
  return new Response("Server error", { status: 500 });
}

if (!post) {
  return new Response(null, { status: 404 });
}
---

性能

缓存

---
const { entries: posts } = await getEmDashCollection("posts", {
  status: "published",
});

Astro.response.headers.set("Cache-Control", "public, max-age=300");
---

避免重复查询

---
import { getEmDashCollection } from "emdash";
import PostList from "../components/PostList.astro";
import Sidebar from "../components/Sidebar.astro";

const { entries: posts } = await getEmDashCollection("posts", {
  status: "published",
});

const featured = posts.filter((p) => p.data.featured);
const recent = posts.slice(0, 5);
---

<PostList posts={featured} />
<Sidebar posts={recent} />

下一步

• Create a Blog — 搭建完整博客
• Taxonomies — 按分类与标签筛选
• Working with Content — 后台 CRUD
• Internationalization — 多语言内容