This introduction to content material collections in Astro is excepted from Unleashing the Energy of Astro, out there now on SitePoint Premium.

To utilize content material collections, Astro designates a particular folder: src/content material. Subsequently, we are able to create subfolders inside this location, every producing particular person content material collections. For example, we may create collections comparable to src/content material/dev-blog and src/content material/corporate-blog.

Every content material assortment may be configured in a config file—/src/content material/config.js (or .ts)—the place we now have the choice to make use of assortment schemas utilizing Zod.

Zod is a “TypeScript-first schema validation with static sort inference” that’s built-in into Astro. Right here’s an instance of how this might take form:

// src/content material/config.js
import { z, defineCollection } from 'astro:content material';

const devBlogCollection = defineCollection({
  schema: z.object({
    title: z.string(),
    writer: z.string().default('The Dev Group'),
    tags: z.array(z.string()),
    date: z.date(),
    draft: z.boolean().default(true),
    description: z.string(),
  }),
});

const corporateBlogCollection = defineCollection({
  schema: z.object({
    title: z.string(),
    writer: z.string(),
    date: z.date(),
    featured: z.boolean(),
    language: z.enum(['en', 'es']),
  }),
});

export const collections = {
  devblog: devBlogCollection,
  corporateblog: corporateBlogCollection,
};

Within the code above, we’re defining two content material collections—one for a “developer weblog” and one for a “company weblog”. The defineCollection technique permits us to create a schema for any given assortment. For the “developer weblog”, we’re making a schema the place the articles for this weblog class should have a title (string), writer (string defaulting to “The Dev Group”), tags (array of strings), date (date sort), draft (Boolean defaulting to true) and an outline (string).

For the “company weblog”, our schema is slightly bit completely different: we now have a string for each the title and the writer. Date (information sort) can also be going to be required by the content material, in addition to the featured (Boolean) flag and a language (enum), which might both be set to en or es.

Lastly, we’re exporting a collections object with two properties, devblog and corporateblog. These will probably be used afterward.

---
title: 'Purchase!!'
writer: 'Jack from Advertising'
date: 2023-07-19
featured: true
language: 'en'
---

# Some Advertising Promo

That is the very best product!

Slug Creation

Astro will routinely generate slugs for posts primarily based on the file title. For instance, the slug for first-post.md will probably be first-post. Nevertheless, if we offer a slug entry in our frontmatter, Astro will respect that and use our customized slug.

Keep in mind that the properties specified within the export const collections object should match the folder names the place the content material goes to stay. (Additionally word that they’re case delicate!)

Querying Information

As soon as we now have all of the Markdown recordsdata in place (in our case, that will be beneath src/content material/devblog and src/content material/corporateblog) and our config.js file prepared, we are able to begin to question information from the collections, which is a simple course of:

---
import { getCollection } from 'astro:content material';
const allDevPosts = await getCollection('devblog');
const allCorporatePosts = await getCollection('corporateblog');
---
<pre>{JSON.stringify(allDevPosts)}</pre>
<pre>{JSON.stringify(allCorporatePosts)}</pre>

As seen above, the getCollection technique can be utilized to retrieve all of the entries from a given assortment (once more, referencing the exported assortment names from earlier). Within the instance above, we retrieve all of the posts from each the “developer weblog” (devblog) and from the “company weblog” (corporateblog). Within the template, we merely return the uncooked information utilizing JSON.stringify().

We must also study the info that’s being displayed through JSON.stringify(), and we should always take word that, aside from the frontmatter information, we additionally get an id, a slug, and a physique property returned to make use of the place the latter accommodates the publish’s content material.

We will additionally filter for drafts or posts written in a selected language within the frontmatter part by iterating by way of all articles like this:

import { getCollection } from 'astro:content material';

const spanishEntries = await getCollection('corporateblog', ({ information }) => {
  return information.language === 'es';
});

getCollection returns all of the posts, however we are able to additionally use getEntry to return a single entry from inside a group:

import { getEntry } from 'astro:content material';

const singleEntry = await getEntry('corporateblog', 'pr-article-1');

getCollection vs getEntries

Whereas there are two methods to return a number of posts from collections, there’s a delicate distinction between the 2 of them. getCollection() retrieves an inventory of content material assortment entries by assortment title, whereas getEntries() retrieves a number of assortment entries from the identical assortment.

The Astro documentation provides the instance of getEntries() getting used to retrieve content material when utilizing reference entities (for instance, an inventory of associated posts).

The idea of associated posts is the place we are able to reference an array of posts from a group. This may be achieved by including the next to the schema when utilizing the defineCollection technique:

import { defineCollection, reference, z } from 'astro:content material';

const devblog = defineCollection({
  schema: z.object({
    title: z.string(),
    relatedPosts: z.array(reference('weblog')),
  }),
});

Within the code above, we’re additionally importing reference and utilizing that when including relatedPosts to our schema. (Observe that we are able to name this no matter we would like, comparable to recommendedPosts or followupPosts.)

To make use of these relatedPosts, the suitable slug values needs to be added to the frontmatter a part of the Markdown:

title: "This can be a publish"
relatedPosts:

- A associated publish # `src/content material/devblog/a-related-post.md

Reference entities are outlined within the config.js file for the content material assortment and use the reference technique from Zod:

const weblog = defineCollection({
  sort: 'content material',
  schema: z.object({
    title: z.string(),
    relatedPosts: z.array(reference('weblog')).non-obligatory(),
    writer: reference('writer'),
  }),
});

const writer = defineCollection({
  sort: 'information',
  schema: z.object({
    title: z.string(),
  }),
});

Additionally, discover the utilization of sort: 'content material' and sort: 'information'. On this case, the gathering encompasses each content material authoring codecs comparable to Markdown (sort: 'content material') and information codecs like JSON or YAML (sort: 'information').

Displaying the Content material

Now that we all know easy methods to question information, let’s talk about easy methods to truly show it in a formatted means. Astro offers a handy technique referred to as render() to render the complete content material of the Markdown right into a built-in Astro element referred to as <Content material />. How we construct and show the content material can also be going to be pushed by whether or not we now have static website technology or server-side rendering mode.

For pre-rendering, we are able to use the getStaticPaths() technique:

// /src/pages/posts/[...slug].astro
---
import { getCollection } from 'astro:content material';

export async perform getStaticPaths() {
  const blogEntries = await getCollection('weblog');
  return blogEntries.map(entry => ({
    params: { slug: entry.slug }, props: { entry },
  }));
}

const { entry } = Astro.props;
const { Content material } = await entry.render();
---
<h1>{entry.information.title}</h1>
<Content material />

Within the code above, we’re utilizing getStaticPaths(). (We lined this technique within the second tutorial of this sequence as a solution to cater for dynamic routes.) We then depend on Astro.props to seize the entry, which goes to be an object that accommodates the metadata in regards to the entry, an id, a slug, and a render() technique. This technique is answerable for rendering the Markdown entry to HTML within the Astro template, and it does so by making a <Content /> element. What’s wonderful about that is that every one we have to do now could be add the <Content material /> element to our template and we’ll be capable of see the Markdown content material rendered into HTML.

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