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schema.Array

Creates a schema to normalize an array of schemas. If the input value is an Object instead of an Array, the normalized result will be an Array of the Object's values.

Note: The same behavior can be defined with shorthand syntax: [ mySchema ]

  • definition: required A singular schema that this array contains or a mapping of attribute values to schema.
  • schemaAttribute: optional (required if definition is not a singular schema) The attribute on each entity found that defines what schema, per the definition mapping, to use when normalizing. Can be a string or a function. If given a function, accepts the following arguments: _ value: The input value of the entity. _ parent: The parent object of the input array. * key: The key at which the input array appears on the parent object.
tip

For unbounded collections with string keys, use schema.Values

tip

Make it mutable with Collections

Instance Methods​

  • define(definition): When used, the definition passed in will be merged with the original definition passed to the Array constructor. This method tends to be useful for creating circular references in schema.

Usage​

To describe a simple array of a singular entity type:

Fixtures
GET /users
[{"id":"123","name":"Jim"},{"id":"456","name":"Jane"}]
▶Users.tsx
export class User extends Entity {
  id = '';
  name = '';
  pk() {
    return this.id;
  }
}
export const getUsers = new RestEndpoint({
  path: '/users',
  schema: new schema.Array(User),
});
function UsersPage() {
  const users = useSuspense(getUsers);
  return (
    <div>
      {users.map(user => (
        <div key={user.pk()}>{user.name}</div>
      ))}
    </div>
  );
}
render(<UsersPage />);
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Polymorphic types​

If your input data is an array of more than one type of entity, it is necessary to define a schema mapping.

note

If your data returns an object that you did not provide a mapping for, the original object will be returned in the result and an entity will not be created.

string schemaAttribute​

Fixtures
GET /feed
[{"id":1,"type":"link","url":"https://ntucker.true.io","title":"Nate site"},{"id":10,"type":"post","content":"good day!"}]
▶api/Feed.ts
export abstract class FeedItem extends Entity {
  readonly id: number = 0;
  declare readonly type: 'link' | 'post';
  pk() {
    return `${this.id}`;
  }
}
export class Link extends FeedItem {
  readonly type = 'link' as const;
  readonly url: string = '';
  readonly title: string = '';
}
export class Post extends FeedItem {
  readonly type = 'post' as const;
  readonly content: string = '';
}
export const getFeed = new RestEndpoint({
  path: '/feed',
  schema: new schema.Array(
    {
      link: Link,
      post: Post,
    },
    'type',
  ),
});
▶FeedList.tsx
import { getFeed, Link, Post } from './api/Feed';

function FeedList() {
  const feedItems = useSuspense(getFeed);
  return (
    <div>
      {feedItems.map(item =>
        item.type === 'link' ? (
          <LinkItem link={item} key={item.pk()} />
        ) : (
          <PostItem post={item} key={item.pk()} />
        ),
      )}
    </div>
  );
}
function LinkItem({ link }: { link: Link }) {
  return <a href={link.url}>{link.title}</a>;
}
function PostItem({ post }: { post: Post }) {
  return <div>{post.content}</div>;
}
render(<FeedList />);
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function schemaAttribute​

The return values should match a key in the definition. Here we'll show the same behavior as the 'string' case, except we'll append an 's'.

Fixtures
GET /feed
[{"id":1,"type":"link","url":"https://ntucker.true.io","title":"Nate site"},{"id":10,"type":"post","content":"good day!"}]
▶api/Feed.ts
export abstract class FeedItem extends Entity {
  readonly id: number = 0;
  declare readonly type: 'link' | 'post';
  pk() {
    return `${this.id}`;
  }
}
export class Link extends FeedItem {
  readonly type = 'link' as const;
  readonly url: string = '';
  readonly title: string = '';
}
export class Post extends FeedItem {
  readonly type = 'post' as const;
  readonly content: string = '';
}
export const getFeed = new RestEndpoint({
  path: '/feed',
  schema: new schema.Array(
    {
      links: Link,
      posts: Post,
    },
    (input: Link | Post, parent, key) => `${input.type}s`,
  ),
});
▶FeedList.tsx
import { getFeed, Link, Post } from './api/Feed';

function FeedList() {
  const feedItems = useSuspense(getFeed);
  return (
    <div>
      {feedItems.map(item =>
        item.type === 'link' ? (
          <LinkItem link={item} key={item.pk()} />
        ) : (
          <PostItem post={item} key={item.pk()} />
        ),
      )}
    </div>
  );
}
function LinkItem({ link }: { link: Link }) {
  return <a href={link.url}>{link.title}</a>;
}
function PostItem({ post }: { post: Post }) {
  return <div>{post.content}</div>;
}
render(<FeedList />);
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