mathematic-incts:japi
A highly-modular (typescript-friendly)-framework agnostic library for serializing data to the JSON:API specification
Features
- This is the only typescript-compatible library that fully types the JSON:API specification and performs proper serialization.
- Zero dependencies.
- This is the only library with resource recursion.
- The modular framework laid out here highly promotes the specifications intentions:
- Using links is no longer obfuscated.
- Meta can truly be placed anywhere with possible dependencies laid out visibly.
- This library is designed to adhere to the specifications "never remove, only add" policy, so we will remain backwards-compatible.
Documentation
The documentation has everything that is covered here and more.
Installation
You can install ts-japi in your project's directory as usual:
npm install ts-japiGetting Started
There are fives classes that are used to serialize data (only one of which is necessarily required).
SerializerwithSerializerOptionsRelatorwithRelatorOptionsLinkerwithLinkerOptionsMetaizerPaginatorErrorSerializerwithErrorSerializerOptionsCachewithCacheOptions
You can check the documentation for a deeper insight into the usage.
Examples
You can check the examples and the
test folders to see some examples
(such as the ones below). You can check
this example to
see almost every option of
Serializer exhausted.
Serialization
The Serializer class is the
only class required for basic serialization.
The following example constructs the most basic
Serializer: (Note the await)
import { Serializer } from '../src';
import { User } from '../test/models';
import { getJSON } from '../test/utils/get-json';
const UserSerializer = new Serializer('users');
(async () => {
const user = new User('sample_user_id');
console.log('Output:', getJSON(await UserSerializer.serialize(user)));
// Output: {
// jsonapi: { version: '1.0' },
// data: {
// type: 'users',
// id: 'sample_user_id',
// attributes: {
// createdAt: '2020-05-20T15:44:37.650Z',
// articles: [],
// comments: []
// }
// }
// }
})();Links
The Linker class is used to
generate a normalized document link. Its methods are
not meant to be called. See the FAQ for reasons.
The following example constructs a
Linker for Users and Articles:
import { Linker } from '../src';
import { User, Article } from '../test/models';
import { getJSON } from '../test/utils/get-json';
// The last argument should almost always be an array or a single object type.
// The reason for this is the potential for linking several articles.
const UserArticleLinker = new Linker((user: User, articles: Article | Article[]) => {
return Array.isArray(articles)
? `https://www.example.com/users/${user.id}/articles/`
: `https://www.example.com/users/${user.id}/articles/${articles.id}`;
});
// ! The rest of this example is just to illustrate internal behavior.
(async () => {
const user = new User('sample_user_id');
const article = new Article('same_article_id', user);
console.log('Output:', getJSON(UserArticleLinker.link(user, article)));
// Output: https://www.example.com/users/sample_user_id/articles/same_article_id
})();Pagination
The Paginator class is used to
generate pagination links. Its methods are not
meant to be called.
The following example constructs a
Paginator:
import { Paginator } from '../src';
import { User, Article } from '../test/models';
import { getJSON } from '../test/utils/get-json';
const ArticlePaginator = new Paginator((articles: Article | Article[]) => {
if (Array.isArray(articles)) {
const nextPage = Number(articles[0].id) + 1;
const prevPage = Number(articles[articles.length - 1].id) - 1;
return {
first: `https://www.example.com/articles/0`,
last: `https://www.example.com/articles/10`,
next: nextPage <= 10 ? `https://www.example.com/articles/${nextPage}` : null,
prev: prevPage >= 0 ? `https://www.example.com/articles/${prevPage}` : null,
};
}
return;
});
// ! The rest of this example is just to illustrate internal behavior.
(async () => {
const user = new User('sample_user_id');
const article = new Article('same_article_id', user);
console.log('Output:', getJSON(ArticlePaginator.paginate([article])));
// Output: {
// first: 'https://www.example.com/articles/0',
// last: 'https://www.example.com/articles/10',
// prev: null,
// next: null
// }
})();Relationships
The Relator class is used to
generate top-level included data as well as
resource-level relationships.
Its methods are not meant to be called.
Relators may also take optional
Linkers (using the
linker option)
to define relationship links
and
related resource links.
The following example constructs a
Relator for Users and
Articles:
import { Serializer, Relator } from '../src';
import { User, Article } from '../test/models';
import { getJSON } from '../test/utils/get-json';
const ArticleSerializer = new Serializer<Article>('articles');
const UserArticleRelator = new Relator<User, Article>(
async (user) => user.getArticles(),
ArticleSerializer
);
// ! The rest of this example is just to illustrate some internal behavior.
(async () => {
const user = new User('sample_user_id');
const article = new Article('same_article_id', user);
User.save(user);
Article.save(article);
console.log('Output:', getJSON(await UserArticleRelator.getRelationship(user)));
// Output: { data: [ { type: 'articles', id: 'same_article_id' } ] }
})();Metadata
The Metaizer class is used to
construct generate metadata given some dependencies. There are several locations
Metaizer can be used:
ErrorSerializerOptions.metaizersRelatorOptions.metaizerSerializerOptions.metaizersLinkerOptions.metaizer
Like Linker, its methods are not
meant to be called.
The following example constructs a
Metaizer:
import { User, Article } from '../test/models';
import { Metaizer } from '../src';
import { getJSON } from '../test/utils/get-json';
// The last argument should almost always be an array or a single object type.
// The reason for this is the potential for metaizing several articles.
const UserArticleMetaizer = new Metaizer((user: User, articles: Article | Article[]) => {
return Array.isArray(articles)
? { user_created: user.createdAt, article_created: articles.map((a) => a.createdAt) }
: { user_created: user.createdAt, article_created: articles.createdAt };
});
// ! The rest of this example is just to illustrate internal behavior.
(async () => {
const user = new User('sample_user_id');
const article = new Article('same_article_id', user);
console.log('Output:', getJSON(UserArticleMetaizer.metaize(user, article)));
// Output: {
// user_created: '2020-05-20T15:39:43.277Z',
// article_created: '2020-05-20T15:39:43.277Z'
// }
})();Serializing Errors
The ErrorSerializer class
is used to serialize any object considered an error (the
attributes
option allows you to choose what attributes to use during serialization). Alternatively
(recommended), you can construct custom errors by extending the
JapiError class and use those
for all server-to-client errors.
The error serializer test includes an example of the alternative solution.
The following example constructs the most basic
ErrorSerializer: (Note
the lack of await)
import { ErrorSerializer } from '../src';
import { getJSON } from '../test/utils/get-json';
const PrimitiveErrorSerializer = new ErrorSerializer();
(async () => {
const error = new Error('badness');
console.log('Output:', getJSON(PrimitiveErrorSerializer.serialize(error)));
// Output: {
// errors: [ { code: 'Error', detail: 'badness' } ],
// jsonapi: { version: '1.0' }
// }
})();Caching
The Cache class can be placed in a
Serializer's
cache option.
Alternatively, setting that option to true will provide a default
Cache.
The default Cache uses the basic
Object.is
function to determine if input data are the same. If you want to adjust this, instantiate a new
Cache with a
resolver.
Deserialization
We stress the following: Given that there are many clients readily built to consume JSON:API endpoints (see here), we do not provide deserialization. In particular, since unmarshalling data is strongly related to the code it will be used in (e.g. React), tighter integration is recommended over an unnecessary abstraction.
Remarks
There are several model classes used inside TS:JAPI such as Resource and Relationships. These
models are used for normalization as well as traversing a JSON:API document. If you plan to fork
this repo, you can extend these models and reimplement them to create your own custom (non-standard,
extended) serializer.
FAQ
Why not just allow optional functions that return the internal
LinkClass (or just a URIstring)?
The Link class is defined to be as general as possible in case of changes in the specification. In
particular, the implementation of metadata and the types in our library rely on the generality of
the Link class. Relying on user arguments will generate a lot of overhead for both us and users
whenever the specs change.
Why does the
Metaclass exist if it is essentially just a plain object?
In case the specification is updated to change the meta objects in some functional way.
Due to compound documents, it is possible
to recurse through related resources via their
resource linkages and obtain
included resources beyond primary data relations.
This is should be done with caution (see
SerializerOptions.depth
and
this example)
For Developers
To get started in developing this library, run yarn install, yarn build and yarn test (in this
precise order) to assure everything is in working order.
Contributing
This project is maintained by the author, however contributions are welcome and appreciated. You can find TS:JAPI on GitHub: https://github.com/mathematic-inc/ts-japi
Feel free to submit an issue, but please do not submit pull requests unless it is to fix some issue. For more information, read the contribution guide.
License
Copyright © 2020 mathematic-inc.
Licensed under Apache 2.0.