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Version: 0.17

What's new in v0.17

This is a distillation of what's new in Orbit v0.17, intended as a reference for developers who need to upgrade their apps and libraries from v0.16.

If you're brand new to Orbit yourself, you may wish to skip this section in order to explore Orbit's latest features in a broader context.

New Site + API Reference​

v0.17 is Orbit's first release that comes with API docs for all its packages. These docs are generated by TypeDoc from Orbit's typings and code annotations. Although a bit sparse for now, this reference should only improve with time and help from the community. Contributions will be most appreciated!

Improved, strict typings throughout​

The TypeScript in all of Orbit's packages has been improved to the extent that it is now all compiled with the strict flag. This has allowed us to refactor more confidently, improve our documentation, and provide a better developer experience all around.

Extraction of @orbit/records from @orbit/data​

As part of the push to improve typings, it became clear that @orbit/data contains a number of interfaces and classes that could prove useful for any type of data, not just records. Thus, record-specific types and classes were extracted into a new package: @orbit/records.

Please review the exports from @orbit/records for a complete listing of classes, interfaces, and other types that have been moved to this new package.

Be aware that several exports have been renamed to be explicit about being record-specific. For instance, Schema is now RecordSchema, so you'll want to make this refactor:

- import { Schema } from '@orbit/data';
+ import { RecordSchema } from '@orbit/records';

Apologies for this breaking change and the refactoring it requires. We're trying to settle the scope of each package prior to v1.0.

Breaking change

Please review all your direct imports from @orbit/data and replace them as needed with imports from @orbit/records.

Singular vs. multi-expression queries​

In v0.16, each Query could only have a single expression:

// v0.16
export interface Query {
id: string;
expression: QueryExpression;
options?: any;

Now, Query is typed as follows, with expressions that can be singular or an array of query expressions:

// v0.17
export interface Query<QE extends QueryExpression> {
id: string;
expressions: QE | QE[];
options?: RequestOptions;

This allows sources, such as JSONAPISource, to optionally perform these expressions in parallel, which it does now by default.

Now that queries can contain multiple expressions just like transforms can contain multiple operations, there needs to be a clear and consistent way to build them. And likewise, the expectation needs to be clear about the form in which results should be returned.

Here's a single expression to a query builder, which can be expected to return a single result:

const earth = await source.query((q) =>
q.findRecord({ type: 'planet', id: 'earth' })

That same expression could be passed in an array, which will cause results to be returned in an array:

const [earth] = await source.query((q) => [
q.findRecord({ type: 'planet', id: 'earth' })

And of course, that array could be expanded to include more than one expression:

const [earth, jupiter, saturn] = await source.query((q) => [
q.findRecord({ type: 'planet', id: 'earth' }),
q.findRecord({ type: 'planet', id: 'jupiter' }),
q.findRecord({ type: 'planet', id: 'saturn' })

As mentioned above, this query may be handled with 3 parallel requests, but will only resolve when all have completed successfully.

Breaking change

Although most developers typically do not interact with queries directly, if you do it's important to note the change from expression -> expressions.

Singular vs. multi-operation transforms​

All the patterns mentioned above for queries also apply to transforms.

A single operation provided to a transform builder will return a single result:

const earth = await source.update((t) =>
t.addRecord({ type: 'planet', id: 'earth' })

The same expression passed in an array will cause results to be returned in an array:

const [earth] = await source.update((t) => [
t.addRecord({ type: 'planet', id: 'earth' })

And as before, multi-operation transforms will produce an array of results:

const [earth, jupiter, saturn] = await source.update((t) => [
t.addRecord({ type: 'planet', id: 'earth' }),
t.addRecord({ type: 'planet', id: 'jupiter' }),
t.addRecord({ type: 'planet', id: 'saturn' })

The Transform interface has changed subtly such that operations can now be singular or an array, to parallel Query#expressions:

// v0.17
export interface Transform<O extends Operation> {
id: string;
operations: O | O[];
options?: RequestOptions;
Breaking changes

The change that allows Transform's operations to be singular is breaking. You may wish to use a utility function such as toArray to interact with operations uniformly as an array.

Also note that, in v0.16, calling update with a single operation in an array would return a singular result. It will now return that same result as the single member of an array.

Full vs. data-only responses​

All requests (queries and updates) can now be made with a { fullResponse: true } option to receive responses as a FullResponse. Full responses include the following members:

  • data - the primary data that would be returned without the fullResponse option

  • details - response details particular to the source. For a MemorySource, this will include applied and inverse operations. For a JSONAPISource, this will include Response objects and documents.

  • transforms - these are the transforms applied as a result of this request. They are always emitted with a transform event, which hooks into Orbit's sync flow.

  • sources - a map of source-specific response details from downstream sources that were engaged in fulfilling this request.

It's now up to you just how much of this information you want at the call site. The following requests will be handled the same internally:

// Just the data
const planets = await source.query((q) => q.findRecords('planet'));

// All the details
const { data, details, transforms, sources } = await source.query(
(q) => q.findRecords('planet'),
{ fullResponse: true }

Improved response typings​

Speaking of responses, it's now possible to type them using TypeScript generics instead of relying on type coercion (i.e. response as Type).

Standard data requests can type the response data:

// query<RequestData>(queryOrExpressions, options, id?): Promise<RequestData>
const planets = await source.query<Planet[]>((q) => q.findRecords('planet'));

Full data requests can type the response data, details, and operation:

// query<RequestData, RequestDetails, RequestOperation>(queryOrExpressions, options, id?): Promise<FullResponse<RequestData, RequestDetails, RequestOperation>>;
const { data, details, transforms, sources } = await source.query<
>((q) => q.findRecords('planet'), { fullResponse: true });

Deprecation of Pullable and Pushable interfaces​

Now that responses can include full processing details, everything that was unique to the pull and push methods on source is redundant. The Pullable and Pushable interfaces have been deprecated to focus on the more capable Queryable and Updatable interfaces for making requests.

One common use case for pull / push was restoring from backup:

const transform = await backup.pull((q) => q.findRecords());
await memory.push(transform);

This can be achieved as follows with query / sync (or update):

const allRecords = await backup.query((q) => q.findRecords());
await memory.sync((t) => => t.addRecord(r)));

And if you do want access to the transforms that result from a request, specify that you want a full response:

const { transforms } = await source.update((t) => [
t.addRecord(type: 'planet', attributes: { name: 'Earth' }),
t.addRecord(type: 'planet', attributes: { name: 'Jupiter' })
{ fullResponse: true }

Transform buffers for faster cache processing​

Record-cache-based sources that interact with browser storage have had performance issues when dealing with large datasets, especially when paired with read/write heavy processors that ensure relationship tracking and correctness. A new paradigm has been developed, the RecordTransformBuffer, that acts as a memory buffer for these operations.

For now, using this buffer is opt-in, with the { useBuffer: true } option:

await indexeddbSource.update((t) => [
t.addRecord(type: 'planet', attributes: { name: 'Earth' }),
t.addRecord(type: 'planet', attributes: { name: 'Jupiter' })
{ useBuffer: true }

Performance improvements are quite promising, and stability seems solid.


The only edge cases we've found to be concerned about are related to cascading deletes, which are triggered when record relationships are defined with dependent: delete. In those cases, the cascade may not be as complete in the buffer as in the actual cache, so we recommend avoiding transform buffers for now.

New serializers​

Concepts of serialization have, up until now, been very specific to usage by the JSONAPISource, and particularly the JSONAPISerializer class. This class has been deprecated and replaced with a series of composable serializers all build upon a simple and flexible Serializer interface. This interface, as well as some serializers for primitives (booleans, dates, date-times, etc.) have been published in a new package, @orbit/serializers.

New serializers particular to JSON:API have also been added to @orbit/jsonapi, including:

  • JSONAPIDocumentSerializer
  • JSONAPIResourceSerializer
  • JSONAPIResourceIdentitySerializer
  • JSONAPIResourceFieldSerializer
  • JSONAPIOperationSerializer
  • JSONAPIOperationsDocumentSerializer

These new serializers remove some of the default behaviors present in v0.16 - resource fields and types in documents are no longer dasherized and pluralized, but are left "as is" in camelized form. This lines up with the new recommendations for the JSON:API spec and creates much less work by default.

Each of these classes can be overridden to provide custom serialization behavior. You could then provide those custom classes when creating your source:

const source = new JSONAPISource({
serializerClassFor: buildSerializerClassFor({
[JSONAPISerializers.Resource]: MyCustomResourceSerializer,
[JSONAPISerializers.ResourceType]: MyCustomResourceTypeSerializer

Alternatively, you can use the standard serializers but provide custom settings for those serializers. For example, here are settings that match the previous default serialization options:

const source = new JSONAPISource({
serializerSettingsFor: buildSerializerSettingsFor({
sharedSettings: {
// Optional: Custom `pluralize` / `singularize` inflectors that know about
// your app's unique data.
inflectors: {
pluralize: buildInflector(
{ person: 'people' }, // custom mappings
(input) => `${input}s` // naive pluralizer, specified as a fallback
singularize: buildInflector(
{ people: 'person' }, // custom mappings
(arg) => arg.substring(0, arg.length - 1) // naive singularizer, specified as a fallback
// Serialization settings according to the type of serializer
settingsByType: {
[JSONAPISerializers.ResourceField]: {
serializationOptions: { inflectors: ['dasherize'] }
[JSONAPISerializers.ResourceFieldParam]: {
serializationOptions: { inflectors: ['dasherize'] }
[JSONAPISerializers.ResourceFieldPath]: {
serializationOptions: { inflectors: ['dasherize'] }
[JSONAPISerializers.ResourceType]: {
serializationOptions: { inflectors: ['pluralize', 'dasherize'] }
[JSONAPISerializers.ResourceTypePath]: {
serializationOptions: { inflectors: ['pluralize', 'dasherize'] }

New validators​

A common source of problems for Orbit developers has been using data that is malformed or doesn't align with a schema's expectations. This can cause confusing errors during processing by a cache or downstream source.

To address this problem, we're introducing "validators", which are shipped in a new package @orbit/validators that includes some validators for primitive types. Validators that are record-specific have also been included in @orbit/records.

By default, each source will build its own set of validators and use them automatically. You can instead share a common set of validators via the validatorFor settings. And you can opt-out of using validators entirely by configuring your sources with { autoValidate: false }.

Record normalizers​

When building queries and transforms, some scenarios have been more tedious than necessary: identifying records by a key instead of id, for instance, or using a model class from a lib like ember-orbit to reference a record instead of its json identity.

A new abstraction has been added to make query and transform builders more flexible: record normalizers. Record normalizers implement the RecordNormalizer interface and convert record identities and/or data into a normalized form.

The new base normalizer now allows { type, key, value } to be used anywhere that { type, id } identities can be used, which significantly reduces the annoyance of working with remote keys.

Synchronous change tracking in memory forks​

Previously, memory source forks behaved precisely like other memory sources: every trackable update applied at the source level (and thus async). Now, the default (but overrideable) behavior is to track changes at the cache level in forks. Thus synchronous changes can be made to a forked cache and then merged back into the base source.

This improves the DX for the most common use case for forks: editing form data in isolation before merging coalesced changes back to the base. For example:

// (sync) fork a base memory source
let fork = source.fork();

// (sync) add jupiter synchronously to the forked source's cache
fork.cache.update((t) =>
type: 'planet',
id: 'jupiter',
attributes: { name: 'Jupiter' }

// (async) merge changes from the fork back to its base
await source.merge(fork);

// (async) jupiter should now be in the base source (as well as its cache)
let jupiter = await source.query((q) =>
q.findRecord({ type: 'planet', id: 'jupiter' })

If you want to continue to track changes only at the source-level and have merge work only with those changes, pass the following configuration setting when you fork a source:

let fork = source.fork({
cacheSettings: { trackUpdateOperations: false }

This will prevent update tracking at the cache level and will signal to merge that only transforms applied at the source-level should be merged.

New memory cache capabilities​

In addition to the above improvements to memory sources, v0.17 also adds the following methods to MemoryCache:

  • fork - creates a new cache based on this one.
  • merge - merges changes from a forked cache back into this cache.
  • rebase - resets this cache's state to that of its base and then replays any update operations.

Memory cache forking / merging / rebasing is a lighter-weight way of "branching" changes, that can ultimately be merged back into a source. Cache-level forking can be paired with source-level forking for a lot of flexibility and power.

Debug mode​

A new debug setting has been added to the Orbit global, that toggles between using a more verbose, developer-friendly "debug" mode of Orbit vs. a leaner, more performant production mode.

Debug mode is enabled by default. Some standard features of debug mode include deprecation warnings and extra debug-friendly verifications and messaging.

To disable debug mode:

import { Orbit } from '@orbit/core';

// disable debug mode
Orbit.debug = false;

For several releases in the v0.17 beta cycle, debug mode was used to control whether validators would be created by default. This is no longer the case β€” validators will now always be used within sources and caches unless disabled using the autoValidate: false setting described above. This provides more fine-grained control over validation settings throughout your app and its sources.

Increased reliance on The Platformℒ​

Orbit's codebase continues to evolve with the web, adopting new ES language and web platform features as they are released. Custom utilities have been gradually deprecated and phased out of the codebase (e.g. isArray -> Array.isArray), new language features such as nullish coalescing and optional chaining have been adopted, and platform features such as crypto.randomUUID have been adopted (with a fallback implementation if unavailable).


Many thanks to the contributors who made v0.17 possible: