@codesoul-co/hypha-core / modules/runtime/projection

• Package index: @codesoul-co/hypha-core
• Source: packages/core/src/modules/runtime/projection.ts
• Exports: 7

Using this module

Use the Projection module for executing runtime behavior at this boundary. It exports 2 classes, 1 function, 4 interfaces.

Import from the package entrypoint

import {
  InMemoryProjectionStore,
  ProjectionEngine,
  validateProjectionRecord,
} from '@codesoul-co/hypha-core';

import type {
  ProjectionDefinition,
  ProjectionEngineOptions,
  ProjectionRecord,
  ProjectionStore,
} from '@codesoul-co/hypha-core';

Usage patterns

• Use the 4 type/interface exports as static contracts in application code, adapters, or tests. Import them with import type; they do not exist at runtime.
• The module exposes 2 classes as constructable runtime implementations. Each symbol entry lists its constructor and public methods.
• The module exposes 1 function as direct operation entrypoints. Every overload, required/optional parameter, and return type is documented below.

Public exports

Symbol	Kind	Signature	Description
InMemoryProjectionStore	class	new InMemoryProjectionStore<TState = unknown>(): InMemoryProjectionStore<TState>	In Memory Projection Store class with 4 public constructor or member entries; its exact declarations are listed below.
ProjectionEngine	class	new ProjectionEngine(options: ProjectionEngineOptions): ProjectionEngine	Projection Engine class with 3 public constructor or member entries; its exact declarations are listed below.
validateProjectionRecord	function	validateProjectionRecord<TState>(record: ProjectionRecord<TState>): void	Validate Projection Record function with 1 public call signature; parameters and return types are listed below.
ProjectionDefinition	interface	interface ProjectionDefinition	Projection Definition interface with 5 public fields or methods.
ProjectionEngineOptions	interface	interface ProjectionEngineOptions	Projection Engine Options interface with 2 public fields or methods.
ProjectionRecord	interface	interface ProjectionRecord	Projection Record interface with 7 public fields or methods.
ProjectionStore	interface	interface ProjectionStore	Projection Store interface with 3 public fields or methods.

InMemoryProjectionStore

In Memory Projection Store class with 4 public constructor or member entries; its exact declarations are listed below.

• Kind: class
• Import: import { InMemoryProjectionStore } from '@codesoul-co/hypha-core';
• Source module: modules/runtime/projection

Declaration

export declare class InMemoryProjectionStore<TState = unknown> implements ProjectionStore<TState> {
    get(projectionId: string, key: string): Promise<ProjectionRecord<TState> | null>;
    put(record: ProjectionRecord<TState>, expectedRevision?: number): Promise<void>;
    delete(projectionId: string, key: string): Promise<void>;
}

Public members

Member	Kind	Signature	Description
constructor	constructor	<TState = unknown>(): InMemoryProjectionStore<TState>	Creates an instance of this class.
delete	method	delete(projectionId: string, key: string): Promise<void>	Public method; parameters and return type are shown in the signature.
get	method	get(projectionId: string, key: string): Promise<ProjectionRecord<TState> | null>	Public method; parameters and return type are shown in the signature.
put	method	put(record: ProjectionRecord<TState>, expectedRevision?: number): Promise<void>	Public method; parameters and return type are shown in the signature.

ProjectionEngine

Projection Engine class with 3 public constructor or member entries; its exact declarations are listed below.

• Kind: class
• Import: import { ProjectionEngine } from '@codesoul-co/hypha-core';
• Source module: modules/runtime/projection

Declaration

export declare class ProjectionEngine {
    constructor(options: ProjectionEngineOptions);
    update<TState>(definition: ProjectionDefinition<TState>, store: ProjectionStore<TState>, scope: EventStreamScope, key?: string): Promise<ProjectionRecord<TState>>;
    rebuild<TState>(definition: ProjectionDefinition<TState>, store: ProjectionStore<TState>, scope: EventStreamScope, key?: string): Promise<ProjectionRecord<TState>>;
}

Public members

Member	Kind	Signature	Description
constructor	constructor	(options: ProjectionEngineOptions): ProjectionEngine	Creates an instance of this class.
rebuild	method	rebuild<TState>(definition: ProjectionDefinition<TState>, store: ProjectionStore<TState>, scope: EventStreamScope, key?: string): Promise<ProjectionRecord<TState>>	Public method; parameters and return type are shown in the signature.
update	method	update<TState>(definition: ProjectionDefinition<TState>, store: ProjectionStore<TState>, scope: EventStreamScope, key?: string): Promise<ProjectionRecord<TState>>	Public method; parameters and return type are shown in the signature.

validateProjectionRecord

Validate Projection Record function with 1 public call signature; parameters and return types are listed below.

• Kind: function
• Import: import { validateProjectionRecord } from '@codesoul-co/hypha-core';
• Source module: modules/runtime/projection

Declaration

export declare function validateProjectionRecord<TState>(record: ProjectionRecord<TState>): void;

Call signature

validateProjectionRecord<TState>(record: ProjectionRecord<TState>): void

Parameters

Parameter	Type	Required	Description
record	ProjectionRecord<TState>	Yes	Required parameter; accepted values are defined by the type column.

Returns

• Type: void
• Description: Returns no value.

ProjectionDefinition

Projection Definition interface with 5 public fields or methods.

• Kind: interface
• Import: import type { ProjectionDefinition } from '@codesoul-co/hypha-core';
• Source module: modules/runtime/projection

Declaration

export interface ProjectionDefinition<TState> {
    id: string;
    version: string;
    initialState(): TState;
    applies(event: PersistedFrameworkEvent): boolean;
    reduce(state: TState, event: PersistedFrameworkEvent): TState;
}

Contract members

Member	Kind	Signature	Description
applies	method	applies(event: PersistedFrameworkEvent): boolean	Public method; parameters and return type are shown in the signature.
id	property	id: string	Public property; its type, readonly modifier and optionality are shown in the signature.
initialState	method	initialState(): TState	Public method; parameters and return type are shown in the signature.
reduce	method	reduce(state: TState, event: PersistedFrameworkEvent): TState	Public method; parameters and return type are shown in the signature.
version	property	version: string	Public property; its type, readonly modifier and optionality are shown in the signature.

ProjectionEngineOptions

Projection Engine Options interface with 2 public fields or methods.

• Kind: interface
• Import: import type { ProjectionEngineOptions } from '@codesoul-co/hypha-core';
• Source module: modules/runtime/projection

Declaration

export interface ProjectionEngineOptions {
    events: Pick<EventRuntime, 'read'>;
    now?: () => string;
}

Contract members

Member	Kind	Signature	Description
events	property	events: Pick<EventRuntime, "read">	Public property; its type, readonly modifier and optionality are shown in the signature.
now	method	now?(): string	Public method; parameters and return type are shown in the signature.

ProjectionRecord

Projection Record interface with 7 public fields or methods.

• Kind: interface
• Import: import type { ProjectionRecord } from '@codesoul-co/hypha-core';
• Source module: modules/runtime/projection

Declaration

export interface ProjectionRecord<TState = unknown> {
    projectionId: string;
    projectionVersion: string;
    key: string;
    state: TState;
    lastSequence: number;
    revision: number;
    updatedAt: string;
}

Contract members

Member	Kind	Signature	Description
key	property	key: string	Public property; its type, readonly modifier and optionality are shown in the signature.
lastSequence	property	lastSequence: number	Public property; its type, readonly modifier and optionality are shown in the signature.
projectionId	property	projectionId: string	Public property; its type, readonly modifier and optionality are shown in the signature.
projectionVersion	property	projectionVersion: string	Public property; its type, readonly modifier and optionality are shown in the signature.
revision	property	revision: number	Public property; its type, readonly modifier and optionality are shown in the signature.
state	property	state: TState	Public property; its type, readonly modifier and optionality are shown in the signature.
updatedAt	property	updatedAt: string	Public property; its type, readonly modifier and optionality are shown in the signature.

ProjectionStore

Projection Store interface with 3 public fields or methods.

• Kind: interface
• Import: import type { ProjectionStore } from '@codesoul-co/hypha-core';
• Source module: modules/runtime/projection

Declaration

export interface ProjectionStore<TState = unknown> {
    get(projectionId: string, key: string): Promise<ProjectionRecord<TState> | null>;
    put(record: ProjectionRecord<TState>, expectedRevision?: number): Promise<void>;
    delete?(projectionId: string, key: string): Promise<void>;
}

Contract members

Member	Kind	Signature	Description
delete	method	delete?(projectionId: string, key: string): Promise<void>	Public method; parameters and return type are shown in the signature.
get	method	get(projectionId: string, key: string): Promise<ProjectionRecord<TState> | null>	Public method; parameters and return type are shown in the signature.
put	method	put(record: ProjectionRecord<TState>, expectedRevision?: number): Promise<void>	Public method; parameters and return type are shown in the signature.