Class: ReadOnlyContextError

API / @xmachines/play-view / errors / ReadOnlyContextError

Defined in: packages/play-view/src/errors.ts:34

A write reached the context projection of the view store.

The /context subtree of a view mirrors the context of the machine, and it is a READ of that context. A write there would hold a value that the next snapshot of the machine throws away, so the store refuses it. Send the actor an event instead: the context changes in the machine, and the projection follows.

Example

import { ReadOnlyContextError } from "@xmachines/play-view/errors";

try {
  store.set("/context/user/name", "Alice");
} catch (error) {
  if (error instanceof ReadOnlyContextError) {
    actor.send({ type: "user.rename", name: "Alice" });
  }
}

Extends

PlayError

Constructors

Constructor

new ReadOnlyContextError(path, stateKey): ReadOnlyContextError;

Defined in: packages/play-view/src/errors.ts:42

Parameters

Parameter	Type	Description
`path`	`string`	The path of the refused write.
`stateKey`	`string`	The key of the context subtree, for the message.

Returns

ReadOnlyContextError

Overrides

PlayError.constructor

Properties

Property	Modifier	Type	Description	Inherited from	Defined in
`cause?`	`public`	`unknown`	-	`PlayError`.`cause`	-
`code`	`readonly`	`string`	A stable, machine-readable identifier of the error. An error code follows the naming convention `<PACKAGE>_<DESCRIPTION>`, and a Play package writes `PLAY_<PACKAGE>_<DESCRIPTION>`. A code stays the same across each patch release and each minor release of one major version. Never match on `.message`. Always match on `.code`, or on the subclass.	`PlayError`.`code`	packages/core/src/errors.ts:56
`message`	`public`	`string`	-	`PlayError`.`message`	-
`name`	`public`	`string`	-	`PlayError`.`name`	-
`path`	`readonly`	`string`	The JSON pointer of the write that the store refused, as the caller gave it.	-	packages/play-view/src/errors.ts:36
`scope`	`readonly`	`string`	The class or the module that threw this error, for example `"asDisposable"`.	`PlayError`.`scope`	packages/core/src/errors.ts:46
`stack?`	`public`	`string`	-	`PlayError`.`stack`	-
`stackTraceLimit`	`static`	`number`	The `Error.stackTraceLimit` property specifies the number of stack frames collected by a stack trace (whether generated by `new Error().stack` or `Error.captureStackTrace(obj)`). The default value is `10` but may be set to any valid JavaScript number. Changes will affect any stack trace captured after the value has been changed. If set to a non-number value, or set to a negative number, stack traces will not capture any frames.	`PlayError`.`stackTraceLimit`	-

Methods

captureStackTrace()

static captureStackTrace(targetObject, constructorOpt?): void;

Defined in: @types/node

Creates a .stack property on targetObject, which when accessed returns a string representing the location in the code at which Error.captureStackTrace() was called.

const myObject = {};
Error.captureStackTrace(myObject);
myObject.stack; // Similar to `new Error().stack`

The first line of the trace will be prefixed with ${myObject.name}: ${myObject.message}.

The optional constructorOpt argument accepts a function. If given, all frames above constructorOpt, including constructorOpt, will be omitted from the generated stack trace.

The constructorOpt argument is useful for hiding implementation details of error generation from the user. For instance:

function a() {
  b();
}

function b() {
  c();
}

function c() {
  // Create an error without stack trace to avoid calculating the stack trace twice.
  const { stackTraceLimit } = Error;
  Error.stackTraceLimit = 0;
  const error = new Error();
  Error.stackTraceLimit = stackTraceLimit;

  // Capture the stack trace above function b
  Error.captureStackTrace(error, b); // Neither function c, nor b is included in the stack trace
  throw error;
}

a();

Parameters

Parameter	Type
`targetObject`	`object`
`constructorOpt?`	`Function`

Returns

void

Inherited from

PlayError.captureStackTrace

isError()

static isError(error): error is Error;

Defined in: typescript

Indicates whether the argument provided is a built-in Error instance or not.

Parameters

Parameter	Type
`error`	`unknown`

Returns

error is Error

Inherited from

PlayError.isError

prepareStackTrace()

static prepareStackTrace(err, stackTraces): any;

Defined in: @types/node

Parameters

Parameter	Type
`err`	`Error`
`stackTraces`	`CallSite`[]

Returns

any

See

https://v8.dev/docs/stack-trace-api#customizing-stack-traces

Inherited from

PlayError.prepareStackTrace