Files
blockly/core/field_registry.ts
Rachel Fenichel 1d1a927628 chore: remove alias comments (#6816)
* chore: remove alias comments

* chore: format

* chore: remove extra newlines

* chore: fix bad replaces
2023-02-06 10:08:55 -08:00

89 lines
2.7 KiB
TypeScript

/**
* @license
* Copyright 2019 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* Fields can be created based on a JSON definition. This file
* contains methods for registering those JSON definitions, and building the
* fields based on JSON.
*
* @namespace Blockly.fieldRegistry
*/
import * as goog from '../closure/goog/goog.js';
goog.declareModuleId('Blockly.fieldRegistry');
import type {Field, FieldProto} from './field.js';
import * as registry from './registry.js';
interface RegistryOptions {
type: string;
[key: string]: unknown;
}
/**
* Registers a field type.
* fieldRegistry.fromJson uses this registry to
* find the appropriate field type.
*
* @param type The field type name as used in the JSON definition.
* @param fieldClass The field class containing a fromJson function that can
* construct an instance of the field.
* @throws {Error} if the type name is empty, the field is already registered,
* or the fieldClass is not an object containing a fromJson function.
*/
export function register(type: string, fieldClass: FieldProto) {
registry.register(registry.Type.FIELD, type, fieldClass);
}
/**
* Unregisters the field registered with the given type.
*
* @param type The field type name as used in the JSON definition.
*/
export function unregister(type: string) {
registry.unregister(registry.Type.FIELD, type);
}
/**
* Construct a Field from a JSON arg object.
* Finds the appropriate registered field by the type name as registered using
* fieldRegistry.register.
*
* @param options A JSON object with a type and options specific to the field
* type.
* @returns The new field instance or null if a field wasn't found with the
* given type name
* @internal
*/
export function fromJson<T>(options: RegistryOptions): Field<T>|null {
return TEST_ONLY.fromJsonInternal(options);
}
/**
* Private version of fromJson for stubbing in tests.
*
* @param options
*/
function fromJsonInternal<T>(options: RegistryOptions): Field<T>|null {
const fieldObject = registry.getObject(registry.Type.FIELD, options.type);
if (!fieldObject) {
console.warn(
'Blockly could not create a field of type ' + options['type'] +
'. The field is probably not being registered. This could be because' +
' the file is not loaded, the field does not register itself (Issue' +
' #1584), or the registration is not being reached.');
return null;
} else if (typeof (fieldObject as any).fromJson !== 'function') {
throw new TypeError('returned Field was not a IRegistrableField');
} else {
type fromJson = (options: {}) => Field<T>;
return (fieldObject as unknown as {fromJson: fromJson}).fromJson(options);
}
}
export const TEST_ONLY = {
fromJsonInternal,
};