@loopback/metadata
Version:
Utilities to help developers implement TypeScript decorators, define/merge metadata, and inspect metadata
186 lines • 8.74 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.MetadataInspector = void 0;
const tslib_1 = require("tslib");
// Copyright IBM Corp. and LoopBack contributors 2017,2019. All Rights Reserved.
// Node module: @loopback/metadata
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT
const debug_1 = tslib_1.__importDefault(require("debug"));
const decorator_factory_1 = require("./decorator-factory");
const reflect_1 = require("./reflect");
const debug = (0, debug_1.default)('loopback:metadata:inspector');
/**
* TypeScript reflector without a namespace. The TypeScript compiler can be
* configured to add design time metadata.
*
* See https://www.typescriptlang.org/docs/handbook/decorators.html
*/
const TSReflector = new reflect_1.NamespacedReflect();
/**
* Inspector for metadata applied by decorators
*/
class MetadataInspector {
/**
* Get the metadata associated with the given key for a given class
* @param key - Metadata key
* @param target - Class that contains the metadata
* @param options - Options for inspection
*/
static getClassMetadata(key, target, options) {
return (options === null || options === void 0 ? void 0 : options.ownMetadataOnly)
? reflect_1.Reflector.getOwnMetadata(key.toString(), target)
: reflect_1.Reflector.getMetadata(key.toString(), target);
}
/**
* Define metadata for the given target
* @param key - Metadata key
* @param value - Metadata value
* @param target - Target for the metadata
* @param member - Optional property or method name
*/
static defineMetadata(key, value, target, member) {
reflect_1.Reflector.defineMetadata(key.toString(), value, target, member);
}
/**
* Get the metadata associated with the given key for all methods of the
* target class or prototype
* @param key - Metadata key
* @param target - Class for static methods or prototype for instance methods
* @param options - Options for inspection
*/
static getAllMethodMetadata(key, target, options) {
return (options === null || options === void 0 ? void 0 : options.ownMetadataOnly)
? reflect_1.Reflector.getOwnMetadata(key.toString(), target)
: reflect_1.Reflector.getMetadata(key.toString(), target);
}
/**
* Get the metadata associated with the given key for a given method of the
* target class or prototype
* @param key - Metadata key
* @param target - Class for static methods or prototype for instance methods
* @param methodName - Method name. If not present, default to '' to use
* the constructor
* @param options - Options for inspection
*/
static getMethodMetadata(key, target, methodName, options) {
methodName = methodName !== null && methodName !== void 0 ? methodName : '';
const meta = (options === null || options === void 0 ? void 0 : options.ownMetadataOnly)
? reflect_1.Reflector.getOwnMetadata(key.toString(), target)
: reflect_1.Reflector.getMetadata(key.toString(), target);
return meta === null || meta === void 0 ? void 0 : meta[methodName];
}
/**
* Get the metadata associated with the given key for all properties of the
* target class or prototype
* @param key - Metadata key
* @param target - Class for static methods or prototype for instance methods
* @param options - Options for inspection
*/
static getAllPropertyMetadata(key, target, options) {
return (options === null || options === void 0 ? void 0 : options.ownMetadataOnly)
? reflect_1.Reflector.getOwnMetadata(key.toString(), target)
: reflect_1.Reflector.getMetadata(key.toString(), target);
}
/**
* Get the metadata associated with the given key for a given property of the
* target class or prototype
* @param key - Metadata key
* @param target - Class for static properties or prototype for instance
* properties
* @param propertyName - Property name
* @param options - Options for inspection
*/
static getPropertyMetadata(key, target, propertyName, options) {
const meta = (options === null || options === void 0 ? void 0 : options.ownMetadataOnly)
? reflect_1.Reflector.getOwnMetadata(key.toString(), target)
: reflect_1.Reflector.getMetadata(key.toString(), target);
return meta === null || meta === void 0 ? void 0 : meta[propertyName];
}
/**
* Get the metadata associated with the given key for all parameters of a
* given method
* @param key - Metadata key
* @param target - Class for static methods or prototype for instance methods
* @param methodName - Method name. If not present, default to '' to use
* the constructor
* @param options - Options for inspection
*/
static getAllParameterMetadata(key, target, methodName, options) {
methodName = methodName !== null && methodName !== void 0 ? methodName : '';
const meta = (options === null || options === void 0 ? void 0 : options.ownMetadataOnly)
? reflect_1.Reflector.getOwnMetadata(key.toString(), target)
: reflect_1.Reflector.getMetadata(key.toString(), target);
return meta === null || meta === void 0 ? void 0 : meta[methodName];
}
/**
* Get the metadata associated with the given key for a parameter of a given
* method by index
* @param key - Metadata key
* @param target - Class for static methods or prototype for instance methods
* @param methodName - Method name. If not present, default to '' to use
* the constructor
* @param index - Index of the parameter, starting with 0
* @param options - Options for inspection
*/
static getParameterMetadata(key, target, methodName, index, options) {
methodName = methodName || '';
const meta = (options === null || options === void 0 ? void 0 : options.ownMetadataOnly)
? reflect_1.Reflector.getOwnMetadata(key.toString(), target)
: reflect_1.Reflector.getMetadata(key.toString(), target);
const params = meta === null || meta === void 0 ? void 0 : meta[methodName];
return params === null || params === void 0 ? void 0 : params[index];
}
/**
* Get TypeScript design time type for a property
* @param target - Class or prototype
* @param propertyName - Property name
* @returns Design time metadata. The return value is `undefined` when:
* - The property has type `undefined`, `null`
* - The TypeScript project has not enabled the compiler option `emitDecoratorMetadata`.
* - The code is written in vanilla JavaScript.
*/
static getDesignTypeForProperty(target, propertyName) {
return TSReflector.getMetadata('design:type', target, propertyName);
}
/**
* Get TypeScript design time type for a method.
* @param target - Class or prototype
* @param methodName - Method name
* @returns Design time metadata. The return value is `undefined`
* in projects that do not enable `emitDecoratorMetadata`
* in TypeScript compiler options or are written in vanilla JavaScript.
*/
static getDesignTypeForMethod(target, methodName) {
const type = TSReflector.getMetadata('design:type', target, methodName);
const parameterTypes = TSReflector.getMetadata('design:paramtypes', target, methodName);
const returnType = TSReflector.getMetadata('design:returntype', target, methodName);
if (type === undefined &&
parameterTypes === undefined &&
returnType === undefined) {
/* istanbul ignore next */
if (debug.enabled) {
const targetName = decorator_factory_1.DecoratorFactory.getTargetName(target, methodName);
debug('No design-time type metadata found while inspecting %s. ' +
'Did you forget to enable TypeScript compiler option `emitDecoratorMetadata`?', targetName);
}
return undefined;
}
return {
type,
parameterTypes,
returnType,
};
}
}
exports.MetadataInspector = MetadataInspector;
/**
* Expose Reflector, which is a wrapper of `Reflect` and it uses `loopback`
* as the namespace prefix for all metadata keys
*/
MetadataInspector.Reflector = reflect_1.Reflector;
/**
* Expose the reflector for TypeScript design-time metadata
*/
MetadataInspector.DesignTimeReflector = TSReflector;
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