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| 1 | +// Copyright IBM Corp. 2013,2017. All Rights Reserved. |
| 2 | +// Node module: @loopback/metadata |
| 3 | +// This file is licensed under the MIT License. |
| 4 | +// License text available at https://opensource.org/licenses/MIT |
| 5 | + |
| 6 | +import {Reflector, NamespacedReflect} from './reflect'; |
| 7 | +import {MetadataMap} from './decorator-factory'; |
| 8 | + |
| 9 | +const TSReflector = new NamespacedReflect(); |
| 10 | + |
| 11 | +/** |
| 12 | + * Design time metadata for a method |
| 13 | + */ |
| 14 | +export interface DesignTimeMethodMetadata { |
| 15 | + type: Function; |
| 16 | + parameterTypes: Function[]; |
| 17 | + returnType: Function; |
| 18 | +} |
| 19 | + |
| 20 | +/** |
| 21 | + * Inspector for metadata applied by decorators |
| 22 | + */ |
| 23 | +export class MetadataInspector { |
| 24 | + /** |
| 25 | + * Get the metadata associated with the given key for a given class |
| 26 | + * @param key Metadata key |
| 27 | + * @param target Class that contains the metadata |
| 28 | + */ |
| 29 | + static getClassMetadata<T>(key: string, target: Function): T | undefined { |
| 30 | + return Reflector.getMetadata(key, target); |
| 31 | + } |
| 32 | + |
| 33 | + /** |
| 34 | + * Get the metadata associated with the given key for all methods of the |
| 35 | + * target class or prototype |
| 36 | + * @param key Metadata key |
| 37 | + * @param target Class for static methods or prototype for instance methods |
| 38 | + */ |
| 39 | + static getAllMethodMetadata<T>( |
| 40 | + key: string, |
| 41 | + target: Object, |
| 42 | + ): MetadataMap<T> | undefined { |
| 43 | + return Reflector.getMetadata(key, target); |
| 44 | + } |
| 45 | + |
| 46 | + /** |
| 47 | + * Get the metadata associated with the given key for a given method of the |
| 48 | + * target class or prototype |
| 49 | + * @param key Metadata key |
| 50 | + * @param target Class for static methods or prototype for instance methods |
| 51 | + * @param methodName Method name. If not present, default to '' to use |
| 52 | + * the constructor |
| 53 | + */ |
| 54 | + static getMethodMetadata<T>( |
| 55 | + key: string, |
| 56 | + target: Object, |
| 57 | + methodName?: string | symbol, |
| 58 | + ): T | undefined { |
| 59 | + methodName = methodName || ''; |
| 60 | + const meta: MetadataMap<T> = Reflector.getMetadata(key, target); |
| 61 | + return meta && meta[methodName]; |
| 62 | + } |
| 63 | + |
| 64 | + /** |
| 65 | + * Get the metadata associated with the given key for all properties of the |
| 66 | + * target class or prototype |
| 67 | + * @param key Metadata key |
| 68 | + * @param target Class for static methods or prototype for instance methods |
| 69 | + */ |
| 70 | + static getAllPropertyMetadata<T>( |
| 71 | + key: string, |
| 72 | + target: Object, |
| 73 | + ): MetadataMap<T> | undefined { |
| 74 | + return Reflector.getMetadata(key, target); |
| 75 | + } |
| 76 | + |
| 77 | + /** |
| 78 | + * Get the metadata associated with the given key for a given property of the |
| 79 | + * target class or prototype |
| 80 | + * @param key Metadata key |
| 81 | + * @param target Class for static properties or prototype for instance |
| 82 | + * properties |
| 83 | + * @param propertyName Property name |
| 84 | + */ |
| 85 | + static getPropertyMetadata<T>( |
| 86 | + key: string, |
| 87 | + target: Object, |
| 88 | + propertyName: string | symbol, |
| 89 | + ): T | undefined { |
| 90 | + const meta: MetadataMap<T> = Reflector.getMetadata(key, target); |
| 91 | + return meta && meta[propertyName]; |
| 92 | + } |
| 93 | + |
| 94 | + /** |
| 95 | + * Get the metadata associated with the given key for all parameters of a |
| 96 | + * given method |
| 97 | + * @param key Metadata key |
| 98 | + * @param target Class for static methods or prototype for instance methods |
| 99 | + * @param methodName Method name. If not present, default to '' to use |
| 100 | + * the constructor |
| 101 | + */ |
| 102 | + static getAllParameterMetadata<T>( |
| 103 | + key: string, |
| 104 | + target: Object, |
| 105 | + methodName?: string | symbol, |
| 106 | + ): T[] | undefined { |
| 107 | + methodName = methodName || ''; |
| 108 | + const meta: MetadataMap<T[]> = Reflector.getMetadata(key, target); |
| 109 | + return meta && meta[methodName]; |
| 110 | + } |
| 111 | + |
| 112 | + /** |
| 113 | + * Get the metadata associated with the given key for a parameter of a given |
| 114 | + * method by index |
| 115 | + * @param key Metadata key |
| 116 | + * @param target Class for static methods or prototype for instance methods |
| 117 | + * @param methodName Method name. If not present, default to '' to use |
| 118 | + * the constructor |
| 119 | + * @param index Index of the parameter, starting with 0 |
| 120 | + */ |
| 121 | + static getParameterMetadata<T>( |
| 122 | + key: string, |
| 123 | + target: Object, |
| 124 | + methodName: string | symbol, |
| 125 | + index: number, |
| 126 | + ): T | undefined { |
| 127 | + methodName = methodName || ''; |
| 128 | + const meta: MetadataMap<T[]> = Reflector.getMetadata(key, target); |
| 129 | + const params = meta && meta[methodName]; |
| 130 | + return params && params[index]; |
| 131 | + } |
| 132 | + |
| 133 | + /** |
| 134 | + * Get TypeScript design time type for the property |
| 135 | + * @param target Class or prototype |
| 136 | + * @param propertyName Property name |
| 137 | + */ |
| 138 | + static getDesignTypeForProperty( |
| 139 | + target: Object, |
| 140 | + propertyName: string | symbol, |
| 141 | + ): Function { |
| 142 | + return TSReflector.getMetadata('design:type', target, propertyName); |
| 143 | + } |
| 144 | + |
| 145 | + static getDesignTypeForMethod( |
| 146 | + target: Object, |
| 147 | + methodName: string | symbol, |
| 148 | + ): DesignTimeMethodMetadata { |
| 149 | + const type = TSReflector.getMetadata('design:type', target, methodName); |
| 150 | + const parameterTypes = TSReflector.getMetadata( |
| 151 | + 'design:paramtypes', |
| 152 | + target, |
| 153 | + methodName, |
| 154 | + ); |
| 155 | + const returnType = TSReflector.getMetadata( |
| 156 | + 'design:returntype', |
| 157 | + target, |
| 158 | + methodName, |
| 159 | + ); |
| 160 | + return { |
| 161 | + type, |
| 162 | + parameterTypes, |
| 163 | + returnType, |
| 164 | + }; |
| 165 | + } |
| 166 | +} |
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