Issues with Reflect.getMetadata functionality in Angular 2

When I utilized this code snippet 

(Reflect.getMetadata('annotations',AppComponent)[0].template);
in a Plunker, it functioned correctly http://plnkr.co/edit/f47uORghJXaq0FtD00Th?p=preview

However, when implementing it in my project, I encountered the following error: 

Property 'getMetadata' does not exist on type 'typeof Reflect'

Below are the configurations for my project:

package.json

{
  "name": "ng2-demo",
  .
  .
  . (Contents omitted for brevity)
}

Systemjs.code.js 


(function (global) {
    .
    .
    . (Contents omitted for brevity)
})(this);

tsconfig.json

{
  "compilerOptions": {
    .
    .
    . (Contents omitted for brevity)
}

Despite still using angular2 rc2, I am unsure of the source of this error. Any help is greatly appreciated, thank you.

https://i.sstatic.net/HnNv2.png

typescriptangular

Answer №1

To enhance your component, insert the following line at the beginning:

///<reference path="../node_modules/reflect-metadata/reflect-metadata.d.ts"/>"

This suggestion is geared towards users of VScode.

Give it a try and see if it makes a difference.

Answer №2

To enhance your JavaScript capabilities, consider incorporating the core-js library. This library provides polyfills for ECMAScript versions 5, 6, and 7. Make sure to also install its typings by including 

"core-js": "registry:dt/core-js#0.0.0+20160317120654"
in your typings.json file and executing the command typings install

Answer №3

My issue surfaced when I halted the build process midway, only to resume it later even while running the project with "$ ionic serve" on a separate Cmder tab. Interestingly enough, this resolved the problem.

Note: The build was executed using the command "$ ionic build android" under Ionic 2 CLI version 2.1.18

Answer №4

The issue at hand pertains to Typescript. To address the problem, in addition to installing/updating the 'reflect-metadata' package to fix the error during build time, it is recommended to include the library file es2015.reflect in the tsconfig.json:


    "compilerOptions": {
        ...
        lib: [
            ...,
            "es2015.reflect",
            ...
        ]
        ...
    }
to resolve the warning in the IDE (confirmed on VSCode).

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