AWS SDK for JavaScript with Angular で Upload to S3.

欠員が出たということで、穴埋めさせていただきます。

# 概要
本記事は、**Angular**で**AWS SDK for JavaScript**を利用して、**S3**にファイルをアップロードするという内容です。
Angular メインですので、AWSサービスの使い方や設定については割愛いたします。ご了承ください。

# 環境
```
$ uname -a
Linux ip-10-4-0-188 4.9.62-21.56.amzn1.x86_64 #1 SMP Thu Nov 16 05:37:08 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
```

```
$ ng -v

    _                      _                 ____ _     ___
   / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
  / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
 / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
/_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
               |___/

Angular CLI: 1.5.5
Node: 8.9.1
OS: linux x64
Angular: 5.0.0
... animations, common, compiler, compiler-cli, core, forms
... http, language-service, platform-browser
... platform-browser-dynamic, router

@angular/cli: 1.5.5
@angular-devkit/build-optimizer: 0.0.35
@angular-devkit/core: 0.0.22
@angular-devkit/schematics: 0.0.41
@ngtools/json-schema: 1.1.0
@ngtools/webpack: 1.8.5
@schematics/angular: 0.1.10
@schematics/schematics: 0.0.10
typescript: 2.4.2
webpack: 3.8.1
```

```json:package.json
{
  "name": "qiita",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^5.0.0",
    "@angular/common": "^5.0.0",
    "@angular/compiler": "^5.0.0",
    "@angular/core": "^5.0.0",
    "@angular/forms": "^5.0.0",
    "@angular/http": "^5.0.0",
    "@angular/platform-browser": "^5.0.0",
    "@angular/platform-browser-dynamic": "^5.0.0",
    "@angular/router": "^5.0.0",
    "core-js": "^2.4.1",
    "rxjs": "^5.5.2",
    "zone.js": "^0.8.14"
  },
  "devDependencies": {
    "@angular/cli": "1.5.5",
    "@angular/compiler-cli": "^5.0.0",
    "@angular/language-service": "^5.0.0",
    "@types/jasmine": "~2.5.53",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "^4.0.1",
    "jasmine-core": "~2.6.2",
    "jasmine-spec-reporter": "~4.1.0",
    "karma": "~1.7.0",
    "karma-chrome-launcher": "~2.1.1",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~3.2.0",
    "tslint": "~5.7.0",
    "typescript": "~2.4.2"
  }
}
```

# 手順
## 1) **AWS SDK for JavaScript**をインストール

```
$ npm i --save-prod aws-sdk
```

## 2) ``src/app/tsconfig.app.json`` を編集

```diff:tsconfig.app.json
{
  "extends": "../tsconfig.json",
  "compilerOptions": {
    "outDir": "../out-tsc/app",
    "baseUrl": "./",
    "module": "es2015",
-    "types": []
+    "types": ["node"]
  },
  "exclude": [
    "test.ts",
    "**/*.spec.ts"
  ]
}
```
参照: [Usage_with_TypeScript](https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/#Usage_with_TypeScript)

## 3) S3アップロード用コンポネントを作成
```
$ ng g component s3-upload
  create src/app/s3-upload/s3-upload.component.css (0 bytes)
  create src/app/s3-upload/s3-upload.component.html (28 bytes)
  create src/app/s3-upload/s3-upload.component.spec.ts (643 bytes)
  create src/app/s3-upload/s3-upload.component.ts (280 bytes)
  update src/app/app.module.ts (408 bytes)
```

## 4) 各種ファイルを編集
### src/app/app.component.html
```diff
+ <app-s3-upload></app-s3-upload>
```

### src/app/app.module.ts
```ts
import { BrowserModule } from '@angular/platform-browser';
import { HttpClientModule } from '@angular/common/http';
import { NgModule } from '@angular/core';


import { AppComponent } from './app.component';
import { S3UploadComponent } from './s3-upload/s3-upload.component';
import { S3Service } from './s3-upload/s3.service';

@NgModule({
  declarations: [
    AppComponent,
    S3UploadComponent,
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
  ],
  providers: [
    S3Service,
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }
```

### src/app/s3-upload/s3-upload.html
```html
<div class="form">
  <div class="form-group">
    <label class="col-xs-2">select file</label>
    <div class="col-xs-10">
      <input type="file" (change)="upload($event)">
    </div>
  </div>
</div>
<div class="debug_print">
  <p>httpUploadProgress {{ httpUploadProgress | json }}</p>
</div>
```

### src/app/s3-upload/s3-upload.component.ts
```ts
import { Component, OnInit } from '@angular/core';
import { S3Service } from './s3.service';
import * as AWS from 'aws-sdk';

@Component({
  selector: 'app-s3-upload',
  templateUrl: './s3-upload.component.html',
  styleUrls: ['./s3-upload.component.css']
})
export class S3UploadComponent implements OnInit
{
  public httpUploadProgress: {[name: string]: any} = {
    ratio : 0,
    style : {
      width: '0',
    }
  };


  /**
   * @desc constructor
   */
  constructor(private s3Service: S3Service)
  {
    this.s3Service.initialize()
      .subscribe((res: boolean) => {
        if (! res) {
          console.log('S3 cognito init error');
        }
      })
  }


  /**
   * @desc Angular LifeCycle
   */
  ngOnInit()
  {
    this.s3Service.progress
      .subscribe((res: AWS.S3.ManagedUpload.Progress) => {
        this.httpUploadProgress.ratio = res.loaded * 100 / res.total;
        this.httpUploadProgress.style.width = this.httpUploadProgress.ratio + '%';
      });
  }


  /**
   * @desc file upload
   */
  public upload(event: Event): void
  {
    this.httpUploadProgress.ratio = 0;
    this.httpUploadProgress.style.width = '0';
    this.s3Service.onManagedUpload((<HTMLInputElement>event.target).files[0]);
  }
}
```

### src/app/s3-upload/s3.service.ts
```ts
import { Injectable, EventEmitter } from '@angular/core';
import { HttpClient, HttpErrorResponse } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/of';
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/map';
import * as AWS from 'aws-sdk';
import { AWS_ENV } from '../../environments/environment';

@Injectable()
export class S3Service
{
  private s3: AWS.S3;
  public progress: EventEmitter<AWS.S3.ManagedUpload.Progress> = new EventEmitter<AWS.S3.ManagedUpload.Progress>();


  constructor(private http: HttpClient) { }


  /**
   * @desc set CognitoIdentityId
   * 
   * @return string IdentityId: ex) ap-northeast-1:01234567-9abc-df01-2345-6789abcd
   */
  public initialize(): Observable<boolean>
  {
    return this.http.get('/assets/cognito.php')
      .map((res: any) => {
        // resに対する例外処理を追加する
        // ...

        // Amazon Cognito 認証情報プロバイダーを初期化します
        AWS.config.region = AWS_ENV.region;
        AWS.config.credentials = new AWS.CognitoIdentityCredentials({
          IdentityId: res.results[0].IdentityId,
        });
        this.s3 = new AWS.S3({
          apiVersion: AWS_ENV.s3.apiVersion,
          params: {Bucket: AWS_ENV.s3.Bucket},
        });
        return true;
      })

      .catch((err: HttpErrorResponse) => {
        console.error(err);
        return Observable.of(false);
      });
  }

  /**
   * @desc AWS.S3
   */
  public onManagedUpload(file: File): Promise<AWS.S3.ManagedUpload.SendData>
  {
    let params: AWS.S3.Types.PutObjectRequest = {
      Bucket: AWS_ENV.s3.Bucket,
      Key: file.name,
      Body: file,
    };
    let options: AWS.S3.ManagedUpload.ManagedUploadOptions = {
      params: params,
      partSize: 64*1024*1024,
    };
    let handler: AWS.S3.ManagedUpload = new AWS.S3.ManagedUpload(options);
    handler.on('httpUploadProgress', this._httpUploadProgress.bind(this));
    handler.send(this._send.bind(this));
    return handler.promise();
  }

  /**
   * @desc progress
   */
  private _httpUploadProgress(progress: AWS.S3.ManagedUpload.Progress): void
  {
    this.progress.emit(progress);
  }

  /**
   * @desc send
   */
  private _send(err: AWS.AWSError, data: AWS.S3.ManagedUpload.SendData): void
  {
    console.log('send()', err, data);
  }
}
```

### src/environments/environment.ts
```ts
// The file contents for the current environment will overwrite these during build.
// The build system defaults to the dev environment which uses `environment.ts`, but if you do
// `ng build --env=prod` then `environment.prod.ts` will be used instead.
// The list of which env maps to which file can be found in `.angular-cli.json`.

export const environment = {
  production: false
};

export const AWS_ENV = {
  region: 'YOUR_REGION',
  s3: {
    apiVersion: 'YOUR_VERSION',
    Bucket: 'YOUR_BACKET',
  },
};
```

## 5) ビルド＆実行＆確認
![test.png](https://qiita-image-store.s3.amazonaws.com/0/31085/97b17078-a041-3b0f-3544-8f04dab7c02c.png)


```
$ aws s3 ls s3://YOUR_BACKET/
2017-12-10 08:13:54   10485760 10MB.bin
```


# 解説

AWS SDKを使ってファイルをアップロードするには、**PutObject()**を使うのが手っ取り早いですが
JSからファイルをアップロードするときには、UI/UXの観点からプログレスを表示してあげるのがよいので
それに対応したメソッドである、**[ManagedUpload()](http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3/ManagedUpload.html)**を利用しました。

5.0.0 では、zoneを意識することなく、プログレスがきちんとレンダリングされましたので
プログレスバーの実装は容易に行なえます。


以上、穴埋め記事でした。

7日目は、@segawm さんです。