如何使用 Angular 的 2+ @angular/http 模块接收 blob 响应？

Question

我正在尝试从 angular 2 应用程序中提供 pdf 下载...

此代码有效：

    var reportPost = 'variable=lsdkjf';

    var xhr = new XMLHttpRequest();

    xhr.open("POST", "http://localhost/a2/pdf.php", true);
    xhr.responseType = 'blob';
    xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

    xhr.onreadystatechange = function() {//Call a function when the state changes.
        if(xhr.readyState == 4 && xhr.status == 200) {
            var blob = new Blob([this.response], {type: 'application/pdf'});
            saveAs(blob, "Report.pdf");
        }
    }

    xhr.send(reportPost);

但我更愿意使用 angular 2 的内置 Http 客户端。

一点研究：

angular 文档在发布时未写入： https://angular.io/docs/js/latest/api/http/ResponseTypes-enum.html
不确定这是否适用，但 rxjs responseType 参数似乎仅包含文本和 json： https://github.com/Reactive-Extensions/RxJS-DOM/blob/master/doc/operators/ajax.md

和一些测试代码：

    var headers = new Headers();
    headers.append('Content-Type', 'application/x-www-form-urlencoded');

    this.http.post('http://localhost/a2/pdf.php', reportPost,  {
        headers: headers
        })
        .retry(3)
        // .map( (res:any) => res.blob() ) // errors out
        .subscribe(
          (dataReceived:any) => {
            var blob = new Blob([dataReceived._body], {type: 'application/pdf'});
            saveAs(blob, "Report.pdf");
          },
          (err:any) => this.logError(err),
          () => console.log('Complete')
        );

ps。 saveAs 函数来自这里：https://github.com/eligrey/FileSaver.js

Answer 1

随着 Angular2 final 的发布，我们可以定义一个服务：

@Injectable()
export class AngularService {

    constructor(private http: Http) {}

    download(model: MyModel) { //get file from service
        this.http.post("http://localhost/a2/pdf.php", JSON.stringify(model), {
            method: RequestMethod.Post,
            responseType: ResponseContentType.Blob,
            headers: new Headers({'Content-Type', 'application/x-www-form-urlencoded'})
        }).subscribe(
            response => { // download file
                var blob = new Blob([response.blob()], {type: 'application/pdf'});
                var filename = 'file.pdf';
                saveAs(blob, filename);
            },
            error => {
                console.error(`Error: ${error.message}`);
            }
        );
    }
}

此服务将获取文件，然后将其提供给用户。

zip 文件示例：

Answer 2

使用 @4.3, @5 和 HttpClientModule，我最终做了：

this.http.post(`${environment.server}/my/download`,
                data, 
                {responseType: 'blob', observe: 'response'})
              .map( res => ({content: res.body, 
                             fileName: res.headers.get('content-filename')}));

Answer 3

看这里：

return this._http.get('/api/images/' + _id, {responseType: 'blob'}).map(blob => {
  var urlCreator = window.URL;
  return this._sanitizer.bypassSecurityTrustUrl(urlCreator.createObjectURL(blob));
})

如何使用 Angular 的 2+ @angular/http 模块接收 blob 响应？

How to receive blob responses using Angular's 2+ @angular/http module?

rxjs

angular