从IONIC 3中的assets文件夹下载CSV文件

Question

我有一个demo-file.csv文件,它在assets/csv文件夹中,所以如何从手机上下载,

这是我的HTML和组件代码.

HTML代码

<button ion-button type="button" block (click)="downloadFile('assets/csv/demo-file.csv', 'demo-file.csv')">Download Demo File</button>

组件代码

 public downloadFile(link: any, fileName: any) {
      if (link) {
        let path = null;
        this.showWaitingLoading();
        if (this.platform.is('ios')) {
          path = this.file.documentsDirectory;
        } else {
          path = this.file.dataDirectory;
      }

      const transfer = this.transfer.create();

      transfer.download(link, path + fileName).then(entry => {
        this.dismissWaitingLoading();
        this.openFile(entry.toURL());
      }).catch(() => {
        this.dismissWaitingLoading();
        this.showToastMsg('error', "Something went wrong");
      });
     }
    }
/* ================= OPNE FILE FUNCTION ===========*/

public openFile(path: any) {
   this.fileOpener.open(path, 'application/*')
     .then(() => console.log('File is opened'))
     .catch((e: any) => console.log('Error openening file', e));
}

我无法下载文件,我的PATH中是否有任何遗漏？

Answer 1

尝试使用Http get读取它并将其写为Blob，示例代码如下，

export class csvPage {
  csvData: any[] = [];
  headerRow: any[] = [];

  constructor(public navCtrl: NavController, 
    public navParams: NavParams,
    private http: Http) {
      this.readCsvData();
  }

  private readCsvData() {
    this.http.get('assets/dummyData.csv')
      .subscribe(
      data => this.extractData(data),
      err => this.handleError(err)
      );
  }

  private extractData(res) {
    let csvData = res['_body'] || '';
    let parsedData = papa.parse(csvData).data;

    this.headerRow = parsedData[0];

    parsedData.splice(0, 1);
    this.csvData = parsedData;
  }

  downloadCSV() {
    let csv = papa.unparse({
      fields: this.headerRow,
      data: this.csvData
    });

    // Dummy implementation for Desktop download purpose
    var blob = new Blob([csv]);
    var a = window.document.createElement("a");
    a.href = window.URL.createObjectURL(blob);
    a.download = "newdata.csv";
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
  }

  private handleError(err) {
    console.log('something went wrong: ', err);
  }

}