javascript - 如果我只有 PDF URL，如何将 PDF 作为附件发送

Question

我有一个离子应用程序，它根据用户的输入进行某些计算。计算后，结果通过 API(generatePDF) 调用转换为 PDF。另一个要求是通过电子邮件发送相同的 PDF。一个 API(sendMail) 也是为此而生的。enctype='multipart/form-data'在 sendMail API 的标头部分中设置。

我现在有了 PDF URL，我得到了作为 generatePDF API 的响应。使用此 URL 如何将 PDF 附加到我打算发送的邮件中？

有人可以帮忙吗？

标签： javascriptionic-frameworkemail-attachments

Answer 1

谢谢@MissakBoyajian 的帮助。这就是我所做的。

为 ionic native 安装文件传输和文件插件

this.platform.ready().then(() => {

      const fileTransfer: FileTransferObject = this.transfer.create();
      const pdfLocation = this.pdffile;//pdffile is the PDF URL which we got as the response from the generatePDF API

      fileTransfer.download(pdfLocation, this.storageDirectory + "filename.pdf").then((entry) => {
        const alertSuccess = this.alertCtrl.create({
          title: `Download Succeeded!`,
          subTitle: `PDF was successfully downloaded to: ${entry.toURL()}`,
          buttons: ['Ok']
        });

        alertSuccess.present();

        this.file.readAsDataURL(this.storageDirectory, 'filename.pdf')
        .then((datafile) =>{
          this.attachpdf(id,datafile);
        })
        .catch((err) =>{
          console.log("Error is that "+err);
        });

      }, (error) => {

        const alertFailure = this.alertCtrl.create({
          title: `Download Failed!`,
          subTitle: `PDF was not successfully downloaded. Error code: ${error.code}`,
          buttons: ['Ok']
        });
        alertFailure.present();
      });
    });

使用一个函数（我从搜索中获得）将 base64data 转换为 blob。

    public dataURItoBlob(dataURI) {
    // convert base64/URLEncoded data component to raw binary data held in a string
    var byteString;
    if (dataURI.split(',')[0].indexOf('base64') >= 0)
        byteString = atob(dataURI.split(',')[1]);
    else
        byteString = unescape(dataURI.split(',')[1]);
    // separate out the mime component
    var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];

    // write the bytes of the string to a typed array
    var ia = new Uint8Array(byteString.length);
    for (var i = 0; i < byteString.length; i++) {
        ia[i] = byteString.charCodeAt(i);
    }

    return new Blob([ia], {type:mimeString});
 }

然后，

    public attachpdf(emailid,filetoattach){
     let headers = new Headers();
    headers.append(...);
    headers.append('enctype','multipart/form-data');

    var blob = this.dataURItoBlob(filetoattach);

    var data ={... };

    var formData = new FormData();
    formData.append("data",JSON.stringify(data));
    formData.append("doc",blob);

    this.http.post('sendMail API',formData, {headers: headers})
    .map(res => res.json())
    .subscribe(results => { 
      ...
    },
    error=>{
      ..
    }
    )
  }

它终于奏效了。