Saving a Frontend Page as a PDF File

Since API version 14, the Web component supports the createPdf method for saving frontend pages as PDF files.

After an instance is generated using createPdf, obtain the binary stream using the pdfArrayBuffer method, and save it as a PDF file using the fileIo method. In this way, users can save frontend page content such as reports and invoices as PDF files for sharing.

Description

You can adjust the PDF page size and frontend page zoom ratio through pdfconfiguration. You are advised to use the frontend page adaptation policy and optimize the PDF layout through CSS media query (@media print).

Required Permissions

To obtain network documents, you need to configure the network access permission in the module.json5 file. For details, see Declaring Permissions in the Configuration File.

"requestPermissions": [
  {
    "name": "ohos.permission.INTERNET"
  }
],

Saving a PDF File Using a Callback

Call the createPdf API through a callback, obtain the PDF binary stream through the pdfArrayBuffer API based on the obtained result, and use the fileIo method to save it as a PDF file.

import { fileIo as fs } from '@kit.CoreFileKit';
import { webview } from '@kit.ArkWeb';
import { BusinessError } from '@kit.BasicServicesKit';
import { common } from '@kit.AbilityKit';

@Entry
@Component
struct Index {
  controller: webview.WebviewController = new webview.WebviewController();
  pdfConfig: webview.PdfConfiguration = {
    width: 8.27,
    height: 11.69,
    marginTop: 0,
    marginBottom: 0,
    marginRight: 0,
    marginLeft: 0,
    shouldPrintBackground: true
  };

  build() {
    Column() {
      Button('SavePDF')
        .onClick(() => {
          // Ensure that the page rendering is complete before triggering PDF file generation. You can use the onPageEnd event for listening.
          this.controller.createPdf(
            this.pdfConfig,
            (error, result: webview.PdfData) => {
              try {
                // Use the pdfArrayBuffer API to obtain the PDF binary stream and the fileIo API to save it as a PDF file.
                let context = this.getUIContext().getHostContext() as common.UIAbilityContext;
                let filePath = context.filesDir + '/test.pdf';
                let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
                fs.write(file.fd, result.pdfArrayBuffer().buffer).then((writeLen: number) => {
                  console.info('createPDF write data to file succeed and size is:' + writeLen);
                }).catch((err: BusinessError) => {
                  console.error('createPDF write data to file failed with error message: ' + err.message +
                      ', error code: ' + err.code);
                }).finally(() => {
                  // Close the file.
                  fs.closeSync(file);
                });
              } catch (resError) {
                console.error(
                  `ErrorCode: ${(error as BusinessError).code},  Message: ${(error as BusinessError).message}`);
              }
            });
        })
      Web({ src: 'www.example.com', controller: this.controller })
    }
  }
}

Saving a PDF File Using a Promise

Call the createPdf API through a promise, obtain the PDF binary stream through the pdfArrayBuffer API based on the obtained result, and use the fileIo method to save it as a PDF file.

import { fileIo as fs } from '@kit.CoreFileKit';
import { webview } from '@kit.ArkWeb';
import { BusinessError } from '@kit.BasicServicesKit';
import { common } from '@kit.AbilityKit';

@Entry
@Component
struct Index {
  controller: webview.WebviewController = new webview.WebviewController();
  pdfConfig: webview.PdfConfiguration = {
    width: 8.27,
    height: 11.69,
    marginTop: 0,
    marginBottom: 0,
    marginRight: 0,
    marginLeft: 0,
    shouldPrintBackground: true
  };

  build() {
    Column() {
      Button('SavePDF')
        .onClick(() => {
          // Ensure that the page rendering is complete before triggering PDF file generation. You can use the onPageEnd event for listening.
          this.controller.createPdf(this.pdfConfig)
            .then((result: webview.PdfData) => {
              try {
                // Use the pdfArrayBuffer API to obtain the PDF binary stream and the fileIo API to save it as a PDF file.
                let context = this.getUIContext().getHostContext() as common.UIAbilityContext;
                let filePath = context.filesDir + '/test.pdf';
                let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
                fs.write(file.fd, result.pdfArrayBuffer().buffer).then((writeLen: number) => {
                  console.info('createPDF write data to file succeed and size is:' + writeLen);
                }).catch((err: BusinessError) => {
                  console.error('createPDF write data to file failed with error message: ' + err.message +
                      ', error code: ' + err.code);
                }).finally(() => {
                  // Close the file.
                  fs.closeSync(file);
                });
              } catch (resError) {
                console.error(
                  `ErrorCode: ${(resError as BusinessError).code},  Message: ${(resError as BusinessError).message}`);
              }
            })
        })
      Web({ src: 'www.example.com', controller: this.controller })
    }
  }
}