Question

我试图生成PDF文件，最终我将在HTTP调用中将其作为base64编码的字符串发送，但是现在我只想保存到文件中以便验证内容。

使用下面的代码，我得到一个名为consentTest.pdf的pdf文件，但是当我用pdf查看器打开它时，文件中没有任何内容。

当PDF生成后立即取消注释行doc.pipe(fs.createWriteStream('consent1.pdf'))时，我知道PDF是正确的b / c生成方式，当我在PDF查看器中打开它时，它将保存预期的内容。

'use strict'

const fs = require('fs')
const path = require('path')
const PDFDocument = require('pdfkit')

/**
 * Creates a pdf consent form to be sent as a base64encoded string
 */
function createPdfConsent() {
  let doc = new PDFDocument()
  writeContent(doc)
  // doc.pipe(fs.createWriteStream('consent1.pdf')) <-- THIS SUCCESSFULLY SAVES THE FILE WITH THE EXPECTED CONTENTS
  let file
  // Add every chunk to file
  doc.on('data', chunk => {
    if (file === undefined) {
      file = chunk
    } else {
      file += chunk
    }
  })

  // On complete, print the base64 encoded string, but also save to a file so we can verify it's contents
  doc.on('end', () => {
    const encodedFile = new Buffer(file)
    console.log('encodedFile = ', encodedFile.toString('base64'))

    // Testing printing the file back out from base64 encoding
    fs.writeFile('consentTest.pdf', encodedFile, err => {
      console.log('err = ', err)
    })
  })

  doc.end()
}

/************ Private *************

/**
 * Writes the consent content to the pdf
 * @param  {Object} doc The pdf document that we want to write to
 * @private
 */
function writeContent(doc) {
  doc.fontSize(16).text('This is the consent form', 50, 350)
}

module.exports = {
  createPdfConsent
}

Answer 1

似乎我不正确地处理/使用了块。

替换：

 ...
 let file
  // Add every chunk to file
  doc.on('data', chunk => {
    if (file === undefined) {
      file = chunk
    } else {
      file += chunk
    }
  })

  // On complete, print the base64 encoded string, but also save to a file so we can verify it's contents
  doc.on('end', () => {
    const encodedFile = new Buffer(file)
  ...

具有：

...
 let file = []
  // Add every chunk to file
  doc.on('data', chunk => {
    file.push(chunk)
  })

  doc.on('end', () => {
    const encodedFile = Buffer.concat(file)
  ...

是神奇的股票

生成一个PDF文件，然后将该文件保存在本地以验证它是否包含我期望的数据

1 个答案: