Javascript 在Node.js中提供动态生成的PDF和远程图像
我正在尝试创建一个节点服务器,该服务器使用。PDF是根据POST请求(via)的参数生成的。其中一个参数指定一个图像URL,服务器下载该URL并将其注入PDF 现在,我有以下结构:Javascript 在Node.js中提供动态生成的PDF和远程图像,javascript,node.js,express,node-pdfkit,Javascript,Node.js,Express,Node Pdfkit,我正在尝试创建一个节点服务器,该服务器使用。PDF是根据POST请求(via)的参数生成的。其中一个参数指定一个图像URL,服务器下载该URL并将其注入PDF 现在,我有以下结构: // Get dependencies var express = require('express'), http = require('http'), fs = require('fs'), pdfDocument = require('pdfkit'); // Get express started. var
// Get dependencies
var express = require('express'),
http = require('http'),
fs = require('fs'),
pdfDocument = require('pdfkit');
// Get express started.
var app = express();
// Use JSON in POST body
app.use(express.json());
// Setup POST response
app.post('/post_pdf', function(req, res) {
// Get the PDF initialized
var doc = new pdfDocument();
// Set some headers
res.statusCode = 200;
res.setHeader('Content-type', 'application/pdf');
res.setHeader('Access-Control-Allow-Origin', '*');
// Header to force download
res.setHeader('Content-disposition', 'attachment; filename=Untitled.pdf');
// Pipe generated PDF into response
doc.pipe(res);
/**
* Generate PDF contents
*/
// Prepare write stream for image
var image = fs.createWriteStream('image.jpeg');
// Download image
http.get("http://dummyimage.com/640.jpeg", function(response) {
// Pipe response into image write stream
// (because PDFKit needs to read from a saved file)
response.pipe(image).on('close', function() {
// Read data back, make sure there are no errors
fs.readFile('image.jpeg', function(err, data) {
if (err) throw err;
/**
* Use `data` to get image info (width, height, etc.)
* ------------------
* Inject image
*/
// Close document and response
doc.end();
res.end();
return;
})
});
});
});
我有两个问题:
- 是否有一种不那么麻烦的方法来实现这一点,也许是使用更少的嵌套回调?我完全愿意添加另一个依赖项,让生活更轻松
- 现在,上面的代码不起作用。它返回PDF,但PDF已损坏(根据预览)。任何关于为什么会发生这种情况的提示都是非常受欢迎的
缓冲区
doc.image(myBuffer); // You don't have to use a path string
将文件直接导入响应时,如果文件已关闭,则手动调用
response.end()
将导致问题
doc.pipe(res); // Pipe document directly into the response
doc.end(); // When called, this ends the file and the response
// res.end(); <-- DON'T call res.end()
// The response was already closed by doc.end()
return;
您是如何处理客户端部分以允许用户下载生成的pdf的?我正在尝试动态生成,不想保存到文件系统,而只是为用户启动下载。谢谢。我相信将
内容配置
标题更改为内联;filename=“
会起作用。告诉浏览器显示PDF。如果我想将页面/url转换为PDF如何。比如说www.google.com。这仍然适用吗?@ShenLance据我所知,不,这个答案不适用于通过网页快照生成的PDF。您如何处理客户端的响应?
var express = require('express'),
request = require('request'),
pdfDocument = require('pdfkit');
// Start Express
var app = express();
// Use JSON in POST body
app.use(express.json());
// Setup POST response
app.post('/post_pdf', function(req, res) {
// Create PDF
var doc = new pdfDocument();
// Write headers
res.writeHead(200, {
'Content-Type': 'application/pdf',
'Access-Control-Allow-Origin': '*',
'Content-Disposition': 'attachment; filename=Untitled.pdf'
});
// Pipe generated PDF into response
doc.pipe(res);
// Process image
request({
url: 'http://dummyimage.com/640.jpeg',
encoding: null // Prevents Request from converting response to string
}, function(err, response, body) {
if (err) throw err;
// Inject image
doc.image(body); // `body` is a Buffer because we told Request
// to not make it a string
doc.end(); // Close document and, by extension, response
return;
});
});
const fetch = require('node-fetch');
const PDFDocument = require('pdfkit');
const doc = new PDFDocument({});
url = AnyImageUrl;
res = await fetch(url,{encoding: null });
imageBuffer = await res.buffer();
img = new Buffer(imageBuffer, 'base64');
doc.image(img,(doc.page.width - 525) /2, doc.y, {align: 'center', width: 125});