在Firebase功能中从Firebase存储中填充PDFKit图像？

Populating a PDFKit Image from Firebase Storage while in a Firebase Function?

我一直在尝试从PDFKit中填充PDFDoc中的图像，但无法使其正常工作。使用以下功能时，Firebase控制台功能日志中会出现以下错误。该文件以" image / png"类型存储在Firebase Storage中。名称只是一个字符串。我尝试在名称后附加" .PNG"，但收到相同的错误。我包含了整个函数文件，因为也许有一种更可接受的方式来处理此问题？在使用Firebase功能时，如何从Firebase存储中将PDF插入PDFDoc？谢谢。

获取文档时出错：错误：图像格式未知。
在Function.PDFImage.open(/user_code/node_modules/pdfkit/js/image.js:43:15)
在PDFDocument.openImage(/user_code/node_modules/pdfkit/js/mixins/images.js:102:26)
在PDFDocument.image(/user_code/node_modules/pdfkit/js/mixins/images.js:30:24)
在/user_code/lib/index.js:71:48
在QuerySnapshot.forEach(/user_code/node_modules/firebase-admin/node_modules/@google-cloud/firestore/src/reference.js:1012:16)
在/user_code/lib/index.js:24:31
在process._tickDomainCallback(内部/进程/next_tick.js:135:7)

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import * as functions from 'firebase-functions';
import * as admin from 'firebase-admin';
import * as firebase from 'firebase/app';
import * as PDFDocument from 'pdfkit';

admin.initializeApp(functions.config().firebase);

export const genPdf = functions.https.onRequest((request, response) => {

const bucket = admin.storage().bucket("decteac2-3hcec.appspot.com");

const text = request.query.text;
const pdfdoc = new PDFDocument({ autoFirstPage: false });
pdfdoc.info['Title'] = text +".pdf";

let x = 5;
let y = 5;

pdfdoc.pipe(response);

const docRef = admin.firestore().collection("cxforms").doc(text);
docRef.get().then(function (doc) {
if (doc.exists) {
const pagesRef = admin.firestore().collection("pages").where("formKey","==", text).orderBy("pageno");
pagesRef.get().then(function (querySnapshot) {
let cnt = 1;
querySnapshot.forEach(function (page) {
pdfdoc.addPage({ margin: 0 });
x = 5;
y = 5;
pdfdoc.moveTo(x, y)
.lineTo(607, 5)
.lineTo(607, 787)
.lineTo(5, 787)
.lineTo(x, y)
.stroke();
for (let i = 0; i < page.data().tables.length; i++) {
const table = page.data().tables[i];
y = y + 8.5; // margin

var tableWidth = 5;
for (let p = 0; p < table.cols.length; p++) {
tableWidth = tableWidth + (table.cols[p] * .82);
}
var offset = (597 - tableWidth) / 2;
for (let j = 0; j < table.rows.length; j++) {
const row = table.rows[j];
x = 10 + offset;
for (let k = 0; k < row.cells.length; k++) {
const cell = row.cells[k];
const colwidth = table.cols[k];
var height = 22.2;
for (let l = 0; l < cell.cellels.length; l++) {
const cellEl = cell.cellels[l];

if (cellEl.type ==="Text") {
pdfdoc.text(cellEl.text, x + 1, y + 7);
} else if (cellEl.type =="Image") {
const filename = cellEl.storageid;
const file = bucket.file(filename);
const bucketFileStream = file.createWriteStream();
const buffer = new Buffer([1000000]);
bucketFileStream.write(buffer);
bucketFileStream.end();
pdfdoc.image(buffer, x, y);

}
}
if (height < 20) {
height = 20;
}
pdfdoc.moveTo(x, y)
.lineTo(x + (colwidth * .82), y)
.lineTo(x + (colwidth * .82), y + height)
.lineTo(x, y + height)
.lineTo(x, y)
.stroke();
x = x + (colwidth * .82);
}
y = y + height;
}
}
cnt++;
});
pdfdoc.end();
}).catch(function (error) {
console.log("Error getting documents:", error);
})

} else {
console.log("No such document!");
}
}).catch(function (error) {
console.log("Error gettting documents:", error);
});
});

这就是我如何解决这个问题的方法。关键项目是将响应编码设置为" base64"以调用Firestorage。另一个项目正在使用async和await，以便等待每个单元格元素图像填充pdfdoc，然后再继续下一个要呈现的单元格元素。

if(cellEl.type ==" Image"){等待toBase64(cellEl.url，x，y，pdfdoc);}

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