ByteScout Cloud API Server – PDF To Image API – JavaScript – Convert PDF To PNG From Uploaded File (Node.js) – Async API

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ByteScout Cloud API Server – PDF To Image API – JavaScript – Convert PDF To PNG From Uploaded File (Node.js) – Async API

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ByteScout-Cloud-API-Server-JavaScript-Convert-PDF-To-PNG-From-Uploaded-File-(Node-js)-Async-API.pdf

How to convert PDF to PNG from uploaded file (node for PDF to image API in JavaScript and ByteScout Cloud API Server

Learn to write code convert PDF to PNG from uploaded file (node for PDF to image API in JavaScript: Simple How To Tutorial

If you want a quick and easy way to add a required functionality into your application then check this sample source code documentation. ByteScout Cloud API Server was designed to assist PDF to image API in JavaScript. ByteScout Cloud API Server is the ready to deploy Web API Server that can be deployed in less than thirty minutes into your own in-house Windows server (no Internet connnection is required to process data!) or into private cloud server. Can store data on in-house local server based storage or in Amazon AWS S3 bucket. Processing data solely on the server using built-in ByteScout powered engine, no cloud services are used to process your data!.

This simple and easy to understand sample source code in JavaScript for ByteScout Cloud API Server contains different functions and options you should do calling the API to implement PDF to image API. This sample code in JavaScript is all you need. Just copy-paste it to the code editor, then add a reference to ByteScout Cloud API Server and you are ready to try it! This basic programming language sample code for JavaScript will do the whole work for you in implementing PDF to image API in your app.

ByteScout Cloud API Server – free trial version is available on our website. Also, there are other code samples to help you with your JavaScript application included into trial version.

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app.js

      /*jshint esversion: 6 */

// Please NOTE: In this sample we're assuming Cloud Api Server is hosted at "https://localhost". 
// If it's not then please replace this with with your hosting url.

var https = require("https");
var path = require("path");
var fs = require("fs");

// `request` module is required for file upload.
// Use "npm install request" command to install.
var request = require("request");

// Source PDF file
const SourceFile = "./sample.pdf";
// Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'.
const Pages = "";
// PDF document password. Leave empty for unprotected documents.
const Password = "";


// 1. RETRIEVE PRESIGNED URL TO UPLOAD FILE.
getPresignedUrl(SourceFile)
    .then(([uploadUrl, uploadedFileUrl]) => {
        // 2. UPLOAD THE FILE TO CLOUD.
        uploadFile(SourceFile, uploadUrl)
            .then(() => {
                // 3. CONVERT UPLOADED PDF FILE TO PNG
                convertPdfToPng(uploadedFileUrl, Password, Pages);
            })
            .catch(e => {
                console.log(e);
            });
    })
    .catch(e => {
        console.log(e);
    });


function getPresignedUrl(localFile) {
    return new Promise(resolve => {
        // Prepare request to `Get Presigned URL` API endpoint
        let queryPath = `/file/upload/get-presigned-url?contenttype=application/octet-stream&name=${path.basename(SourceFile)}`;
        let reqOptions = {
            host: "localhost",
            path: encodeURI(queryPath)
        };
        // Send request
        https.get(reqOptions, (response) => {
            response.on("data", (d) => {
                let data = JSON.parse(d);
                if (data.error == false) {
                    // Return presigned url we received
                    resolve([data.presignedUrl, data.url]);
                }
                else {
                    // Service reported error
                    console.log("getPresignedUrl(): " + data.message);
                }
            });
        })
            .on("error", (e) => {
                // Request error
                console.log("getPresignedUrl(): " + e);
            });
    });
}

function uploadFile(localFile, uploadUrl) {
    return new Promise(resolve => {
        fs.readFile(SourceFile, (err, data) => {
            request({
                method: "PUT",
                url: uploadUrl,
                body: data,
                headers: {
                    "Content-Type": "application/octet-stream"
                }
            }, (err, res, body) => {
                if (!err) {
                    resolve();
                }
                else {
                    console.log("uploadFile() request error: " + e);
                }
            });
        });
    });
}

function convertPdfToPng(uploadedFileUrl, password, pages) {
    // Prepare URL for `PDF To PNG` API call
    var queryPath = `/pdf/convert/to/png?password=${password}&pages=${pages}&url=${uploadedFileUrl}&async=True`;
    let reqOptions = {
        host: "localhost",
        path: encodeURI(queryPath),
        method: "GET" 
    };
    // Send request
    https.get(reqOptions, (response) => {
        response.on("data", (d) => {
            response.setEncoding("utf8");

            // Parse JSON response
            let data = JSON.parse(d);

            if (data.error == false) {
                console.log(`Job #${data.jobId} has been created!`);
                checkIfJobIsCompleted(data.jobId, data.url);
            }
            else {
                // Service reported error
                console.log("convertPdfToPng(): " + data.message);
            }
        });
    })
        .on("error", (e) => {
            // Request error
            console.log("convertPdfToPng(): " + e);
        });
}

function checkIfJobIsCompleted(jobId, resultFileUrlJson) {

    let queryPath = `/job/check?jobid=${jobId}`;
    let reqOptions = {
        host: "localhost",
        path: encodeURI(queryPath),
        method: "GET" 
    };

    https.get(reqOptions, (response) => {
        response.on("data", (d) => {
            response.setEncoding("utf8");

            // Parse JSON response
            let data = JSON.parse(d);
            console.log(`Checking Job #${jobId}, Status: ${data.status}, Time: ${new Date().toLocaleString()}`);

            if (data.status == "working") {
                // Check again after 3 seconds
                setTimeout(function(){checkIfJobIsCompleted(jobId, resultFileUrlJson)} , 3000);
            }
            else if (data.status == "success") {

                request({ method: 'GET', uri: resultFileUrlJson, gzip: true },
                    function (error, response, body) {

                        // Parse JSON response
                        let respJsonFileArray = JSON.parse(body);
                        let page = 1;

                        respJsonFileArray.forEach((url) => {
                            var localFileName = `./page${page}.png`;
                            var file = fs.createWriteStream(localFileName);
                            https.get(url, (response2) => {
                                response2.pipe(file)
                                    .on("close", () => {
                                        console.log(`Generated PNG file saved as "${localFileName} file."`);
                                    });
                            });
                            page++;
                        }, this);

                    });
            }
            else {
                console.log(`Operation ended with status: "${data.status}".`);
            }
        })
    });
}

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package.json

      {
  "name": "test",
  "version": "1.0.0",
  "description": "PDF.co",
  "main": "app.js",
  "scripts": {
  },
  "keywords": [
    "pdf.co",
    "web",
    "api",
    "bytescout",
    "api"
  ],
  "author": "ByteScout & PDF.co",
  "license": "ISC",
  "dependencies": {
    "request": "^2.88.2"
  }
}