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

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

ConvertPdfToPngFromUploadedFile.js

/*jshint esversion: 6 */

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");

// The authentication key (API Key).
// Get your own by registering at https://app.pdf.co/documentation/api
const API_KEY = "***********************************";

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


function getPresignedUrl(apiKey, localFile) {
    return new Promise(resolve => {
        // Prepare request to `Get Presigned URL` API endpoint
        let queryPath = `/v1/file/upload/get-presigned-url?contenttype=application/octet-stream&name=${path.basename(SourceFile)}`;
        let reqOptions = {
            host: "api.pdf.co",
            path: encodeURI(queryPath),
            headers: { "x-api-key": API_KEY }
        };
        // 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(apiKey, 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(apiKey, uploadedFileUrl, password, pages) {
    // Prepare URL for `PDF To PNG` API call
    var queryPath = `/v1/pdf/convert/to/png?password=${password}&pages=${pages}&url=${uploadedFileUrl}&async=True`;
    let reqOptions = {
        host: "api.pdf.co",
        path: encodeURI(queryPath),
        method: "GET",
        headers: { "x-api-key": API_KEY }
    };
    // 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) {
                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 = `/v1/job/check?jobid=${jobId}`;
    let reqOptions = {
        host: "api.pdf.co",
        path: encodeURI(queryPath),
        method: "GET",
        headers: { "x-api-key": API_KEY }
    };

    https.get(reqOptions, (response) => {
        response.on("data", (d) => {
            response.setEncoding("utf8");
            // Parse JSON response
            let data = JSON.parse(d);

            if (data.Status == "InProgress") {
                // Check again after 2 seconds
                setTimeout(function(){checkIfJobIsCompleted(jobId, resultFileUrlJson)} , 2000);
            }
            else if (data.Status == "Finished") {

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

                        //* workaround for issue with non supoprted firstchar code
                        var firstCharCode = body.charCodeAt(0);
                        if (firstCharCode == 65279) {
                            body = body.substring(1);
                        }

                        // 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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