(Node.js) Extract data:image/png;base64 from HTML

Demonstrates how to extract base64 image data from HTMl and save to files.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    var sb = new chilkat.StringBuilder();
    var bd = new chilkat.BinData();
    var sbFilename = new chilkat.StringBuilder();
    var index = 1;

    var success = sb.LoadFile("qa_data/html/oresp body.txt","utf-8");
    // Assume success.
    console.log("length = " + sb.Length);

    var mayHaveMore = true;
    while (mayHaveMore == true) {

        // Get the base64 between the 1st occurrence "data:image/png;base64," and "'"
        var sBase64 = sb.GetBetween("data:image/png;base64,","'");

        // If nothing is found, then we'll exit the loop because there are no more.
        mayHaveMore = sb.LastMethodSuccess;

        if (sb.LastMethodSuccess == true) {
            // Found something.
            // Load into bd and save.
            success = bd.LoadEncoded(sBase64,"base64");

            sbFilename.SetString("qa_output/png_");
            sbFilename.AppendInt(index);
            sbFilename.Append(".png");

            bd.WriteFile(sbFilename.GetAsString());

            // Replace "data:image/png;base64" with "data:image-png;base64" so the next iteration finds the next occurrence.
            sb.ReplaceFirst("data:image/png;base64","data:image-png;base64");
        }

        index = index+1;
    }

    // Restore our replacements..
    var count = sb.Replace("data:image-png;base64","data:image/png;base64");

    console.log("All done.");

}

chilkatExample();