(JavaScript) Extract data:image/png;base64 from HTML

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

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

var sb = new CkStringBuilder();
var bd = new CkBinData();
var sbFilename = new CkStringBuilder();
var index = 1;

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.");