Node.js

Decode Base64 Image String (GIF, JPG, etc.) and Save to File

I have an XML response that includes a base 64 encoded image string (UPS label). It's a huge string and I need to save it as a gif file on my users pc.

This example shows how to do it..

Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    var bd = new chilkat.BinData();

    // I created an extra-small GIF image for this example..
    success = bd.LoadFile("qa_data/gif/xsmall.gif");
    if (success !== true) {
        console.log("Failed to load GIF image file.");
        return;
    }

    // Show GIF bytes as base64:
    console.log(bd.GetEncoded("base64"));

    // This particular GIF in base64 is this:
    // R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7

    // Let's begin with an XML string:
    var x = "<abc><def>R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7</def></abc>";

    var xml = new chilkat.Xml();
    success = xml.LoadXml(x);

    // Get the base64 string:
    var gifBase64 = xml.GetChildContent("def");

    console.log(gifBase64);

    // Load bd with the base64 decoded bytes.  
    bd.Clear();
    bd.AppendEncoded(gifBase64,"base64");

    // Save to a GIF file.
    success = bd.WriteFile("qa_output/xsmall.gif");

}

chilkatExample();