node-red-nodes/parsers/base64/70-base64.js

module.exports = function(RED) {
    "use strict";
    function Base64Node(n) {
        RED.nodes.createNode(this,n);
        this.action = n.action || "";
        this.property = n.property || "payload";
        var node = this;
        var regexp = new RegExp('^[A-Za-z0-9+\/=]*$');  // check it only contains valid characters

        this.on("input", function(msg) {
            var value = RED.util.getMessageProperty(msg,node.property);
            if (value !== undefined) {
                if (node.action === "str") {
                    value = RED.util.ensureBuffer(value).toString('base64');
                    RED.util.setMessageProperty(msg,node.property,value);
                    node.send(msg);
                }
                else if (node.action === "b64") {
                    if ( typeof value === "string") {
                        var load = value.replace(/\s+/g,'');
                        if (regexp.test(load) && (load.length % 4 === 0) ) {
                            value = Buffer.from(load,'base64').toString('binary');
                            RED.util.setMessageProperty(msg,node.property,value);
                            node.send(msg);
                        }
                        else { node.error("Invalid Base64 string",msg); }
                    }
                    else { node.error("Not a Base64 string",msg); }
                }
                else {
                    if (Buffer.isBuffer(value)) {
                        // Take binary buffer and make into a base64 string
                        value = value.toString('base64');
                        RED.util.setMessageProperty(msg,node.property,value);
                        node.send(msg);
                    }
                    else if (typeof value === "string") {
                        // Take base64 string and make into binary buffer
                        var load = value.replace(/\s+/g,'');      // remove any whitespace
                        //var load = value.replace(/[\t\r\n\f]+/g,'');
                        //var load = value;
                        if ( regexp.test(load) && (load.length % 4 === 0) ) {
                            value = Buffer.from(load,'base64');
                            RED.util.setMessageProperty(msg,node.property,value);
                            node.send(msg);
                        }
                        else {
                            node.log("Not a Base64 string - maybe we should encode it...");
                            value = Buffer.from(value).toString('base64');
                            RED.util.setMessageProperty(msg,node.property,value);
                            node.send(msg);
                        }
                    }
                    else {
                        node.warn("This node only handles strings or buffers.");
                    }
                }
            }
            else { node.warn("No property found to process"); }
        });
    }
    RED.nodes.registerType("base64",Base64Node);
}