How to Install a Node Module and Call it from a Node Service in a Web Application

Description

Node modules can be downloaded and used in Alpha Anywhere web applications.

Discussion

Web Applications can call methods in Node.js modules from server-side Xbasic. The Node_request() function can be used to call a node service from a web application. For example, suppose you have created the following node module saved as tinify.js inside the node_services directory:

var tinify = require("tinify");
tinify.key = "apikey goes here";
exports.handler = function (packet, response, sendResponse) {
    var source = tinify.fromFile(packet.infile).resize(packe.resize).toFile(packet.outfile,function(err) {
        if (err) {
            response.error = err.message;
        }
        sendResponse(response,null);
    });
};

The node service defined above can be called from Xbasic, such as in an .a5w page, as follows:

<%A5
dim req as p
dim req.infile as c = "C:\movieImages\snow.jpg"
dim req.outfile as c = "C:\movieImages\snowSmall.jpg"
dim req.resize.method as c = "fit"
dim req.resize.width as n = 100
dim req.resize.height as n = 200

if file.exists(req.outfile) then
    file.remove(req.outfile)
end if

? node_request("tinify",req)

if file.exists(req.outfile) then
    ? "Thumbnail was created"
else
    ? "Thumbnail was *not* created"
end if
%>

In the videos below, we demonstrate how to download the tinify Node Module using NPM and add it to your web project. We then show how to create a Node Service to call the tinify package from an .a5w page.

Installing a Node Module from NPM and then Creating a Node Service to Call Methods in the Node Module