Programming Articles

In the last two parts of this article series, you created a web server using Node.js, Express, and JavaScript. You built a series of API routes to retrieve an array of products and a single product, searched for a set of products, and added, edited, and deleted products. The product data was retrieved from a connection to a SQL Server database. In this article, part three of the series, you'll build a website using Node.js and Express to serve web pages. You're going to see how to use a templating engine, Mustache, to create dynamic web pages from the data retrieved from API calls. To communicate from your website to your Web API server, you must configure cross-domain resource sharing (CORS). You'll see how to enable CORS in your Web API project. You'll then build a set of search, add, edit, and delete pages that make calls to your Web APIs.

In Part 1 of this article series, you created a web server using Node.js, Express, and JavaScript. You built a series of API routes used to retrieve an array of product objects, search for a single object or a set of objects, and add, edit, and delete objects. In this article, you'll move some of the hard-coded values from the code into a configuration file and read those settings into your application. You're going to add middleware functions to handle exceptions. You're going to write different types of errors to different locations, such as to the console and to a file. Thus far, the set of product data coming from the API calls has been from a JSON file. In this article, you'll learn to retrieve the same data, but from a SQL Server table.

Many developers use JavaScript to add client-side functionality to their web pages. JavaScript can be used to create server-side web pages and Web APIs too. In this three-part article series, you're introduced to Node.js and Express and you'll learn their roles in the creation of a web server. You're going to build a new web server from scratch, create some routes to return data, and learn how to modularize your web application. You'll be guided step-by-step to creating a set of APIs to return an array of objects or a single object, search for a set of objects, and add, edit, and delete objects. If you've never used Node.js or Express to build a server, don't worry: this article has everything you need to learn the basics of working with these two powerful tools.

Sometimes you need to upload files to your server from an Angular application to a Web API method. There are many ways to upload a file. In this article, I'm going to present a method that works well for small files, up to about one or two megabytes in size. You're going to build two projects; a .NET Core Web API project and an Angular project. You'll build these two projects from scratch using the Angular CLI, .NET Core, and the Visual Studio Code editor.

In the last two articles about CRUD and HTML (CODE Magazine, November/December 2015 and January/February 2016), you created a product information page to display a list of product data returned from a Web API. In addition, you built functionality to add, update, and delete products using the same Web API controller. In those two articles, there was a very basic exception handler function named handleException. This function displays error information returned from the API in an alert dialog on your page, as shown in Figure 1.

In my last article (CODE Magazine, November/December 2015), I showed you how to manipulate data in an HTML table using only JavaScript and jQuery. There were no post-backs, so the data didn't go anywhere. In this article, you'll use the same HTML and jQuery, but add calls to a Web API to retrieve and modify product data. It isn't necessary to go back and read the previous article; this article presents all of the HTML and the calls to work client-side and add the server-side code as well. I'll be using Visual Studio and .NET to build the Web API service, but the client-side coding is generic and can call a Web API built in any language or platform.