Microsoft Web Platform Day

This week I spent a day with Microsoft at their Web Platform Day to learn about what's new with ASP.NET. Here are some notes I took back to my team of things we should look into implementing and some things that don't really fit into our platform but are interesting to know about.

Task Runners

Task Runners can be used to….run tasks! This is usually done as part of the build process for tasks such as minifying JavaScript and CSS. There are a few task runners out there such as Grunt, Gulp and Broccoli(?!) but Microsoft were recommending Gulp. These are integrated a bit better in more recent versions of Visual Studio and ASP.NET, but can be used in any web development project.

A few of the task plugins:

gulp-minify-css: minifies your CSS files removing comments, whitespace and new lines to reduce file size and make the site load quicker
gulp-uglify: minifies JavaScript and can also do stuff like shortening names of functions and variables in the minified version of your JavaScript to reduce file size
gulp-autoprefixer: some browsers implement their own CSS features which are prefixed with –webkit, -moz or –ms. This makes sure you have prefixes for all browsers if you use one of them
gulp-concat: bundles files into a single file (e.g. multiple CSS files into one, or multiple JavaScript files into one) to reduce number of requests made by the browser and improve performance
gulp-imagemin: Optimizes .png and .jpg images for the web

Tasks can be chained together in Gulp so that you could minify several CSS files and then concatenate into one. You can also set Gulp to watch for changes to files and run automatically when you make changes.

Performance & Best Practises

There are a few check-lists, site scanners and plugins that will check sites for performance and best practises. Site authentication often prevents site scanning websites from accessing sites but you can still check your work with a plugin such as YSlow. This will give a report with a rating for a page and a list of recommendations. Many of the recommendations are covered by the task runners mentioned above (minifying and concatenating). Another checklist worth reading through is http://webdevchecklist.com/.

Image sprites are a single image file containing multiple icons and CSS to pick out individual icons from the file. This reduces the number of HTTP requests made by the page and improves performance compared to requesting each image individually. Going even further, it is recommended that icon fonts are used, where appropriate, so that the icons can easily be scaled and their colour can be changed.

There are web.config changes that can be implemented for caching settings and compression of files but then ‘cache busting’ strategies should be investigated so that clients get the latest versions of files when caching is being used.

Entity Framework

Entity Framework is a Microsoft technology for working with databases and simplifies going between C# classes and database tables. It is recommended that you take a code first approach – write your classes, set up your database connection string and the tables can be automagically created in the database. You can create classes from an existing database but you can get into problems if you want to make database changes and then import again.

ASP.NET Web API

Used to create RESTful web services and integrates well with Entity Framework. A Visual Studio feature (‘scaffolding’) can automatically create web service methods for CRUD operations from your Entity Framework models. You can also easily add OData support to add filtering and sorting to you web services via a query string (e.g. “‘?$name eq ‘bob’”).

ASP.NET Smart Tags / Tag Helpers

These are ASP.NET tags used in your HTML which are rendered on the server. One example give was loading scripts based on the environment. This lets you deliver full JavaScript and CSS files in the development environment but minified versions in production.

Another example was fall-back href’s when loading scripts. You can refer to CDN versions of popular scripts such as jQuery to improve performance, but provide a fall-back URL to a version on your server if the CDN is not available or the file is no longer on the CDN.

Web Performance and Load Test

A new project template in Visual Studio 2015 allows you to simulate web site load and analyse results. The requests are generated from Azure so presumably there is a cost associated with it and I'm not sure how it would work with site authentication.

ASP.NET Core

Microsoft have released an open source version of ASP.NET which runs on Windows, Linux and OSX. This can handle as much as 8 times the traffic of an ASP.NET 4.6 site on the same server. This is largely achieved by allowing you to configure which pipeline features are used when handling requests. 

You can also ship your site bundled with the framework which avoids version dependency problems on the server.

Despite all of this goodness, it isn't finished yet and doesn't have a lot of the features of ASP.NET 4.6.

Azure

Some interesting Azure features were demonstrated.

Platform as a Service / Infrastructure as a Service:

With Infrastructure as a service, you get a virtual machine and look after the software, patches etc. With platform as a service, that is all handled for you and you just upload your code/content.

Deployment Slots:

You can set up deployment slots in Azure for different environments (dev, test, live etc.). You can also use slots for A/B testing or staged roll-out. You can easily switch slots around when you want to move from test to live.

Continuous Deployment:

Deployment slots can be linked to a source repository such as a GitHub branch and automatically update if code is committed to the repository.

Auto-Scale:

Azure can be set up to automatically scale to more servers (within set limits) when demand exceeds a specified threshold. It can also automatically scale down if demand drops below a set threshold. This lets you maintain availability without spending more than you need.

Azure Storage:

A cheap way to host static content with good performance.

Azure Cloud Explorer:

You can now debug code running on Azure from Visual Studio running locally.

Apps

There is a web standard being developed for a manifest file for web sites. Microsoft have a tool called ManifoldJS that uses this to generate app store apps for Windows, iOS, Android and Chrome from a website.