GenieFramework Microblog Part 1

Introduction

Quite some time ago I started attempting to learn python and web development. I claim in no way to be even close to an expert on either one of those things, in fact I am truly a beginner at both. While I never continued with python I have always enjoyed web development, creating quite a few small R Shiny apps along the way. As I have decided to learn Julia I am instantly drawn to Web Development, and I decided to try out the Genie Framework. While there exist some tutorials on the web, I find the all contain small pieces of information but lack putting everything together. Form my learning python days, I know that there exists a WONDERFUL tutorial for the python Flask framework (Found Here). I decided to challenge myself and recreate his website using Genie, and the Model, View, Controller model. I will attempt to document what I do to try and help others along the way. As stated above I AM NOT AN EXPERT, so at any time there is a good chance I am not doing something the best way possible! I encourage everyone to follow along and make suggestions for improvements. I am going to try my best to go in the order Miguel did, but for some chapters I will skip sections or combine things as needed to make them work for the framework.

Getting Started

Miguel’s blog does a great job of going into installing python and flask as well as setting up virtual environments in python. I am going to skip most of this as there is great documentation out there on how to install Julia and set up a project (Genie will actually take care of this for us). Instead I will link here what I would say are the three prerequisites for getting started.

• Download and install Julia
• The IDE of your choice (I use VSCode, and the Julia Extension)
• Add Genie to your Julia environment (see below)

To add Genie to your Julia environment, open the Julia REPL and type the following:

pkg> add Genie # press ] from julia> prompt to enter Pkg mode

Creating The App

Genie will take care of creating a new directory for us, but we will want to open the Julia REPL from whatever directory we want the app folder to live in. Once that has been decided open a Julia REPL and type the following:

julia> using Genie

julia> Genie.Generator.newapp("Microblog")

Upon executing the command, Genie will:

• make a new dir called Microblog and cd() into it,
• install all the app’s dependencies
• create a new Julia project (adding the Project.toml and Manifest.toml files),
• activate the project,
• automatically load the new app’s environment into the REPL,
• start the web server on the default Genie port (port 8000) and host (127.0.0.1 – aka localhost).

At this point you can confirm that everything worked as expected by visiting http://127.0.0.1:8000 in your favorite web browser. You should see Genie’s welcome page. If at any point you want to exit the REPL and reload the app perform the following:

julia> using Genie

julia> Genie.loadapp()

julia> up()

This will reload the app and activate the web server. You can again visit http://127.0.0.1:8000 to test that everything is working.

Creating a Hello World Genie App

While Genie by default has a welcome page, lets change it to a simple Hello World page to make the app our own. Open routes.jl and change the “/” route to the following:

routes.jl

route("/") do
  "Hello World!"
end

If we go to http://127.0.0.1:8000 we should now see the following:

Hello World Screenshot