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chapters/basic-app.md

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 # A Basic Dancer Web App
+
+In this chapter we will get the most basic Dancer2 application up and
+running. It will take about a minute.
+
+## Generating an App
+
+Dancer2 comes with a command line program which allows you to start a
+new application easily. It's called `dancer2` and you run it like
+this:
+
+    $ dancer2 gen -a [AppName]
+
+Our application is a Todo list. So we'll call it "Todo" and run
+`dancer2` like this:
+
+    $ dancer2 gen -a Todo
+
+This command will create a directory called `Todo` and will write a
+lot of new files into that directory - telling you what it is doing as
+it does it. I got the following output:
+
+    + Todo
+    + Todo/cpanfile
+    + Todo/Makefile.PL
+    + Todo/MANIFEST.SKIP
+    + Todo/config.yml
+    + Todo/.dancer
+    + Todo/public
+    + Todo/public/dispatch.fcgi
+    + Todo/public/500.html
+    + Todo/public/dispatch.cgi
+    + Todo/public/favicon.ico
+    + Todo/public/404.html
+    + Todo/public/images
+    + Todo/public/images/perldancer-bg.jpg
+    + Todo/public/images/perldancer.jpg
+    + Todo/public/css
+    + Todo/public/css/style.css
+    + Todo/public/css/error.css
+    + Todo/public/javascripts
+    + Todo/public/javascripts/jquery.js
+    + Todo/t
+    + Todo/t/001_base.t
+    + Todo/t/002_index_route.t
+    + Todo/lib
+    + Todo/lib/Todo.pm
+    + Todo/views
+    + Todo/views/index.tt
+    + Todo/views/layouts
+    + Todo/views/layouts/main.tt
+    + Todo/environments
+    + Todo/environments/production.yml
+    + Todo/environments/development.yml
+    + Todo/bin
+    + Todo/bin/app.psgi
+
+We'll look in more detail at these files soon, but firstly, let's run
+our new Dancer2 app. Because what `dancer2` has given us is already a
+runnable application. It doesn't do much yet, but that's what the rest
+of this book is for.
+
+Dancer2 (like most modern Perl web frameworks) is based on a protocol
+called PSGI (Perl Server Gateway Interface). PSGI allows us to write
+web applications that are completely independent of their deployment
+environment and this makes it far easier to write, debug and test web
+applications that it has ever been before. There is also a toolkit for
+working with PSGI applications which is called Plack. And we need to
+turn to Plack in order to demonstrate our new web application working.
+
+At the bottom of our list of new files, you'll see `app.psgi`. That is
+the actual program that is used to run our application. Just drop that
+file into any PSGI-aware environment to make your web application
+available. But what do I mean by a "PSGI-aware environment"? Well,
+we'll look into that in more detail later on, but, for now, we'll use
+a program called `plackup` which is part of the Plack toolkit and
+allows use to run a PSGI application very easily. Simply run this on a
+command line:
+
+    $ plackup bin/app.psgi
+
+If all is well, then you'll see the following:
+
+    HTTP::Server::PSGI: Accepting connections at http://0:5000/
+
+This tells us that `plackup` is using HTTP::Server::PSGI to run a web
+server which is running on our local system and listening on
+port 5000. If you open a web browser and visit http://localhost:5000/
+you will see your web application looking like this:
+
+![](img/step01.png)