GettingStarted.md

Getting Started with ElixirScript

The intent of this guide is to get you started with ElixirScript. It will give you instructions on using ElixirScript. I will go over the three ways you can use ElixirScript:

• As an escript
• As a mix task
• As a library in your application

Escript

OSX: Elixirscript can be installed via homebrew brew install elixirscript. For everyone else, plase read below

• Step 1: Get escript

  You can download the elixirscript escript from the releases page on github. It is a tar file named elixirscript.tar.gz.

• Step 2: Untar

  Next, untar elixirscript.tar.gz

  tar -xvzf elixirscript.tar.gz

  You will want to put the bin folder from the uncompressed folder into your path. This should allow you to use the elixirscript escript.

• Step 3: Use

  This is the help output of elixirscript

  usage: elixirscript <input> [options]
  <input> path to elixir files or the elixir code string if the -ex flag is used
  
  options:
  -o  --output [path]   places output at the given path
  -ex --elixir          read input as elixir code string
  -r  --root [path]     root import path for all exported modules
  --std-lib [path]      outputs the elixirscript standard library JavaScript files to the specified path
  --full-build          informs the compiler to do a full build instead of an incremental one
  only used when output is specified
  --core-path    es6 import path to the elixirscript standard lib
  only used with the [output] option. When used, Elixir.js is not exported
  -v  --version         the current version number
  -h  --help            this message

  the <input> is the elixir code string or file path you want to convert from elixir to javascript. Below is an example of using a code string and turning it into JavaScript

  $ elixirscript ":atom" -ex
  Symbol.for('atom')

  The elixirscript escript changed the elixir code, :atom into the JavaScript code Symbol.for('atom'). The -ex parameter lets the script know that the input is an Elixir code string instead of a file.

  What if we wanted to give it a file? You would simply do the following:

  $ elixirscript "example.exjs"
  Symbol.for('atom')

  NOTE: ElixirScript files must have the extension, .exjs

  What you will have noticed by now is that it has output everything we've done so far to the terminal. What about if we want to place the output to a path? The next example takes a file as input and outputs the result in another directory.

  $ elixirscript "example.exjs" -o "dist"

  If you look in the dist folder, you should see example.js as well as elixir.js. elixir.js is the JavaScript file that contains the Elixir Standard library. In example.js, the first line should be an import statement importing elixir.js for use.

  wildcards are also accepted:

  $ elixirscript "src" -o "dist"

  The last option we will show is the root option. This option is for defining a root path for the import statements. By default your import statement will not have anything prepended to it. For example, the elixir import will look like this:

  import * as Elixir from 'elixir';

  If we wanted to prepend "js" to the root, we can like this:

  $ elixirscript "example.exjs" -o "dist" -r "js"
  

  Now the import will look like this:

  import * as Elixir from 'js/elixir';

  That concludes the walkthrough on options, as well as the walkthrough on using the elixirscript escript.

mix elixirscript

• Step 1: Get dependency

  The first step is getting the dependency. In your mix.exs file for your elixir project, add elixir_script to your deps.

  {:elixir_script, "~> 0.18"}

• Step 2: Now download the dep

  $ mix deps.get

  Now you should have the mix task, elixirscript.

• Step 3: Use

  $ mix elixirscript "example.exjs" -o "dist" -r "js"

  What you will notice is that the parameters are exactly the same as the escript.

ElixirScript module

• Step 1: Get dependency

  The first step is getting the dependency. In your mix.exs file for your elixir project, add elixir_script to your deps.

  {:elixir_script, "~> 0.22"}

• Step 2: Now download the dep

  $ mix deps.get

• Step 3: Use Now you will be able to use the ElixirScript module within your code.

  ElixirScript.compile(":atom")

  The is also compile_path/2 and compile_quoted/2. Each of the functions take an options keyword list.

Macros

Macros must be defined in either a .ex or .exs file. These will be loaded at compile time and whenever an import or require expression is found, if the module specified is loaded, it will use it to expand macros within the lexical scope.

Appendix

Using JavaScript Modules

You can use alias, import, and require as you would in Elixir.

For JavaScript modules, you use must JS.import

JS.import A, "a" #translates to "import {default as A} from 'a'"

JS.import [A, B, C], "a" #translates to "import {A, B, C} from 'a'"

Frontend Project Boilerplate

There is an elixirscript frontend boilerplate project. This setup uses gulp and brunch to build and bundle assets.

ElixirScript-Brunch

There is an Brunch plugin, ElixirScript-Brunch. There are instructions there on how to use it with Phoenix.