WebAssembly
===========
[](http://en.wikipedia.org/wiki/Beauty)
[](https://travis-ci.org/herenowcoder/webassembly)
[](https://coveralls.io/r/herenowcoder/webassembly)
[](https://hex.pm/packages/webassembly)
[](https://hex.pm/packages/webassembly)
DSL for creating html structure straight with Elixir blocks:
```Elixir
use WebAssembly
builder do
html do
head do
meta http_equiv: "Content-Type", content: "text/html"
title "example"
end
body do
div class: "container", id: :content do
ul do
for index <- 1..3, do:
li "item #{index}"
end
random = :random.uniform(10)
if random == 5 do
text "Lucky! You got five"
end
end
span [style: "smiling"], "that was nice"
end
end
end
```
This results in a deeply nested list (aka [iolist])
which you can flatten or (better!) send to the socket as it is
([via Plug & Cowboy][via-plug] for example).
Now what can be concluded from the example above:
* you produce HTML elements by using macros inside `builder` block
* [non-void] element can be used with "flat" content argument or with a `do`-block
* element with a `do`-block means nesting
* inside such a `do`-block you have access to **full Elixir syntax**
* element attributes go first (but are optional), then the content
* attributes are Elixir keywords
* underscores in attribute keys are translated to dash signs
* you can omit brackets around attributes when using `do`-block,
but not when using flat form
* [void] HTML elements correspond to macros with attributes only,
like `meta` above
* if you want to emit just text without surrounding html tags,
simply use `text` macro.
For me it's beautiful. What about you?
## Why?
* to have views in pure Elixir, without HTML templates
* to utilize Erlang's approach: you can feed sockets with iolists
instead of one big binary produced by template engine
You can possibly mix different styles: code small snippets in
WebAssembly and feed them to your partial templates, finally using
your template engine to render the whole page.
## Usage
WebAssembly is published on [Hex], so just add `{:webassembly, "~> 0.5.0"}`
to your deps and `:webassembly` to your apps in the `mix.exs`.
Using it with [Plug] is a no-brainer - you just pass the doc to `send_resp/3`:
```Elixir
defmodule Plugged do
import Plug.Conn
use Plug.Router
use WebAssembly
plug :match
plug :dispatch
get "/" do
doc = builder do
html do
body do
text "hello from Plug!"
end
end
end
conn
|> put_resp_content_type("text/html")
|> send_resp(200, doc)
end
end
```
API details are available at [hexdocs].
## TDD
WebAssembly aims to have 100% [test coverage][cov].
## Type Safety
As for releases `0.3.0` and above WebAssembly [dialyzes][dia] with no warnings.
## Thanks
Loosely inspired by [Markaby].
## License
The code is released under the BSD 2-Clause License.
[markaby]: http://markaby.github.io/
[plug]: http://hex.pm/packages/plug
[cowboy]: http://hex.pm/packages/cowboy
[iolist]: http://www.erlang.org/doc/reference_manual/typespec.html
[hex]: http://hex.pm
[void]: http://www.w3.org/TR/html5/syntax.html#void-elements
[non-void]: http://www.w3.org/TR/html-markup/syntax.html#elements-html-syntax-list
[hexdocs]: http://hexdocs.pm/webassembly
[cov]: https://coveralls.io/r/herenowcoder/webassembly
[dia]: https://github.com/fishcakez/dialyze
[via-plug]: https://github.com/herenowcoder/webassembly#usage
