# Liquid [](https://hex.pm/packages/liquid) [](https://hex.pm/packages/liquid) [](https://travis-ci.org/bettyblocks/liquid-elixir)
It's a templating library for Elixir.
Continuation of the fluid liquid conversion.
## Usage
Add the dependency to your mix file:
``` elixir
# mix.exs
defp deps do
[…,
{:liquid, "~> 0.8.0"}]
end
```
You can either start the application directly:
`Liquid.start`
Or start it with your application:
``` elixir
# mix.exs
def application do
[mod: {MyApp, []},
applications: […, :liquid]]
end
```
Compile a template from a string:
`template = Liquid.Template.parse("{% assign hello='hello' %}{{ hello }}{{world}}")`
Render the template with a keyword list representing the local variables:
`{ :ok, rendered, _ } = Liquid.Template.render(template, %{"world" => "world"})`
For registers you might want to use in custom tags you can assign them like this:
`{ :ok, rendered, _ } = Liquid.Template.render(template, %{"world" => "world"}, registers: %{test: "hallo")`
The tests should give a pretty good idea of the features implemented so far.
## Custom tags and filters
You can add your own filters and tags/blocks inside your project:
``` elixir
defmodule MyFilters do
def meaning_of_life(_), do: 42
def one(_), do: 1
end
defmodule ExampleTag do
def parse(%Liquid.Tag{}=tag, %Liquid.Template{}=context) do
{tag, context}
end
def render(output, tag, context) do
number = tag.markup |> Integer.parse |> elem(0)
{["#{number - 1}"] ++ output, context}
end
end
defmodule ExampleBlock do
def parse(b, p), do: { b, p }
end
```
and than include them in your `config.exs` file
``` elixir
# config.exs
config :liquid,
extra_filter_modules: [MyFilters],
extra_tags: %{minus_one: {ExampleTag, Liquid.Tag},
my_block: {ExampleBlock, Liquid.Block}}
```
Another option is to set up the tag using:
`Liquid.Registers.register("minus_one", MinusOneTag, Tag)` for tag
`Liquid.Registers.register("my_block", ExampleBlock, Liquid.Block)` same for blocks;
and for filters you should use
`Liquid.Filters.add_filters(MyFilters)`
#### Global Filters
It's also possible to apply global filter to all rendered variables setting up the config:
``` elixir
# config.exs
config :liquid,
global_filter: &MyFilter.counting_sheeps/1
```
or adding a `"global_filter"` value to context for `Liquid.Template.render` function:
`Liquid.Template.render(tpl, %{global_filter: &MyFilter.counting_sheeps/1})` (you need to define filter function first)
## File systems
You can also set up the desired default file system for your project using the `config.exs` file
``` elixir
# config.exs
config :liquid,
file_system: {Liquid.LocalFileSystem, "/your/path"}
```
## Context assignment
`Liquid.Matcher` protocol is designed to deal with your custom data types you want to assign
For example having the following struct:
``` elixir
defmodule User do
defstruct name: "John", age: 27, about: []
end
```
You can describe how to get the data from it:
``` elixir
defimpl Liquid.Matcher, for: User do
def match(current, ["info"|_]=parts) do
"His name is: "<> current.name
end
end
```
And later you can use it in your code:
``` elixir
iex> "{{ info }}" |> Liquid.Template.parse |> Liquid.Template.render(%User{}) |> elem(1)
"His name is: John"
```
## Missing Features
Feel free to add a bug report or pull request if you feel that anything is missing.
### todo
* Fix empty check on arrays
