hmote

Minimal template engine with default escaping.

Description

HMote is based on Mote and uses Hache to auto-escape HTML special characters.

Basic Usage

This is a basic example:

require "hmote"

template = HMote.parse("your template goes here!")
template.call
# => "your template goes here!"

HMote recognizes two tags to evaluate Ruby code: % and {{}}. The difference between them is that while the % tag only evaluates the code, the {{}} tag also prints the result to the template.

Imagine that your template looks like this:

% gems = ["rack", "cuba", "hmote"]

<ul>
% # this is a comment.
% gems.sort.each do |gem|
  <li>{{ gem }}</li>
% end
</ul>

The generated result will be:

<ul>
  <li>cuba</li>
  <li>hmote</li>
  <li>rack</li>
</ul>

Parameters

The values passed to the template are available as local variables:

template = HMote.parse("Hello {{ name }}", self, [:name])
template.call(name: "Ruby")
# => Hello Ruby

You can also use the params local variable to access the given parameters:

template = HMote.parse("Hello {{ params[:name] }}", self)
template.call(name: "Ruby")
# => Hello Ruby

Auto-escaping

By default, HMote escapes HTML special characters to prevent XSS attacks. You can start the expression with an exclamation mark to disable escaping for that expression:

template = HMote.parse("Hello {{ name }}", self, [:name])
template.call(name: "<b>World</b>")
# => Hello &lt;b&gt;World&lt;b&gt;

template = HMote.parse("Hello {{! name }}", self, [:name])
template.call(name: "<b>World</b>")
# => Hello <b>World</b>

HMote::Helpers

There's a helper available in the HMote::Helpers module, and you are free to include it in your code. To do it, just type:

include HMote::Helpers

Using the hmote helper

The hmote helper receives a file name and a hash and returns the rendered version of its content. The compiled template is cached for subsequent calls.

hmote("test/basic.mote", n: 3)
# => "***\n"

Template caching

When the hmote helper is first called with a template name, the file is read and parsed, and a proc is created and stored in the current thread. The parameters passed are defined as local variables in the template. If you want to provide more parameters once the template was cached, you won't be able to access the values as local variables, but you can always access the params hash.

For example:

# First call
hmote("foo.mote", a: 1, b: 2)

HMote::Render

To use HMote in Cuba, you need to load the HMote::Render plugin as shown below:

require "hmote"
require "hmote/render"

Cuba.plugin(HMote::Render)

HMote::Render provides three helper methods for rendering templates: partial, view and render.

Cuba.define do
  on "about" do
    # `partial` renders a template without a layout.
    res.write partial("about")
  end

  on "home" do
    # `view` renders a template within a layout.
    res.write view("about")
  end

  on "contact" do
    # `render` is a shortcut to `res.write view(...)`
    render("contact")
  end
end

By default, HMote::Render assumes that all view templates are placed in a folder named views and that they use the .mote extension. Also for view and render methods, it assumes that the layout template is called layout.mote.

The defaults can be changed through the Cuba.settings method:

Cuba.settings[:hmote][:views] = "./views/admin/"
Cuba.settings[:hmote][:layout] = "admin"

Layouts

To render inner content into a layout, use the {{! content }} tag.

<html>
  <head>
    <title>Mote Layout</title>
  </head>
  <body>
    <h1>Hello, world!</h1>

    {{! content }}
  </body>
</html>

Helpers

You can use the app variable to access the application helpers.

Cuba.define do
  def h(unsafe)
    ...
  end
end
<h1>{{! app.h("unsafe") }}</h1>

{{ app.partial("list") }}

Installation

$ gem install hmote