# Erubi¶ ↑

Erubi is a ERB template engine for ruby. It is a simplified fork of Erubis, using the same basic algorithm, with the following differences:

- Handles postfix conditionals when using escaping (e.g. `<%= foo if bar %>`)

- Supports frozen_string_literal: true in templates via :freeze option

- Works with ruby's –enable-frozen-string-literal option

- Automatically freezes strings for template text when ruby optimizes it (on ruby 2.1+)

- Escapes ' (apostrophe) when escaping for better XSS protection

- Has 6x faster escaping on ruby 2.3+ by using cgi/escape

- Has 86% smaller memory footprint

- Does no monkey patching (Erubis adds a method to Kernel)

- Uses an immutable design (all options passed to the constructor, which returns a frozen object)

- Has simpler internals (1 file, <150 lines of code)

- Is not dead (Erubis hasn't been updated since 2011)

It is not designed with Erubis API compatibility in mind, though most Erubis ERB syntax works, with the following exceptions:

- No support for `<%===` for debug output

# Installation¶ ↑

    gem install erubi

# Source Code¶ ↑

Source code is available on GitHub at github.com/jeremyevans/erubi

# Usage¶ ↑

Erubi only has built in support for retrieving the generated source for a file:

    require 'erubi'
    eval(Erubi::Engine.new(File.read('filename.erb')).src)

Most users will probably use Erubi via Rails or Tilt. Erubi is the default erb template handler in Tilt 2.0.6+ and Rails 5.1+.

## Capturing¶ ↑

Erubi does not support capturing block output into the template by default. However, it comes with an `erubi/capture_end` file that supports capturing via `<%|=` and `<%|==` tags which are closed with a `<%|` tag:

    <%|= form do %>
      <input>
    <%| end %>

This offers similar functionality to that offered by Rails' `<%=` tags, but without the corner cases with that approach (which are due to attempting to parse ruby code via a regexp). Similar to the `<%=` and `<%==` tags, `<%|=` captures by default and `<%|==` captures and escapes by default, but this can be reversed via the `:escape_capture` or `:escape` options.

To use the capture_end support with tilt:

    require 'tilt'
    require 'erubi/capture_end'
    Tilt.new("filename.erb", :engine_class=>Erubi::CaptureEndEngine).render

# Reporting Bugs¶ ↑

The bug tracker is located at github.com/jeremyevans/erubi/issues

# License¶ ↑

MIT

# Authors¶ ↑

Jeremy Evans <code@jeremyevans.net> kuwata-lab.com