Haparanda

by Matijs van Zuijlen

Description

Pure Ruby Handlebars Parser using upstream .l and .y files

Usage

require "haparanda"

hbs = Haparanda::Compiler.new
hbs.register_partial 'full_name', "{{person.first_name}} {{person.last_name}}"
hbs.register_helper :foo do |context, bar, baz, options|
  ...
end
template = hbs.compile(template_text) # Returns Haparanda::Template
template.call input  # or template.call({ foo: "Bar", baz: "Qux" })

Goals

Fast parsing
Implement all of handlebars

Compatibility Notes

When using a hash as input, symbols keys and string keys are considered different
Currently targets handlebars.js master

Install

gem install haparanda

Related Work

The handlebars gem is a wrapper around the JavaScript library. It seems to support all of handlebars. However, it requires a separate javascript runtime and suffers from memory leaks.

handlebars-rb uses the following API:
```
handlebars = Handlebars::Context.new
handlebars.register_helper(:foo) do
  ...
end
template = handlebars.compile("{{say}} {{what}}")
template.call(:say => "Hey", :what => "Yuh!") #=> "Hey Yuh!"
```
Alternative gems that also use the JavaScript implementation are handlebars_exec, minibars and handlebars-engine.

ruby-handlebars is a pure Ruby handlebars parser that uses the parslet gem for parsing. Parsing is slow for large templates and it does not implement whitespace handling.

It uses the following API:

hbs = Handlebars::Handlebars.new
hbs.register_partial('full_name', "{{person.first_name}} {{person.last_name}}")
hbs.register_helper(:foo) do |context, bar, baz, block, else_block|
  ...
end
template = hbs.compile("Hello {{> full_name}}")
template.call({person: {first_name: 'Pinkie', last_name: 'Pie'}})

curlybars is a pure Ruby parser aimed at using handlebars templates with Rails. It uses RLTK for parsing and supports a subset of handlebars. In particular, it seems custom block helpers are not supported.
FlavourSaver is a pure Ruby Handlebars parser that also uses RLTK. It provides a Tilt based interface. This is the most complete Ruby implementation of Handlebars but unfortunately parsing is slow.
Steering is a compiler for handlebars templates. Also uses the JavaScript handlebars implementation.

License

Haparanda is free software, distributed under the terms of the GNU Lesser General Public License, version 2.1 or later. See the file COPYING.LIB for more information.

Several files are based on code from handlebars-js and handlebars-parser. These are each individually marked in comments at the top of the file.

Handlebars-js is released under the MIT license:

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

handlebars-parser is released under the ICS license.

haparanda

Runtime