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YARD is a Ruby Documentation tool. The Y stands for "Yay!"
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= YARD Release 0.2.2 (June 16th 2008) 
Copyright 2007-2008 Loren Segal


YARD is a documentation generation tool for the Ruby programming language
( It enables the user to generate consistent, usable
documentation that can be exported to a number of formats very easily, and
also supports extending for custom Ruby constructs such as custom class level 
definitions. Below is a summary of some of YARD's notable features.

1. <b>RDoc/SimpleMarkup Formatting Compatibility</b>: YARD is made to be compatible   
   with RDoc formatting. In fact, YARD does no processing on RDoc documentation  
   strings, and leaves this up to the output generation tool to decide how to    
   render the documentation.                                                     

2. <b>Yardoc Meta-tag Formatting Like Python, Java, Objective-C and other        
   languages</b>: YARD uses a '@tag' style definition syntax for meta tags alongside 
   regular code documentation. These tags should be able to happily sit side by  
   side RDoc formatted documentation, but provide a much more consistent and     
   usable way to describe important information about objects, such as what      
   parameters they take and what types they are expected to be, what type a      
   method should return, what exceptions it can raise, if it is deprecated, etc..
   It also allows information to be better (and more consistently) organized     
   during the output generation phase. Some of the main tags are listed below:   
   <b>Table 1. Meta-tags and their descriptions</b>                                    
   <tt>@param [Types] name description</tt>::
     Description Allows for the definition of a method parameter with 
     optional type information.
   <tt>@yieldparam [Types] name description</tt>::
     Description Allows for the definition of a method parameter to a
     yield block with optional type information.
   <tt>@yield description</tt>::                                        
     Allows the developer to document the purpose of a yield block in 
     a method.
   @return [Types] description</tt>::
     Describes what the method returns with optional type information.

   <tt>@deprecated description</tt>::
     Informs the developer that a method is deprecated and should no 
     longer be used. The description offers the developer an alternative 
     solution or method for the problem.
   <tt>@raise class description</tt>::
     Tells the developer that the method may raise an exception and of 
     what type. 
   <tt>@see name</tt>::
     References another object, URL, or other for extra information. 

   <tt>@since number</tt>::
     Lists the version number in which the object first appeared. 

   <tt>@version number</tt>::
     Lists the current version of the documentation for the object. 

   <tt>@author name</tt>::
     The authors responsible for the module

   You might have noticed the optional "types" declarations for certain tags.    
   This allows the developer to document type signatures for ruby methods and    
   parameters in a non intrusive but helpful and consistent manner. Instead of   
   describing this data in the body of the description, a developer may formally 
   declare the parameter or return type(s) in a single line. Consider the        
   following Yardoc'd method:                                                    

     # Reverses the contents of a String or IO object. 
     # @param [String, #read] contents the contents to reverse 
     # @return [String] the contents reversed lexically 
     def reverse(contents) 
       contents = if respond_to? :read 
   With the above @param tag, we learn that the contents parameter can either be
   a String or any object that responds to the 'read' method, which is more      
   powerful than the textual description, which says it should be an IO object.  
   This also informs the developer that they should expect to receive a String   
   object returned by the method, and although this may be obvious for a         
   'reverse' method, it becomes very useful when the method name may not be as   
3. <b>Custom Constructs and Extensibility of YARD</b>: Take for instance the example:        
     class A 
       class << self 
         def define_name(name, value) 
           class_eval "def #{name}; #{value.inspect} end" 
       # Documentation string for this name 
       define_name :publisher, "O'Reilly"
   This custom declaration provides dynamically generated code that is hard for a
   documentation tool to properly document without help from the developer. To   
   ease the pains of manually documenting the procedure, YARD can be extended by 
   the developer to handled the 'define_name' construct and add the required     
   method to the defined methods of the class with its documentation. This makes 
   documenting external API's, especially dynamic ones, a lot more consistent for
   consumption by the users.                                                     
4. <b>Raw Data Output</b>: YARD also outputs documented objects as raw data (the      
   dumped Namespace) which can be reloaded to do generation at a later date, or  
   even auditing on code. This means that any developer can use the raw data to  
   perform output generation for any custom format, such as YAML, for instance.  
   While YARD plans to support XHTML style documentation output as well as       
   command line (text based) and possibly XML, this may still be useful for those
   who would like to reap the benefits of YARD's processing in other forms, such 
   as throwing all the documentation into a database. Another useful way of      
   exploiting this raw data format would be to write tools that can auto generate
   test cases, for example, or show possible unhandled exceptions in code.       

== USAGE                                                                        

There are a couple of ways to use YARD. The first is via command-line, and the
second is the Rake task. There are also the +yard-graph+ and +yri+ binaries to
look at, if you want to poke around.

=== 1. yardoc Command-line Tool

The most obvious way to run YARD is to run the +yardoc+ binary file that comes
with YARD. This will, among other things, generate the HTML documentation for
your project code. You can type <tt>yardoc --help</tt> to see the options
that YARD provides, but the easiest way to generate docs for your code is to
simply type +yardoc+ in your project root. This will assume your files are
located in the +lib/+ directory. If they are located elsewhere, you can specify
paths and globs from the commandline via:

  yardoc 'lib/**/*.rb' 'app/**/*.rb' ...etc...
The tool will generate a +.yardoc+ file which will store the cached database
of your source code and documentation. If you want to re-generate your docs
with another template you can simply use the <tt>--use-cache</tt> (or -c) 
option to speed up the generation process by skipping source parsing.

YARD will by default only document code in your public visibility. You can
document your protected and private code by adding <tt>--protected</tt> or
<tt>--private</tt> to the option switches.

=== 2. Rake Task

The second most obvious is to generate docs via a Rake task. You can do this by 
adding the following to your +Rakefile+: do |t|
    t.files   = ['lib/**/*.rb', OTHER_PATHS]   # optional
    t.options = ['--any', '--extra', '--opts'] # optional
both the +files+ and +options+ settings are optional. +files+ will default to
<tt>lib/**/*.rb</tt> and +options+ will represents any options you might want
to add. Again, a full list of options is available by typing <tt>yardoc --help</tt>
in a shell. You can also override the options at the Rake command-line with the
OPTS environment variable:

  > rake yardoc OPTS='--any --extra --opts'
=== 3. yri RI Implementation

The yri binary will use the cached .yardoc database to give you quick ri-style
access to your documentation. It's way faster than ri but currently does not
work with the stdlib or core Ruby libraries, only the active project. Example:

  > yri YARD::Handlers::Base#register
  > yri File::relative_path

=== 4. yard-graph Graphviz Generator

You can use +yard-graph+ to generate dot graphs of your code. This, of course,
requires Graphviz ( and the +dot+ binary. By default
this will generate a graph of the classes and modules in the best UML2 notation
that Graphviz can support, but without any methods listed. With the <tt>--full</tt>
option, methods and attributes will be listed. There is also a <tt>--dependencies</tt>
option to show mixin inclusions. You can output to stdout or a file, or pipe directly
to +dot+. The same public, protected and private visibility rules apply to yard-graph.
More options can be seen by typing <tt>yard-graph --help</tt>, but here is an example:

  > yard-graph --protected --full --dependencies


- <b>Jun.16.08</b>: 0.2.2 release. This is the largest changset since yard's 
  conception and involves a complete overhaul of the parser and API to make it
  more robust and far easier to extend and use for the developer.

- <b>Feb.20.08</b>: 0.2.1 release. 

- <b>Feb.24.07</b>: Released 0.1a experimental version for testing. The goal here is
  to get people testing YARD on their code because there are too many possible  
  code styles to fit into a sane amount of test cases. It also demonstrates the 
  power of YARD and what to expect from the syntax (Yardoc style meta tags).    

== COPYRIGHT                                                                    

YARD was created in 2007-2008 by Loren Segal (lsegal -AT- soen -DOT- ca) and is    
licensed under the MIT license. Please see the LICENSE.txt for more information.
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