= YARD Release 0.2.2 (June 16th 2008) Copyright 2007-2008 Loren Segal == SYNOPSIS YARD is a documentation generation tool for the Ruby programming language (http://www.ruby-lang.org). 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. == FEATURE LIST 1. RDoc/SimpleMarkup Formatting Compatibility: 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. Yardoc Meta-tag Formatting Like Python, Java, Objective-C and other languages: 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: Table 1. Meta-tags and their descriptions @param [Types] name description:: Description Allows for the definition of a method parameter with optional type information. @yieldparam [Types] name description:: Description Allows for the definition of a method parameter to a yield block with optional type information. @yield description:: Allows the developer to document the purpose of a yield block in a method. @return [Types] description:: Describes what the method returns with optional type information. @deprecated description:: 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. @raise class description:: Tells the developer that the method may raise an exception and of what type. @see name:: References another object, URL, or other for extra information. @since number:: Lists the version number in which the object first appeared. @version number:: Lists the current version of the documentation for the object. @author name:: 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 = contents.read if respond_to? :read contents.reverse end 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 descriptive. 3. Custom Constructs and Extensibility of YARD: Take for instance the example: class A class << self def define_name(name, value) class_eval "def #{name}; #{value.inspect} end" end end # Documentation string for this name define_name :publisher, "O'Reilly" end 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. Raw Data Output: 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 yardoc --help 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 --use-cache (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 --protected or --private 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+: YARD::Rake::YardocTask.new do |t| t.files = ['lib/**/*.rb', OTHER_PATHS] # optional t.options = ['--any', '--extra', '--opts'] # optional end both the +files+ and +options+ settings are optional. +files+ will default to lib/**/*.rb and +options+ will represents any options you might want to add. Again, a full list of options is available by typing yardoc --help 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 (http://www.graphviz.org) 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 --full option, methods and attributes will be listed. There is also a --dependencies 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 yard-graph --help, but here is an example: > yard-graph --protected --full --dependencies == CHANGELOG - Jun.16.08: 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. - Feb.20.08: 0.2.1 release. - Feb.24.07: 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.