yWorks UML Doclet 3.1 User's Guide

Contents

1. Introduction
2. System Requirements
3. Installing yDoc
4. Running yDoc
   • Using the yDoc doclet
   • Using the yDoc doclet from within a Java IDE
   • yDoc Quick Start
5. yDoc Features
   • Generating UML class diagrams
   • General Layout of UML class diagrams
   • Using filters
   • Using the XML driven taglet factory
   • Custom command line options
6. Configuring yDoc
   • resources/ydoc.cfg
   • UML Styles
7. Limitations
8. Acknowledgments
   • Apache Software License
   • GNU Lesser General Public License

1. Introduction

Welcome to the yWorks UML Doclet User's Guide.
This guide explains how to use yWorks UML Doclet or yDoc for short, a javadoc extension (more specifically a doclet/taglet bundle) that provides

• functionality to auto-generate, customize, and include UML diagrams in the API documentation of your Java products
• a filter interface which allows for custom suppression of class, field, or method documentation
• an easy to use mechanism for defining simple custom tags via XML

Although, yDoc is designed in such a way that it allows user's to continue using all the features they know from standard javadoc, some basic knowledge about javadoc usage in general and doclet usage specifically is required to successfully use yDoc.

Detailed information on javadoc is available at https://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/index.html.
Detailed information on doclets is available at https://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/doclet/overview.html.

2. System Requirements

yDoc 3.1 requires JDK 1.8 installed on your system.
To view UML class diagrams in SVG or SVGZ format, you need a browser with native SVG support. To view UML class diagrams in SWF format, you need a browser with a Flash Player plug-in. Flash Player plug-ins are available from Adobe.
If you want to run yDoc under Unix/Linux operating systems, you need to have an X server installed and running, since yDoc makes use of the java awt and/or swing packages (for UML generation only).

3. Installing yDoc

Unzip the yDoc archive (yworks-uml-doclet-3.1-jdk1.8.zip) into a directory of your choice. It will create a lib/, a doc/, and a resources/ subdirectory.
The lib directory contains the java classes you need to run the ydoc expansion as jar libraries.
The doc directory contains the yDoc User's Guide in HTML and PDF format, the DocFilter and PathResolver API Documentation in HTML format, and several usage samples.
The resources directory contains various configuration files which you can use to customize the behaviour of the yDoc expansion. See Configuring yDoc and Using the XML driven taglet factory for more details.

4. Running yDoc

Basically you run javadoc. The only difference is, that you tell javadoc to use the facilities provided by yDoc as a plug-in.
Read on for detailed information on how to do that. You can skip this part, if you are already familiar with using custom doclets for javadoc.

Using the yDoc doclet

We recommend running javadoc either using a build tool such as ANT (version 1.5.2 or better) or directly from commandline. Before running javadoc from commandline, put your commandline options into a file called "options" and run javadoc by invoking
    javadoc @options @packages
where "packages" is the filename of a file containing the java packages you want to be documented.

See yDoc Quick Start for simple examples on how to use yDoc.

For detailed documentation on the javadoc options, see the javadoc tool homepage at https://docs.oracle.com/javase/8/docs/technotes/guides/javadoc/index.html.

To use the yDoc expansion the following options are especially important:

• -docletpath docletpathlist
  This option tells javadoc where to look for the yDoc expansion.
  The docletpathlist must contain the path to the library ydoc.jar
       <ydoc_install_dir>/lib/ydoc.jar
  and the resources directory
       <ydoc_install_dir>/resources
  Important:
  If you want to use the yDoc UML generation, docletpathlist must also contain the path to your compiled, unobfuscated Java class files (*.class), for which you want to generate the API documentation, and to all libraries needed to compile your Java source files.
• -doclet ydoc.doclets.YStandard
  The -doclet ydoc.doclets.YStandard option finally tells javadoc to actually use the YStandard doclet, which is the core class of the ydoc expansion.

See yDoc Features for information on (custom) commandline options and on how to use the specific capabilites of yDoc.

A sample options file on a Win32 operating system could look like this:

  -d <destination directory>
  -sourcepath <source directory>
  -breakiterator
  -generic
  -umlautogen
  -author
  -docletpath <YID>/lib/ydoc.jar;<YID>/resources;<some path>/myapp.jar
  -doclet ydoc.doclets.YStandard
  -filterpath <YID>/lib/ydoc.jar
  -filter ydoc.filters.ExcludeFilter
  -tagletpath <YID>/lib/ydoc.jar
  -tag param
  -tag return
  -tag see
  -ytag y.uml
            

where <YID> denotes the <ydoc_install_dir>.
On Unix/Linux operating systems, you will have to use " : " as a path separator instead of " ; ".

Using the yDoc doclet from within a Java IDE

Running yDoc from within Eclipse 3

Running yDoc from within IntelliJ Idea 6

Running yDoc from within Netbeans 5.5

yDoc Quick Start

This section demonstrates how to use yDoc to generate a Javadoc page of a sample class that will automatically include an UML diagram depicting that class.

• yDoc from commandline

  Look in <YID>/doc/examples for sample options files and sample Java sources to test yDoc.
  All you need to do is invoking javadoc in <ydoc_install_dir> with either
       javadoc @doc/examples/options.sample.linux
  or
       javadoc @doc/examples/options.sample.win32
  depending on your operating system.

• yDoc in ANT

  Using ANT 1.5.2 or better, you can use ANT's javadoc task to run yDoc.

  Look in <YID>/doc/examples for a sample ANT build file and sample Java sources to test yDoc.
  All you need to do is invoking ant in <ydoc_install_dir> with
       ant -buildfile doc/examples/build-sample.xml test-ydoc

The generated API pages can now be found in <ydoc_install_dir>/doc/api/examples.

Note that the generated UML diagrams are in PNG format. If you want to generate the uml diagrams in a different format (SVG, SVGZ, SWF, GIF, JPG) simply change the value of formats.fileformat in the yDoc configuration file <ydoc_install_dir>/resources/ydoc.cfg accordingly.

The next tutorial step would be to look in <ydoc_install_dir>/doc/examples for the sample option/build files and sample Java sources which have been used in this example. Once you understand the options and tags, you are ready to use yDoc in your own project.

5. yDoc Features

Generating UML class diagrams

yDoc will generate UML diagrams, if one or more of the following commandline options are used:

• -umlgen
• -umltypegen
• -umlpackagegen
• -umloverviewgen
• -umlautogen

All UML diagrams feature hyperlinks for the displayed packages, types, and type members, which allow direct access to the corresponding documentation.

See Custom command line options for additional details.

yDoc supports several output formats for UML diagrams, including SVG, SWF, and PNG and will automatically integrate the diagrams into the generated HTML API documentation.
Moreover, yDoc provides many settings which allow to customize the generated UML diagrams in great detail.

See Configuring yDoc for details.

Important:
yDoc uses the Java Reflection API to generate the class diagrams, therefore you need to specify the path to your compiled, unobfuscated Java class files (*.class) and to all libraries needed to compile your Java source files in the -docletpath option. Your class files may be located in a jar file.

Alternatively, yDoc can embed predefined diagrams instead of generating them. Predefined diagrams have to be available in GraphML. GraphML is a generic graph interchange file format. Diagrams in this format can, e.g., be created using yEd, yWorks' free graph editor.

For yDoc to be able to find and read such diagrams, a diagram locator has to be specified.

The distribution comes with one predefined diagram locator. For this default locator to work successfully, predefined diagram files have to meet the following criteria:

• Overview diagrams must be in the same directory as your overview.html. The diagram files have to be named overview<id>.graphml, where <id> denotes the diagram ID (see also Configuring yDoc).
• Package diagrams must be in the same directory as your package.html. The diagram files have to be named package<id>.graphml, where <id> denotes the diagram ID (see also Configuring yDoc).
• Type diagrams must be in the same directory as the corresponding source file. The diagram files have to follow the same naming convention as the Java source file except for the .graphml file extension.

To use this default diagram locator, you need to specify the following two commandline options:
    -diagramlocatorpath <ydoc_install_dir>/lib/ydoc.jar
    -diagramlocator ydoc.resolvers.DefaultDiagramLocator

To create and use your own diagram locators, all you have to do is implementing the ydoc.resolvers.PathResolver interface and register the locator similar to the above example. The mechanism to register locators works similar to the one used for doclets.

PathResolver API

Documentation for the ydoc.resolvers.PathResolver interface, which comprises the PathResolver API.

General Layout of UML class diagrams

	Associations structural relationships between a whole and its parts, i.e. has a or instantiates Every declared field constitutes an association.
	Dependencies semantic relationships in which a change to one thing may effect the semantics of the other thing There are several heuristics as to what constitues a dependency. See Configuring yDoc.
	Generalizations specialization/generalization relationships, i.e. is a or subclass/superclass For interfaces there may be more than one generalization relationship.
	Realizations semantic relationships between classifiers, i.e. interface/implementing class For interfaces there are no realization relationships.

Using filters

yDoc provides a sophisticated filter framework, which lets you exclude parts of your API from documentation using customizable filter criteria.

The distribution comes with one predefined filter, which lets you exclude classes/interfaces, fields, and/or methods from documentation, if their documentation comment contains an @y.exclude tag.
To use this filter, you need to specify the following two commandline options:
    -filterpath <ydoc_install_dir>/lib/ydoc.jar
    -filter ydoc.filters.ExcludeFilter

To create and use your own filters, all you have to do is implement the ydoc.filters.DocFilter interface and register the filter similar to the above example. The mechanism to register filters works similar to the one used for doclets.

DocFilter API

Documentation for the ydoc.filters.DocFilter interface, which comprises the DocFilter API.

Using the XML driven taglet factory

By specifying the -generic option, you can tell yDoc to register simple taglets, which are more powerful than the ones created by the standard -tag option and are defined in the resources/taglet_definitions.xml and resources/taglet_templates.xml files.
By adding more definitions to those files, you can use/register more simple taglets.

The basic idea is to have template definitions that define taglet behaviour and taglet definitions that define scope, name, and which template to use.

For examples on how to define taglets, see the two mentioned xml files.

Taglet Definitions

The following XML elements are used to define taglets:

• <taglet>
  Each of these elements results in the registration of one particular taglet.
  The value of the name attribute specifies the javadoc tag for the taglet. The value of the attribute allowMultipleTags specifies if more than one appearance of the javadoc tag per doc element is allowed. If not, all but the first tag will be ignored.
• <usage>
  Required element that specifies the taglet scope as per the taglet API.
• <headline>
  Required root element for <singular> and <plural>.
• <singular>
  Required element that specifies the headline for the tag comment if only one javadoc tag or no <plural> element is present.
• <plural>
  Optional element that specifies the headline for the tag comment if multiple javadoc tags are allowed and present.

In general, it is a good idea to use at least one '.' character in the name of custom tags to avoid potential conflicts/overrides.

Template Definitions

The following XML elements are used to define templates:

• <template>
  Each of these elements results in the creation of one particular template.
  The value of the name attribute has to be unique among all templates. It is used to reference the template in the taglet definition.
• <headline>
  Required element that specifies the HTML code for the headline of the tag comment.
  You may specify one parameter sign, i.e. #0.
  You may use a single parameter multiple times, e.g. <headline> <![CDATA[bla #0 bla#0bla]]> </headline>
  The element should contain unparsed character data, i.e. <![CDATA[....]]>
• <content>
  Required element that specifies the HTML formatting for the tag comment.
  The value of the separator attribute specifies if and how to break down the comment into parameters.
  Possible values are:

  -	any single character		breaks the comment at each occurrence of the specified character
  -	the token "first-whitespace"		breaks the comment at the first occurrence of a whitespace
  -	the token "first-word-or-tag"		breaks the comment at the first occurrence of a whitespace that does not belong to an inline tag
  -	the token "whitespace"		breaks the comment at each occurrence of a whitespace
  -	the token "none" (default)		results in one token only, namely the whole comment

• <content-item>
  Required element that specifies the HTML code to wrap the tag comment in. If multiple javadoc tag are present for a particular doc element, then one content item is created for each tag comment.
  You may specify up to ten parameter signs, i.e. #x, where -1 < x < 10.
  You may use a single parameter multiple times.
  The element should contain unparsed character data.
• <content-sep>
  Optional element that defaults to "".
  Its value will be inserted between content items.
  The element should contain unparsed character data.
• <content-start>
  Optional element that defaults to "".
  Its value will be inserted directly after the headline, before the first content item.
  The element should contain unparsed character data.
• <content-end>
  Optional element that defaults to "".
  Its value will be inserted directly after the the last content item.
  The element should contain unparsed character data.

In general, it is a good idea to use the <DT> tag for headlines and the <DD> tag for content, since all output generated by javadoc taglets appears in definition lists.

Custom command line options

yDoc provides several custom command line options:

• -diagramlocator class
  Specifies the class file for the diagram locator to be used. Use the fully-qualified name for class. Use the -diagramlocatorpath option to specify the path to the diagram locator.
• -diagramlocatorpath -diagramlocatorpathlist
  Specifies the search paths for finding diagram locator class files (*.class). The diagramlocatorpathlist can contain multiple paths separated by the system-dependant path-separator.
• -filter class
  Specifies the class file for the filter to be applied. Use the fully-qualified name for class. Use the -filterpath option to specify the path to the filter.
• -filterpath filterpathlist
  Specifies the search paths for finding filter class files (*.class). The filterpathlist can contain multiple paths separated by the system-dependant path-separator.
• -generic
  The taglet definitions in resources/taglet_definitions.xml and resources/taglet_templates.xml are used to create and register simple taglets.
• -license file
  Specifies the path to the license file.
• -resourcepath resourcepathlist
  Specifies the search paths for finding resource files (i.e. taglet definition files, ydoc configuration file, ydoc license file). The resourcepathlist can contain multiple paths separated by the system-dependant path-separator.
• -umlautogen
  Same as using -umltypegen, -umlpackagegen, and -umloverviewgen in combination
• -umlfileformat formatname
  Overrides the uml_file_format property in resources/ydoc.cfg
  See the section about UML file formats for a list of supported formats.
• -umlgen
  UML diagrams will be created and embedded for all documented files with an @y.uml tag.
  @y.uml may be used in type, package, and overview documentation.
• -umloverviewgen
  An UML overview diagram will be created and embedded, even if there is no @y.uml tag in overview.html.
• -umlpackagegen
  UML diagrams will be created and embedded for all documented packages, not only for those with an @y.uml tag.
• -umltypegen
  UML diagrams will be created and embedded for all documented classes and interfaces, not only for those with an @y.uml tag.
• -ytag
  Allows to specify the position of custom yDoc tags (i.e. @y.uml or tags defined via the taglet factory) in relation to standard tags.

6. Configuring yDoc

resources/ydoc.cfg

resources/ydoc.cfg is yDoc's main configuration file.
It uses a simple XML format consisting of nested group and property elements.

Following is the complete list of recognized group and property declarations.

UML Styles

A style set defines the visual features of UML diagrams and is specified in a XML file which conforms to the yDoc style definition schema.
The yDoc distribution comes with several predefined style files, see resources/styles.
You can customize colors (main, border, text), fonts, shapes, and lines by either modifying an existing style file or creating a new one.
The yDoc 3.1 distribution includes StyleEd, a GUI-based style editor, that greatly simplifies customization. The editor is written completely in Java and will run on any Java 1.8 (or higher) runtime environment. All files needed to run StyleEd are contained in the executable JAR file lib/styleed.jar, i.e. double-clicking the file or invoking
java -jar <YID>/lib/styleed.jar
will start StyleEd.
Aside from style file editing, StyleEd also allows users to experiment with layout settings for the various diagram types.

7. Limitations

• The yDoc Evaluation version will only document ten classes.
  If one or more of those are excluded from documentation via the @y.exclude tag, they still count against that limit.
• In UML class diagrams generated by the yDoc Evaluation version, the associations list and the dependencies list will only display the ten above mentioned classes.

8. Acknowledgments

This product includes software developed by the Apache Software Foundation (http://www.apache.org/).
yDoc uses Batik to generate SVG files. Batik is distributed under the Apache Software License, Version 2.0.

yDoc uses FreeHEP VectorGraphics to generate SWF files. The FreeHEP VectorGraphics class library is distributed under the GNU Lesser General Public License.

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