commit	4f4b86b873b7676979d3258030fdfc382e22a06b	[log] [tgz]
author	Simon Ogorodnik <Simon.Ogorodnik@jetbrains.com>	Tue May 16 20:44:28 2017 +0300
committer	Simon Ogorodnik <Simon.Ogorodnik@jetbrains.com>	Thu May 18 16:02:54 2017 +0300
tree	a727921e4a63277513a108d2263e4604eacb09a1
parent	f7f3eff54af925b307e3dbbf8eb8d731a0ba30b9 [diff]

tree: a727921e4a63277513a108d2263e4604eacb09a1

README.md

dokka

Dokka is a documentation engine for Kotlin, performing the same function as javadoc for Java. Just like Kotlin itself, Dokka fully supports mixed-language Java/Kotlin projects. It understands standard Javadoc comments in Java files and KDoc comments in Kotlin files, and can generate documentation in multiple formats including standard Javadoc, HTML and Markdown.

Using Dokka

Using the Gradle plugin

buildscript {
    repositories {
        jcenter()
    }

    dependencies {
        classpath "org.jetbrains.dokka:dokka-gradle-plugin:${dokka_version}"
    }
}

apply plugin: 'org.jetbrains.dokka'

The plugin adds a task named "dokka" to the project.

Minimal dokka configuration:

dokka {
    outputFormat = 'html' 
    outputDirectory = "$buildDir/javadoc"
}

Output formats

The available configuration options are shown below:

dokka {
    moduleName = 'data'
    outputFormat = 'html'
    outputDirectory = "$buildDir/javadoc"
    processConfigurations = ['compile', 'extra']
    includes = ['packages.md', 'extra.md']
    samples = ['samples/basic.kt', 'samples/advanced.kt']
    
    jdkVersion = 6 // Used for linking to JDK
    
    skipDeprecated = false // Do not output deprecated members, applies globally, can be overridden by packageOptions
    reportNotDocumented = true // Emit warnings about not documented members, applies globally, also can be overridden by packageOptions
    
    skipEmptyPackages = true // Do not create index pages for empty packages
 
    impliedPlatforms = ["JVM"] // See platforms section of documentation 
    
    // Selector for resolving dokkaFatJar or File for local path to dokka-fatjar
    dokkaFatJar = "org.jetbrains.dokka:dokka-fatjar:$dokka_version"
    
    // By default, sourceRoots is taken from processConfigurations
    // Short form sourceRoots
    // If specified, processConfigurations are ignored
    sourceDirs = files('src/main/kotlin')
    
    // By default, sourceRoots is taken from processConfigurations
    // Full form sourceRoot declaration
    // If specified, processConfigurations are NOT ignored, and sourceRoots are appended
    // Repeat for multiple sourceRoots
    sourceRoot {
        // Path to source root
        path = "src" 
        // See platforms section of documentation 
        platforms = ["JVM"] 
    }
    
    // Mapping to source
    // Repeat for multiple mappings
    linkMapping {
        dir = "src/main/kotlin"
        url = "https://github.com/cy6erGn0m/vertx3-lang-kotlin/blob/master/src/main/kotlin"
        suffix = "#L"
    }
    
    // No default documentation link to kotlin-stdlib
    noStdlibLink = false
    
    // Repeat for multiple links
    externalDocumentationLink {
        url = new URL("https://example.com/docs")
        // If package-list file located in non-standard location
        // packageListUrl = new URL("file:///home/user/localdocs/package-list") 
    }
    
    // Repeat for multiple packageOptions
    packageOptions {
        prefix = "kotlin" // will match kotlin and all sub-packages of it
        // All options are optional, default values are below:
        skipDeprecated = false
        reportUndocumented = true // Emit warnings about not documented members 
        includeNonPublic = false
    }
}

To get it generated use gradle dokka task

./gradlew dokka

More dokka tasks can be added to a project like this:

task dokkaJavadoc(type: org.jetbrains.dokka.gradle.DokkaTask) {
    outputFormat = 'javadoc'
    outputDirectory = "$buildDir/javadoc"
}

Please see the Dokka Gradle example project for an example.

Android

If you are using Android there is a separate gradle plugin. Just make sure you apply the plugin after com.android.library and kotlin-android.

buildscript {
    repositories {
        jcenter()
    }

    dependencies {
        classpath "org.jetbrains.dokka:dokka-android-gradle-plugin:${dokka_version}"
    }
}

apply plugin: 'com.android.library'
apply plugin: 'kotlin-android'
apply plugin: 'org.jetbrains.dokka-android'

Using the Maven plugin

The Maven plugin is available in JCenter. You need to add the JCenter repository to the list of plugin repositories if it's not there:

<pluginRepositories>
    <pluginRepository>
        <id>jcenter</id>
        <name>JCenter</name>
        <url>https://jcenter.bintray.com/</url>
    </pluginRepository>
</pluginRepositories>

Minimal maven configuration is

<plugin>
    <groupId>org.jetbrains.dokka</groupId>
    <artifactId>dokka-maven-plugin</artifactId>
    <version>${dokka.version}</version>
    <executions>
        <execution>
            <phase>pre-site</phase>
            <goals>
                <goal>dokka</goal>
            </goals>
        </execution>
    </executions>
</plugin>

By default files will be generated in target/dokka.

The following goals are provided by the plugin:

dokka:dokka - generate HTML documentation in Dokka format (showing declarations in Kotlin syntax);
dokka:javadoc - generate HTML documentation in JavaDoc format (showing declarations in Java syntax);
dokka:javadocJar - generate a .jar file with JavaDoc format documentation.

The available configuration options are shown below:

<plugin>
    <groupId>org.jetbrains.dokka</groupId>
    <artifactId>dokka-maven-plugin</artifactId>
    <version>${dokka.version}</version>
    <executions>
        <execution>
            <phase>pre-site</phase>
            <goals>
                <goal>dokka</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
    
        <!-- Set to true to skip dokka task, default: false -->
        <skip>false</skip>
    
        <!-- Default: ${project.artifactId} -->
        <moduleName>data</moduleName>
        <!-- See list of possible formats below -->
        <outFormat>html</outFormat>
        <!-- Default: ${project.basedir}/target/dokka -->
        <outputDir>some/out/dir</outputDir>
        
        <!-- List of '.md' files with perPackage and module docs -->
        <includes>
            <file>packages.md</file>
            <file>extra.md</file>
        </includes>
        
        <!-- List of sample roots -->
        <samplesDirs>
            <dir>src/test/samples</dir>
        </samplesDirs>
        
        <!-- Used for linking to JDK, default: 6 -->
        <jdkVersion>6</jdkVersion>
        
        <!-- Do not output deprecated members, applies globally, can be overridden by packageOptions -->
        <skipDeprecated>false</skipDeprecated> 
        <!-- Emit warnings about not documented members, applies globally, also can be overridden by packageOptions -->
        <reportNotDocumented>true</reportNotDocumented>             
        <!-- Do not create index pages for empty packages -->
        <skipEmptyPackages>true</skipEmptyPackages> 
        
        <!-- See platforms section of documentation -->
        <impliedPlatforms>
            <platform>JVM</platform>
        </impliedPlatforms>
        
        <!-- Short form list of sourceRoots, by default, set to ${project.compileSourceRoots} -->
        <sourceDirectories>
            <dir>src/main/kotlin</dir>
        </sourceDirectories>
        
        <!-- Full form list of sourceRoots -->
        <sourceRoots>
            <root>
                <path>src/main/kotlin</path>
                <!-- See platforms section of documentation -->
                <platforms>JVM</platforms>
            </root>
        </sourceRoots>
        
        <sourceLinks>
            <link>
                <dir>${project.basedir}/src/main/kotlin</dir>
                <url>http://github.com/me/myrepo</url>
                <!-- Line suffix, e.g #L -> /me/myrepo/some.html#L99 -->
                <urlSuffix>#L</urlSuffix>
            </link>
        </sourceLinks>
        
        <!-- No default documentation link to kotlin-stdlib -->
        <noStdlibLink>false</noStdlibLink>
        
        <externalDocumentationLinks>
            <link>
                <url>https://example.com/docs</url>
                <!-- If package-list file located in non-standard location -->
                <!-- <packageListUrl>file:///home/user/localdocs/package-list</packageListUrl> -->
            </link>
        </externalDocumentationLinks>

        <perPackageOptions>
            <packageOptions>
                <!-- Will match kotlin and all sub-packages of it -->
                <prefix>kotlin</prefix>
                
                <!-- All options are optional, default values are below: -->
                <skipDeprecated>false</skipDeprecated>
                <!-- Emit warnings about not documented members  -->
                <reportUndocumented>true</reportUndocumented>
                <includeNonPublic>false</includeNonPublic>
            </packageOptions>
        </perPackageOptions>
    </configuration>
</plugin>

Please see the Dokka Maven example project for an example.

Output formats

Using the Ant task

The Ant task definition is also contained in the dokka-fatjar.jar referenced above. Here's an example of using it:

<project name="Dokka" default="document">
    <typedef resource="dokka-antlib.xml" classpath="dokka-fatjar.jar"/>

    <target name="document">
        <dokka src="src" outputdir="doc" modulename="myproject"/>
    </target>
</project>

The Ant task supports the following attributes:

outputDir - the output directory where the documentation is generated
outputFormat - the output format (see the list of supported formats above)
classpath - list of directories or .jar files to include in the classpath (used for resolving references)
samples - list of directories containing sample code (documentation for those directories is not generated but declarations from them can be referenced using the @sample tag)
moduleName - the name of the module being documented (used as the root directory of the generated documentation)
include - names of files containing the documentation for the module and individual packages
skipDeprecated - if set, deprecated elements are not included in the generated documentation
jdkVersion - version for linking to JDK
impliedPlatforms - See platforms section
<sourceRoot path="src" platforms="JVM" /> - analogue of src, but allows to specify platforms
<packageOptions prefix="kotlin" includeNonPublic="false" reportUndocumented="true" skipDeprecated="false"/> - Per package options for package kotlin and sub-packages of it
noStdlibLink - No default documentation link to kotlin-stdlib
<externalDocumentationLink url="https://example.com/docs" packageListUrl="file:///home/user/localdocs/package-list"/> - linking to external documentation, packageListUrl should be used if package-list located not in standard location

Using the Command Line

To run Dokka from the command line, download the Dokka jar. To generate documentation, run the following command:

java -jar dokka-fatjar.jar <source directories> <arguments>

Dokka supports the following command line arguments:

-output - the output directory where the documentation is generated
-format - the output format:
- html - HTML (default)
- markdown - Markdown
- gfm - GitHub-Flavored Markdown
- jekyll - Markdown adapted for Jekyll sites
- javadoc - Javadoc (showing how the project can be accessed from Java)
-classpath - list of directories or .jar files to include in the classpath (used for resolving references)
-samples - list of directories containing sample code (documentation for those directories is not generated but declarations from them can be referenced using the @sample tag)
-module - the name of the module being documented (used as the root directory of the generated documentation)
-include - names of files containing the documentation for the module and individual packages
-nodeprecated - if set, deprecated elements are not included in the generated documentation
-impliedPlatforms - List of implied platforms (comma-separated)
-packageOptions - List of package options in format prefix,-deprecated,-privateApi,+warnUndocumented;...
-links - External documentation links in format url^packageListUrl^^url2...
-noStdlibLink - Disable documentation link to stdlib

Output formats

html - minimalistic html format used by default
javadoc - Dokka mimic to javadoc
html-as-java - as html but using java syntax
markdown - Markdown structured as html
- gfm - GitHub flavored markdown
- jekyll - Jekyll compatible markdown
kotlin-website* - internal format used for documentation on kotlinlang.org

Platforms

Dokka can annotate elements with special platform block with platform requirements

Example of usage can be found on kotlinlang.org

Each source root has list of platforms for which members are suitable. Also, the list of 'implied' platforms is passed to Dokka, if member suitable for all platforms from implied platform set, then only platforms which not contained in the set will be shown.

Dokka Internals

Documentation Model

Dokka uses Kotlin-as-a-service technology to build code model, then processes it into documentation model. Documentation model is graph of items describing code elements such as classes, packages, functions, etc.

Each node has semantic attached, e.g. Value:name -> Type:String means that some value name is of type String.

Each reference between nodes also has semantic attached, and there are three of them:

Member - reference means that target is member of the source, form tree.
Detail - reference means that target describes source in more details, form tree.
Link - any link to any other node, free form.

Member & Detail has reverse Owner reference, while Link's back reference is also Link.

Nodes that are Details of other nodes cannot have Members.

Rendering Docs

When we have documentation model, we can render docs in various formats, languages and layouts. We have some core services:

FormatService -- represents output format
LocationService -- represents folder and file layout
SignatureGenerator -- represents target language by generating class/function/package signatures from model

Basically, given the documentation as a model, we do this:

    val signatureGenerator = KotlinSignatureGenerator()
    val locationService = FoldersLocationService(arguments.outputDir)
    val markdown = JekyllFormatService(locationService, signatureGenerator)
    val generator = FileGenerator(signatureGenerator, locationService, markdown)
    generator.generate(documentation)

Building Dokka

Dokka is built with Gradle. To build it, use ./gradlew build. Alternatively, open the project directory in IntelliJ IDEA and use the IDE to build and run Dokka.