Interface Taglet

public interface Taglet
The interface for a custom taglet supported by doclets such as the standard doclet. Custom taglets are used to handle custom tags in documentation comments; custom tags can be instantiated individually as either block tags, which appear at the end of a comment, or inline tags, which can appear within the main body of a documentation comment.

Each implementation of a taglet must provide a public no-argument constructor to be used by doclets to instantiate the taglet. A doclet will interact with classes implementing this interface as follows:

  1. The doclet will create an instance of a taglet using the no-arg constructor of the taglet class.
  2. Next, the doclet calls the init method with an appropriate environment and doclet.
  3. Afterwards, the doclet calls getName, getAllowedLocations, and isInlineTag, to determine the characteristics of the tags supported by the taglet.
  4. As appropriate, the doclet calls the toString method on the taglet object, giving it a list of tags, the element whose documentation comment contains the tags, and the root URI of the generated output, from which the taglet can determine the string to be included in the documentation. The doclet will typically specify any requirements on the contents of the string that is returned.

If a taglet object is created and used without the above protocol being followed, then the taglet's behavior is not defined by this interface specification.

API Note:
It is typical for a taglet to be designed to work in conjunction with a specific doclet.
Since:
9
See Also:

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static enum 
    Taglet.Location
    The kind of location in which a tag may be used.

  • Method Summary

    Modifier and Type
    Method
    Description
    Set<Taglet.Location>
    getAllowedLocations()
    Returns the set of supported locations for block tags.
    String
    getName()
    Returns the name of the tag supported by this taglet.
    default void
    init(DocletEnvironment env, Doclet doclet)
    Initializes this taglet with the given doclet environment and doclet.
    default boolean
    isBlockTag()
    Indicates whether this taglet supports block tags.
    boolean
    isInlineTag()
    Indicates whether this taglet supports inline tags.
    String
    toString(List<? extends DocTree> tags, Element element)
    Returns the string representation of the specified instances of this tag to be included in the generated output.
    default String
    toString(List<? extends DocTree> tags, Element element, URI docRoot)
    Returns the string representation of the specified instances of this tag to be included in the generated output.

  • Method Details

    • getAllowedLocations

      Set<Taglet.Location> getAllowedLocations()
      Returns the set of supported locations for block tags.
      Returns:
      the set of supported locations for block tags

    • isInlineTag

      boolean isInlineTag()
      Indicates whether this taglet supports inline tags.
      Returns:
      true if this taglet supports inline tags

    • isBlockTag

      default boolean isBlockTag()
      Indicates whether this taglet supports block tags.
      Implementation Requirements:
      This implementation returns the inverse result to isInlineTag.
      Returns:
      true if this taglet supports block tags
      Since:
      15

    • getName

      String getName()
      Returns the name of the tag supported by this taglet.
      Returns:
      the name of this tag

    • init

      default void init(DocletEnvironment env, Doclet doclet)
      Initializes this taglet with the given doclet environment and doclet.
      API Note:
      The environment may be used to access utility classes for elements and types if needed.
      Implementation Requirements:
      This implementation does nothing.
      Parameters:
      env - the environment in which the doclet and taglet are running
      doclet - the doclet that instantiated this taglet

    • toString

      String toString(List<? extends DocTree> tags, Element element)
      Returns the string representation of the specified instances of this tag to be included in the generated output.

      If this taglet supports inline tags, this method will be called once per instance of the inline tag, each time with a singleton list. If this taglet supports block tags, it will be called once for each comment containing instances of block tags, with a list of all the instances of the block tag in that comment.

      API Note:
      Taglets that do not need the root URI of the generated output may implement this method only. Taglets that require the root URI to link to other doclet-generated resources should override toString(List, Element, URI), and optionally throw an exception in the implementation of this method.
      Parameters:
      tags - the list of instances of this tag
      element - the element to which the enclosing comment belongs
      Returns:
      the string representation of the tags to be included in the generated output
      Throws:
      UnsupportedOperationException - if toString(List, Element, URI) should be invoked instead
      See Also:

    • toString

      default String toString(List<? extends DocTree> tags, Element element, URI docRoot)
      Returns the string representation of the specified instances of this tag to be included in the generated output.

      If this taglet supports inline tags, this method will be called once per instance of the inline tag, each time with a singleton list. If this taglet supports block tags, it will be called once for each comment containing instances of block tags, with a list of all the instances of the block tag in that comment.

      The docRoot argument identifies the root of the generated output as seen by the current resource, and may be used to resolve links to other resources generated by the doclet.

      API Note:
      The exact form of docRoot is doclet-specific. For the standard doclet, it is a relative URI from the current resource to the root directory of the generated output. Taglets intended for use with other doclets should check the validity of the docRoot argument as appropriate.
      Implementation Requirements:
      The default implementation invokes toString(tags, element).
      Parameters:
      tags - the list of instances of this tag
      element - the element to which the enclosing comment belongs
      docRoot - the root URI of the generated output
      Returns:
      the string representation of the tags to be included in the generated output
      Throws:
      IllegalArgumentException - if docRoot is not a valid URI
      Since:
      27
      See Also: