<?xml version="1.0" encoding="UTF-8"?>

<!--
 ! Licensed to the Apache Software Foundation (ASF) under one or more
 ! contributor license agreements.  See the NOTICE file distributed with
 ! this work for additional information regarding copyright ownership.
 ! The ASF licenses this file to You under the Apache License, Version 2.0
 ! (the "License"); you may not use this file except in compliance with
 ! the License.  You may obtain a copy of the License at
 !
 !     http://www.apache.org/licenses/LICENSE-2.0
 !
 ! Unless required by applicable law or agreed to in writing, software
 ! distributed under the License is distributed on an "AS IS" BASIS,
 ! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ! See the License for the specific language governing permissions and
 ! limitations under the License.
 !
 !
 !  Document   : plugin.dtd
 !  Created on : 14 avril 2006, 22:14
 !  Author     : Chris Mattmann, Jerome Charron
 !  Description: Nutch plug-in manifest DTD
 !
 !  PUBLIC ID  : -//Apache Software Fundation//DTD Nutch Plugin Manifest 1.0//EN
 !  SYSTEM ID  : http://lucene.apache.org/nutch/plugin.dtd
-->


<!--
 ! The <plugin> element defines the body of the manifest.
 ! It optionally contains definitions for the plug-in runtime,
 ! definitions of other plug-ins required by this one,
 ! declarations of any new extension points being introduced by the plug-in,
 ! as well as configuration of functional extensions
 ! (configured into extension points defined by other plug-ins,
 ! or introduced by this plug-in).
 !-->
<!ELEMENT plugin (runtime?, requires?, extension-point*, extension*)>

<!-- A user displayable name for the plug-in -->
<!ATTLIST plugin name CDATA #REQUIRED>

<!-- 
 ! A unique identifier for the plug-in.
 ! To minimize potential for naming collisions,
 ! the identifier should be derived from the internet domain id
 ! of the supplying provider (reversing the domain name tokens and
 ! appending additional name tokens separated by dot [.]).
 ! For example, provider nutch.org could define plug-in identifier
 ! org.nutch.myplugin
 !-->
<!ATTLIST plugin id CDATA #REQUIRED>

<!--
 ! The plug-in version number.
 ! NOTE : Version numbers compatibility are not yet implemented.
 !-->
<!ATTLIST plugin version CDATA #REQUIRED>

<!-- The user-displayable name of the provider supplying the plug-in. -->
<!ATTLIST plugin provider-name CDATA #IMPLIED>

<!--
 ! The name of the plug-in class for this plug-in.
 ! The class must be a subclass of org.apache.nutch.plugin.Plugin
 !-->
<!ATTLIST plugin class CDATA #IMPLIED>


<!-- 
 ! The <requires> section of the manifest declares
 ! any dependencies on other plug-ins.
 !-->
<!ELEMENT requires (import+)>


<!-- Each dependency is specified using an <import> element. -->
<!ELEMENT import EMPTY>

<!-- The identifier of the required plug-in. -->
<!ATTLIST import plugin CDATA #REQUIRED>


<!--
 ! The <runtime> section of the manifest contains a definition of one or more
 ! libraries that make up the plug-in runtime.
 ! The referenced libraries are used by the plugin execution mechanisms
 ! (the plug-in class loader) to load and execute the correct code required by
 ! the plug-in.
 !-->
<!ELEMENT runtime (library+)>


<!--
 !The <library> elements collectively define the plug-in runtime.
 ! At least one <library> must be specified.
 !-->
<!ELEMENT library (export*)>

<!--
 ! A string reference to a library file or directory containing classes
 ! (relative to the plug-in install directory).
 ! Directory references must contain trailing file separator.
 !-->
<!ATTLIST library name CDATA #REQUIRED>


<!--
 ! Each <library> element can specify which portion
 ! of the library should be exported.
 ! The export rules are specified as a set of export masks.
 ! By default (no export rules specified),
 ! the library is considered to be private.
 ! Each export mask is specified using the name attribute.
 !-->
<!ELEMENT export EMPTY>

<!--
 ! The export mask can have the following values:
 !   * - indicates all contents of library are exported (public)
 !   package.name.* - indicates all classes in the specified package
 !                    are exported. The matching rules are the same as in the
 !                    Java import statement.
 !   package.name.ClassName - fully qualified java class name
 !
 ! NOTE : export mask is not yet implemented in Nutch.
 !-->
<!ATTLIST export name CDATA #REQUIRED>


<!--
 ! Nutch's architecture is based on the notion of configurable extension points.
 ! Nutch itself predefines a set of extension points that cover the task of
 ! extending it (for example, adding parser, indexing filter, ...).
 ! In addition to the predefined extension points, each supplied plug-in can
 ! declare additional extension points. By declaring an extension point the
 ! plug-in is essentially advertising the ability to configure the plug-in
 ! function with externally supplied extensions.
 !-->
<!ELEMENT extension-point EMPTY>

<!-- A user-displayable name for the extension point. -->
<!ATTLIST extension-point name CDATA #REQUIRED>

<!-- A simple id, unique within this plug-in -->
<!ATTLIST extension-point id CDATA #REQUIRED>


<!--
 ! Actual extensions are configured into extension points
 ! (predefined, or newly declared in this plug-in) in the <extension> section.
 !
 ! The configuration information is specified by at least one implementation
 ! with some parameters.
 !-->
<!ELEMENT extension (implementation+)>

<!-- 
 ! A reference to an extension point being configured.
 ! The extension point can be one defined in this plug-in or another plug-in.
 !-->
<!ATTLIST extension point CDATA #REQUIRED>

<!--
 ! Optional identifier for this extension point configuration instance.
 ! This is used by extension points that need to uniquely identify
 ! (rather than just enumerate) the specific configured extensions.
 ! The identifier is specified as a simple token unique within the definition
 ! of the declaring plug-in. When used globally, the extension identifier
 ! is qualified by the plug-in identifier.
 ! FIXME : Seems it is never read in the code.
 !-->
<!ATTLIST extension id CDATA #IMPLIED>

<!--
 ! A user-displayable name for the extension.
 ! FIXME : Seems it is never read in the code.
 !-->
<!ATTLIST extension name CDATA #IMPLIED>


<!--
 ! Defines a specific implementation for the extension.
 ! This implementation can define some special name/value parameters
 ! used at runtime.
 !-->
<!ELEMENT implementation (parameter*)>

<!-- A unique identifier for this implementation -->
<!ATTLIST implementation id CDATA #REQUIRED>

<!-- The fully-qualified Java Class that implements this extension-point -->
<!ATTLIST implementation class CDATA #REQUIRED>


<!-- Defines a name/value parameter -->
<!ELEMENT parameter EMPTY>

<!-- The parameter's name (should be unique for an extension) -->
<!ATTLIST parameter name CDATA #REQUIRED>

<!-- The parameter's value -->
<!ATTLIST parameter value CDATA #REQUIRED>