/*
* Copyright 2013 the original author or authors.
*
* Licensed 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.
*/
package org.gradle.plugin.use;
import org.gradle.api.Incubating;
/**
* The DSL for declaring plugins to use in a script.
* <p>
* In a build script, the <code>plugins {}</code> script block API is of this type.
* That is, you can use this API in the body of the plugins script block to declare plugins to be used for the script.
* </p>
* <h3>Relationship with the apply() method</h3>
* <p>
* The <code>plugins {}</code> block serves a similar purpose to the {@link org.gradle.api.plugins.PluginAware#apply(java.util.Map)} method
* that can be used to apply a plugin directly to a {@code Project} object or similar.
* A key difference is that plugins applied via the <code>plugins {}</code> block are conceptually applied to the script, and by extension the script target.
* At this time there is no observable practical difference between the two approaches with regard to the end result.
* The <code>plugins {}</code> block is a new, incubating, Gradle feature that will evolve to offer benefits over the {@code apply()} approach.
* </p>
* <h3>Strict Syntax</h3>
* <p>
* The <code>plugins {}</code> block only allows a strict subset of the full build script programming language.
* Only the API of this type can be used, and values must be literal (e.g. constant strings, not variables).
* Moreover, the <code>plugins {}</code> block must be the first code of a build script.
* There is one exception to this, in that the {@code buildscript {}} block (used for declaring script dependencies) must precede it.
* </p>
* <p>
* This implies the following constraints:
* </p>
* <ul>
* <li>Only {@link #id(String)} method calls may be top level statements</li>
* <li>{@link #id(String)} calls may only be followed by a {@link PluginDependencySpec#version(String)} and/or {@link PluginDependencySpec#apply(boolean)} method call on the returned object</li>
* <li>{@link #id(String)}, {@link PluginDependencySpec#version(String)} and {@link PluginDependencySpec#apply(boolean)} methods must be called with a literal argument (i.e. not a variable)</li>
* <li>The <code>plugins {}</code> script block must follow any <code>buildscript {}</code> script block, but must precede all other logic in the script</li>
* </ul>
* <h3>Available Plugins</h3>
* <h4>Core Plugins</h4>
* <p>
* Core Gradle plugins are able to be applied using the <code>plugins {}</code> block.
* Core plugins must be specified without a version number, and can have a <i>qualified</i> or <i>unqualified</i> id.
* That is, the {@code java} plugin can be used via:
* </p>
* <pre>
* plugins {
* id 'java'
* }
* </pre>
* <p>
* Or via:
* </p>
* <pre>
* plugins {
* id 'org.gradle.java'
* }
* </pre>
* <p>
* Core Gradle plugins use the {@code org.gradle} namespace.
* </p>
* <p>
* For the list of available core plugins for a particular Gradle version, please consult the User Guide.
* </p>
* <h4>Community Plugins</h4>
* <p>
* Non-core plugins are available from the <a href="http://plugins.gradle.org">Gradle Plugin Portal</a>.
* These plugins are contributed by users of Gradle to extend Gradle's functionality.
* Visit <a href="http://plugins.gradle.org">plugins.gradle.org</a> to browse the available plugins and versions.
* </p>
* <p>
* To use a community plugin, the fully qualified id must be specified along with a version.
* </p>
*/
@Incubating
public interface PluginDependenciesSpec {
/**
* Add a dependency on the plugin with the given id.
* <p>
* <pre>
* plugins {
* id "org.company.myplugin"
* }
* </pre>
* Further constraints (e.g. version number) can be specified by the methods of the return value.
* <pre>
* plugins {
* id "org.company.myplugin" version "1.3"
* }
* </pre>
*
* Plugins are automatically applied to the current script by default. This can be disabled using the {@code apply false} option:
*
* <pre>
* plugins {
* id "org.company.myplugin" version "1.3" apply false
* }
* </pre>
*
* This is useful to reuse task classes from a plugin or to apply it to some other target than the current script.
*
* @param id the id of the plugin to depend on
* @return a mutable plugin dependency specification that can be used to further refine the dependency
*/
PluginDependencySpec id(String id);
}