Profile Activation Advanced

Profile Activation Advanced is a Maven extension enabling a profile to be activated with an MVEL expression.

This extension works by overriding Maven's profile property activation mechanism. If an MVEL expression is specified and does not evaluate to true, control is passed to the normal property activation mechanism.

This is a fork of EL Profile Activator Extension. Profile Activation Advanced contains the following improvements over EL Profile Activator Extension:

• Supports specifying the identifier of the properties map for the MVEL expression. This enables support for property names containing invalid MVEL identifier characters (e.g., a dot as in foo.env).

• Published to the Central Repository.

Prerequisites

• Maven 3.3.1 or later
• MVEL 2.4.3.Final

Install

Sadly, Profile Activation Advanced cannot be loaded via Maven's .mvn/extensions.xml core extension mechanism because it would be loaded too late thus preventing it from overriding Maven's built-in profile property activation mechanism.

To install Profile Activation Advanced, install the following JARs to an appropriate location and arrange for them to be found on Maven's class search path:

• profile-activation-advanced-0.2.0.jar
• mvel2-2.4.3.Final.jar

There are various ways to do this:

• Place the JARs in Maven's lib/ext directory.

• Place the JARs under your project's lib-ext directory (or wherever you like) and add to the MAVEN_OPTS environment variable the option -Dmaven.ext.class.path=<JAR-paths>, where <JAR-paths> is a colon-separated list of absolute paths to the JARs placed in your project's lib-ext directory. The difficulty here is that the paths need to be absolute so that they will work even when the current working directory is not the project's root directory.

• Do the same as the preceding approach, but instead of adding to the MAVEN_OPTS environment variable, add to your project's .mvn/maven.config. This has the same problem of needing absolute paths.

• Use Maven Wrapper for your project and patch it to download the needed JARs, install them to your project's lib-ext directory, and add the -Dmaven.ext.class.path=<JAR-paths> option from the preceding approach to the final Maven execution. (Even better would be to submit a PR to the Maven Wrapper project to add support for loading an optional Maven Wrapper extension script from the project's root (e.g., mvnw.local and mvnw.local.cmd) so that the extra behavior could go in the local extension scripts, and you wouldn't need to patch the Maven Wrapper scripts.) Since the wrapper knows the absolute path to the project's root, the absolute paths to the JARs can be determined correctly every time it is run.

Use

In a profile activation property element (e.g., at the XPath /project/profiles/profile/activation/property in a POM), set the name element to paa:mvel and the value element to an MVEL expression. System and user properties are accessible as identifiers in the MVEL expression. If the MVEL expression needs to access a property that has a character in its name that is not a valid MVEL identifier (e.g., a dot as in foo.env), a properties map identifier can be specified in parentheses after paa:mvel in the name element. For example, to specify the identifier p for the properties map, set the name element to paa:mvel(p); the identifier p can then be used in the MVEL expression to access any of the available properties (e.g., p["foo.env"]).

Examples

Activate the POM's foo_env-development profile if the foo_env property is either not set or is set to development:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
        http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.example.foo</groupId>
  <artifactId>foo</artifactId>
  <version>1.0.0</version>
  <packaging>pom</packaging>
  <profiles>
    <profile>
      <id>foo_env-development</id>
      <activation>
        <property>
          <name>paa:mvel</name>
          <value>(!isdef foo_env) || foo_env == "development"</value>
        </property>
      </activation>
    </profile>
  </profiles>
</project>

The following examples are given as MVEL expressions, not as MVEL expressions encoded as XML content. All of these can be included without modification in XML if they appear inside a CDATA section (e.g., <![CDATA[isdef foo && foo == "abc"]]>). If they do not appear inside a CDATA section, but rather appear as regular markup (i.e., element content), then reserved XML characters must be replaced with their appropriate XML entities (e.g., & must be replaced with &).

foo and bar are defined and have the same value:

isdef foo && isdef bar && foo == bar

foo is defined while bar is not:

isdef foo && !isdef bar

foo starts with abc, or baz contains xyz:

(isdef foo && foo.startsWith("abc")) || (isdef baz && baz.contains("xyz"))

With the properties map identifier set to p, foo.env equals test:

isdef foo.env && p["foo.env"] == "test"