[MNG-5347] Support expression language in ${...}

• Type: Wish
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 3.0.4
• Component/s: General

Environment

mistria@mistria--rh:~$ mvn -version
Apache Maven 3.0.4 (r1232337; 2012-01-17 09:44:56+0100)
Maven home: /home/mistria/apps/apache-maven-3.0.4
Java version: 1.6.0_24, vendor: Sun Microsystems Inc.
Java home: /usr/lib/jvm/java-6-openjdk-amd64/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "3.2.0-30-generic", arch: "amd64", family: "unix"

• Assignee: Unassigned
• Reporter: Mickael Istria
• Created: 19/Sep/12 03:35
• Updated: 05/Apr/15 22:17
• Resolved: 23/Jan/14 13:18

Description

Use-case:
I want to give as input of my surefire-plugin

<configuration>
    <skip>${skipTests} || ${skipDownloadRuntimes}</skip>
<configuration>

This won't work because the expressions are not evaluated. Boolean arguments in plugin are set to something like Boolean.parseBoolean, which is quite limited.

Instead, we could think of introducing an expression language, such as Groovy, that would allow expressions as parameters for plugins.
Then let's say skipTests=false and skipDownloadRuntimes=true, Maven would first replace "${skipTests} || ${skipDownloadRuntimes}" by "false || true" and then this evaluator would evaluate that to "false", and skip will receive the value "false".

This would for sure make maven less verbose in some cases.

EDIT (thanks Ondrej for inspiring commnent)
Actually, this syntax would make more sense, and allow an expression language:

<configuration>
    <skip>${skipTests|| skipDownloadRuntimes}</skip>
<configuration>

Issue Links

• is duplicated by: MNG-5333 Support expressions for plugin parameters
• is related to: MNG-5194 Profile activation: Allow expressions in <activation>
• relates to: ARCHETYPE-406 Support of velocity expressions for user-defined properties