The following issue has been updated:
Updater: Brett Porter (mailto:[EMAIL PROTECTED])
Date: Wed, 2 Mar 2005 9:55 PM
Comment:
this requires the use of maven-artifact from m2
Changes:
Fix Version changed from 1.1
Fix Version changed to 1.1-beta-1
Component changed from core
Version changed from 1.1
---------------------------------------------------------------------
For a full history of the issue, see:
http://jira.codehaus.org/browse/MAVEN-1127?page=history
---------------------------------------------------------------------
View the issue:
http://jira.codehaus.org/browse/MAVEN-1127
Here is an overview of the issue:
---------------------------------------------------------------------
Key: MAVEN-1127
Summary: decouple artifact type implementations from maven core
Type: New Feature
Status: Unassigned
Priority: Major
Original Estimate: 6 hours
Time Spent: Unknown
Remaining: 6 hours
Project: maven
Fix Fors:
1.1-beta-1
Assignee:
Reporter: John Casey
Created: Thu, 22 Jan 2004 2:22 PM
Updated: Wed, 2 Mar 2005 9:55 PM
Environment: all
Description:
This is a copy of the proposal email I send to the dev list
(http://nagoya.apache.org/eyebrowse/[EMAIL PROTECTED]&msgNo=13740):
While I find the plugin architecture of maven to be fantastic, I have run into
a somewhat serious barrier to my own plugin development
efforts: adding support for new artifacts requires some pretty significant
changes to the maven core, and results in a requirement that I maintain a patch
for each artifact type.
The Problem
----------------------------
The concept of artifact types is intimately coupled with the rest of the maven
core implementation. There seems to be no real compelling reason for this; each
artifact type has a base set of operations which can be performed against it
(with high overlap between types: install, install-snapshot, deploy,
deploy-snapshot), and one or more plugins which are the primary
producers/consumers of it. While I would agree that certain artifact types are
fundamental to maven operation, it can also be stated that certain plugins are
similarly fundamental. Therefore, for these plugins, the concept of decoupling
via plugin architecture is flawed. In order to change the plugin in any
significant way, a change to the maven core may be required to support changes
to the artifact type. In addition, this inherently limits plugin development by
giving a hard-and-fast set of artifact types which can be manipulated by maven.
The Solution
---------------------------
Simply put, decouple artifact type implementations from the maven core. Instead
of having a concrete implementation specifying attributes about a .jar, EJB, or
.pom, factor out the common behavior (aforementioned permutations of install
and deploy) into an interface, called ArtifactTypeHandler. Then, create
concrete implementations of this interface for each type. Finally, add a new
dynamic type handler loader (factory class) which will do the following:
1. Pull the <type>typename</type> attribute from a dependency, or otherwise
arrive at the artifact type desired.
2. Read the classpath resource META-INF/artifactTypes/typename; line 1 of this
file specifies the fully-qualified class name for the type handler.
3. Instantiate this handler class, and return it as the implementation to use
in manipulating this artifact.
This is a variation on the JAR service discovery method specified in the
JDK1.3, and allows each _plugin_ to add an artifact type handler for its own
use. Unrecognized artifact types (i.e. the handler jar is not in the classpath,
and therefore the META-INF/artifactTypes/typename resource is not present) can
be ignored or throw an exception.
Justification
------------------------
Under this new architecture, the only artifact-related code in maven-core is
the ArtifactTypeHandlerFactory and the abstract [interface]
ArtifactTypeHandler. This frees maven up to be a general build tool, agnostic
of what type of artifacts it is handling. DLL's, C headers, configuration
files, etc. are all perfectly usable within the maven repository scheme. Maven
is only limited by the plugins available for it at this point, and plugin
development is not limited by the release cycle for maven-core.
I can produce a patch against maven to accomplish this, if there is adequate
interest...
---------------------------------------------------------------------
JIRA INFORMATION:
This message is automatically generated by JIRA.
If you think it was sent incorrectly contact one of the administrators:
http://jira.codehaus.org/secure/Administrators.jspa
If you want more information on JIRA, or have a bug to report see:
http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
