From b9421dc80af485591a9c50cc8921f912e0def11e Mon Sep 17 00:00:00 2001 From: Ashlee Young Date: Fri, 23 Oct 2015 10:05:40 -0700 Subject: Removing sources to replace with download links instead. Change-Id: Ie28789a725051aec0d1b04dd291b7690a7898668 Signed-off-by: Ashlee Young --- .../ant/apache-ant-1.9.6/manual/projecthelper.html | 150 --------------------- 1 file changed, 150 deletions(-) delete mode 100644 framework/src/ant/apache-ant-1.9.6/manual/projecthelper.html (limited to 'framework/src/ant/apache-ant-1.9.6/manual/projecthelper.html') diff --git a/framework/src/ant/apache-ant-1.9.6/manual/projecthelper.html b/framework/src/ant/apache-ant-1.9.6/manual/projecthelper.html deleted file mode 100644 index fa07aea4..00000000 --- a/framework/src/ant/apache-ant-1.9.6/manual/projecthelper.html +++ /dev/null @@ -1,150 +0,0 @@ - - - - - - -The Apache Ant frontend: ProjectHelper - - - -

The Apache Ant frontend: ProjectHelper

- -

What is a ProjectHelper?

- -

-The ProjectHelper in Apache Ant is responsible for parsing the build file -and creating java instances representing the build workflow. It also signals which -kind of file it can parse, and which file name it expects as default input file. -

- -

-Ant' default ProjectHelper -(org.apache.tools.ant.helper.ProjectHelper2) parses the -usual build.xml files. And if no build file is specified on the command line, it -will expect to find a file named build.xml. -

- -

-The immediate benefit of a such abstraction it that it is possible to make Ant -understand other kind of descriptive languages than XML. Some experiments have -been done around a pure java frontend, and a groovy one too (ask the dev mailing -list for further info about these). -

- -

Since Ant 1.8.2, the import task will also -try to use the proper helper to parse the imported file. So it is possible to -write different build files in different languages and have them import each -other. -

- -

How is Ant is selecting the proper ProjectHelper

- -

-Ant knows about several implementations of ProjectHelper -and has to decide which to use for each build file. -

- -

At startup Ant lists the all implementations found and keeps them -in the same order they've been found in an internal 'repository': -

the first to be searched for is the one declared by the system property - org.apache.tools.ant.ProjectHelper (see - Java System Properties);
then it searches with its class loader for a ProjectHelper - service declarations in the META-INF: it searches in the classpath for a - file META-INF/services/org.apache.tools.ant.ProjectHelper. - This file will just contain the fully qualified name of the - implementation of ProjectHelper to instanciate;
it will also search with the system class loader for - ProjectHelper service declarations in the META-INF;
last but not least it will add its default ProjectHelper - that can parse classical build.xml files.

-In case of an error while trying to instanciate a ProjectHelper, Ant -will log an error but won't stop. If you want further debugging -info about the ProjectHelper internal 'repository', use the system -property ant.project-helper-repo.debug and set it to -true; the full stack trace will then also be printed. -

- -

-When Ant is expected to parse a file, it will ask the -ProjectHelper repository to find an implementation that will be -able to parse the input file. Actually it will just iterate over the ordered list -and the first implementation that returns true to -supportsBuildFile(File buildFile) will be selected. -

- -

-When Ant is started and no input file has been specified, it will search for -a default input file. It will iterate over list of ProjectHelpers -and will select the first one that expects a default file that actually exist. -

- -

Writing your own ProjectHelper

- -

-The class org.apache.tools.ant.ProjectHelper is the API expected to -be implemented. So write your own ProjectHelper by extending that -abstract class. You are then expected to implement at least the function -parse(Project project, Object source). Note also that your -implementation will be instanciated by Ant, and it is expecting a default -constructor with no arguments. -

- -

-There are some functions that will help you define what your helper is -capable of and what is is expecting: -

getDefaultBuildFile(): defines which file name is expected if - none provided
supportsBuildFile(File buildFile): defines if your parser - can parse the input file
canParseAntlibDescriptor(URL url): whether your - implementation is capable of parsing a given Antlib - descriptor. The base class returns false
parseAntlibDescriptor(Project containingProject, URL - source): invoked to actually parse the Antlib - descriptor if your implementation returned true - for the previous method.

- -

-Now that you have your implementation ready, you have to declare it to Ant. Three -solutions here: -

use the system property org.apache.tools.ant.ProjectHelper - (see also the Java System Properties);
use the service file in META-INF: in the jar you will build with your - implementation, add a file - META-INF/services/org.apache.tools.ant.ProjectHelper. - And then in this file just put the fully qualified name of your - implementation
use the projecthelper task (since - Ant 1.8.2) which will install dynamically an helper in the internal helper - 'repository'. Then your helper can be used on the next call to the - import task.

- - - - -- cgit 1.2.3-korg