ant脚本中私有和公共目标之间的区别

Question

I've recently discovered that there are several useful templates (in Eclipse) that can be added to the script. And among them "public target" and "private target". And here the templates:

public target

    <!-- ================================= 
          target: name              
         ================================= -->
    <target name="name" depends="depends" description="description">

    </target>

private target

    <!-- - - - - - - - - - - - - - - - - - 
          target: name                      
         - - - - - - - - - - - - - - - - - -->
    <target name="name">

    </target>

And i don't get it. What is the main difference? And what does the private target mean? Is it some specific feature in ant scripts or just code beautifying?

Just interesting.

Answer 1

A target which has a description is public because it appears when you execute

ant -projecthelp

The others are considered private because they don't appear by default.

Answer 2

Here's an example

<project name="public_only" default="public">
    <target name="-private">
        <echo message="private" />
    </target>
    <target name="public" description="this task is public" depends="-private">
        <echo message="public" />
    </target>
</project>

Answer 3

private targets, i.e targets which could not be called by the user called in script itself

while

public can be called by user

you often want to call internal / private targets to run just a small step in the build (particularly while developing new features) – you can't do this if the targets are private. so you end up creating a second, public, target that calls the private target … and you end up doubling the size of your build files.