Ant 101 - Intro & Why You Should Check It Out
Last week I decided to take a look at Ant. I have heard good things about it in the past, but never really took notice of what it could do until recently. I hesitated on posting this because after I did some manual digging and learning I discovered that Andy Jarrett has quite a number of very helpful posts about Ant but I decided to go ahead and post it as an intro to folks who are new to it.
So what is Ant?
Well the answer according to the FAQs on ant.apache.org tell us:
Ant is a Java-based build tool. In theory, it is kind of like Make, without Make's wrinkles and with the full portability of pure Java code.
Nice. But I don't have a clue what the hell Make is so that description is no good to me. Reading a little further we see the following:
According to Ant's original author, James Duncan Davidson, the name is an acronym for "Another Neat Tool".Later explanations go along the lines of "ants do an extremely good job at building things", or "ants are very small and can carry a weight dozens of times their own" - describing what Ant is intended to be.
So that explains it a little better. Basically Ant helps you automate monotonous repetitive tasks like moving/renaming files and directories, zipping and unzipping, replacing text strings within a file or group of files, and much more. Why would a ColdFusion developer care about Ant? Picture a script that pushes your development sites to production with one click. Now you begin to see the power of Ant.
How difficult is it to learn Ant?
At it's core Ant is nothing more then a tag based syntax. Sweet. I like tags. They're easy to use and I'm used to them since I use CF and Flex.
So how 'bout some code?
You can install Ant outside of Eclipse, but since it's already built into Eclipse I think it's a little nicer to take advantage of that fact and use the built in version. An Ant project is created in Eclipse by simply creating a file called build.xml and saving it in a project. Immediately you'll notice that Eclipse recognizes the Ant script and identifies it in your Project Navigator with an icon with, well, an Ant.
<target name="hello">
<echo message="Hello, World"/>
</target>
</project>
Paste that into Eclipse and save as build.xml. You can run the task several ways. The first option is typing Alt+Shift+X, Q. Eclipse will prompt you to save any unsaved files and should then output the following in the console:
hello:
[echo] Hello, World
BUILD SUCCESSFUL
Total time: 203 milliseconds
What about having a project with multiple targets? Well that may look like this example (again borrowed from the Getting Started guide):
<target name="hello">
<echo message="Hello, World"/>
</target>
<target name="goodbye">
<echo message="Goodbye, Cruel World"/>
</target>
<target name="all" depends="hello,goodbye" />
</project>
I've jumped a bit ahead because I think this is basic stuff at this point and introduced a third target named 'all' with an attribute of depends. This tag tells Ant about tasks that have dependencies on one another. You can imagine how this could be valuable in more complex projects. So go ahead and run this task in Eclipse. You'll notice that we get the same 'Hello World' echo but not the 'Goodbye' echo. In this case Ant ran our default target that was specified in the <project> tag. To get all the targets to run we can select Run - External Tools - External Tools and we are presented with the menu illustrated below. If we choose the target tab we will see all of our targets listed.
Select All - Apply - Run and you'll see the following in the console.
hello:
[echo] Hello, World
goodbye:
[echo] Goodbye, Cruel World
all:
BUILD SUCCESSFUL
Total time: 203 milliseconds
So thats about it for a basic intro to Ant. I could go further with a more real life use case, but I'm not sure. Would there be interest in that? Andy's blog does have some very good examples and I'd hate to rehash what he's already touched on.
Resources
Andy Jarrett's Ant Category
Getting Started With Ant
Ant Manual
http://www.thecrumb.com/wiki/Ant
And I just added yours :)
What makes this helpful is the bringing together combined knowledge, and that in itself is always a good thing.
Keep going!
@Everyone else - cool. I'll post a real life example within the next few days. Thanks.
Btw, if you really don't know what "make" is: it's a build tool for C++. You create a "make" file (called excatly "makefile") that defines what happens when you compile a program in C++. Usually, in C++ you need prerequisites before you can build the final executable (such as including headers and other libraries), so make automated that by looking for the makefile in the same directory and executing the specified tasks before the actual build.
<?xml version="1.0" encoding="utf-8"?>
<project name="myproject" default="all">
<target name="all" depends="hello,goodbye"/>
<target name="hello">
<echo message="Hello, world!"/>
</target>
<target name="goodbye">
<echo message="Goodbye!"/>
</target>
</project>