How can I find out which of two numeric properties is the greatest?
Here's how to check wheather two are equal:
<condition property="isEqual">
<equals arg1="1" arg2="2"/>
</condition>
The Ant script task allows you to implement a task in a scripting language. If you have JDK 1.6 installed, Ant can execute JavaScript without needing any additional dependent libraries. For example, this JavaScript reads an Ant property value and then sets another Ant property depending on a condition:
<property name="version" value="2"/>
<target name="init">
<script language="javascript"><![CDATA[
var version = parseInt(project.getProperty('version'));
project.setProperty('isGreater', version > 1);
]]></script>
<echo message="${isGreater}"/>
</target>
Unfortunately, Ant's built in condition task does not have an IsGreaterThan element. However, you could use the IsGreaterThan condition available in the Ant-Contrib project. Another option would be to roll out your own task for greater than comparison. I'd prefer the former, because it's easier and faster, and you also get a host of other useful tasks from Ant-Contrib.
If you don't want to (or cannot) use the Ant-Contrib libraries, you can define a compare task using javascript:
<!-- returns the same results as Java's compareTo() method: -->
<!-- -1 if arg1 < arg2, 0 if arg1 = arg2, 1 if arg1 > arg2 -->
<scriptdef language="javascript" name="compare">
<attribute name="arg1" />
<attribute name="arg2" />
<attribute name="result" />
<![CDATA[
var val1 = parseInt(attributes.get("arg1"));
var val2 = parseInt(attributes.get("arg2"));
var result = (val1 > val2 ? 1 : (val1 < val2 ? -1 : 0));
project.setProperty(attributes.get("result"), result);
]]>
</scriptdef>
You can use it like this:
<property name="myproperty" value="20" />
...
<local name="compareResult" />
<compare arg1="${myproperty}" arg2="19" result="compareResult" />
<fail message="myproperty (${myproperty}) is greater than 19!">
<condition>
<equals arg1="${compareResult}" arg2="1" />
</condition>
</fail>
Related
I am basically trying to do the following thing in Ant (v1.9.4):
I have a list of fixed string like {a,b,c,d} --> First how should I declare this in Ant?
Then I have an input parameter such as ${mystring} and I want to check if the variable value is in my list. Which means in this example, if the variable value is equals to a or b or c or d.
If so return true else false (or 0 and 1 something like that).
Is there a simple way to do that?
Thanks,
Thiago
Use ant property task to declare your stringlist.
Use ant contains condition to check whether list contains a specific item.
Something like :
<project>
<!-- your stringlist -->
<property name="csvprop" value="foo,bar,foobar"/>
<!-- fail if 'foobaz' is missing -->
<fail message="foobaz not in List => [${csvprop}]">
<condition>
<not>
<contains string="${csvprop}" substring="foobaz"/>
</not>
</condition>
</fail>
</project>
Or wrap it in a macrodef for resuse :
<project>
<!-- your stringlist -->
<property name="csvprop" value="foo,bar,foobar"/>
<!-- create macrodef -->
<macrodef name="listcontains">
<attribute name="list"/>
<attribute name="item"/>
<sequential>
<fail message="#{item} not in List => [#{list}]">
<condition>
<not>
<contains string="${csvprop}" substring="foobaz"/>
</not>
</condition>
</fail>
</sequential>
</macrodef>
<!-- use macrodef -->
<listcontains item="foobaz" list="${csvprop}"/>
</project>
-- EDIT --
From ant manual condition :
If the condition holds true, the property value is set to true by default; otherwise, the property is not set. You can set the value to something other than the default by specifying the value attribute.
So simply use a condition to create a property that is either true or not set, f.e. combined with the new if/unless feature introduced with Ant 1.9.1 :
<project
xmlns:if="ant:if"
xmlns:unless="ant:unless"
>
<!-- your stringlist -->
<property name="csvprop" value="foo,bar,foobar"/>
<!-- create macrodef -->
<macrodef name="listcontains">
<attribute name="list"/>
<attribute name="item"/>
<sequential>
<condition property="itemfound">
<contains string="${csvprop}" substring="foobaz"/>
</condition>
<!-- echo as example only instead of
your real stuff -->
<echo if:true="${itemfound}">Item #{item} found => OK !!</echo>
<echo unless:true="${itemfound}">Warning => Item #{item} not found !!</echo>
</sequential>
</macrodef>
<!-- use macrodef -->
<listcontains item="foobaz" list="${csvprop}"/>
</project>
output :
[echo] Warning => Item foobaz not found !!
Note that you need the namespace declarations to activate the if/unless feature.
What is the simplest implementation to restrict values to a property?
property name="prop_name" value="${dynamic_value}
I want to have the values to ${dynamic_value} from a restricted set.
Thanks,
Wajid
You may use a scriptcondition (see ant manual conditions) with builtin javascript engine(included in Java >= 1.6.x), f.e. :
<project>
<property name="foo" value="26"/>
<fail message="Value of $${foo} not in range => [${foo}] !">
<condition>
<scriptcondition language="javascript">
var foo = parseInt(project.getProperty("foo"));
self.setValue(foo <= 20 || foo >= 25);
</scriptcondition>
</fail>
</project>
In Ant, how can I test if a property ends with a given value?
For example
<property name="destdir"
value="D:\FeiLong Soft\Essential\Development\repository\org\springframework\spring-beans" />
how can I test if ${destdir} ends with "spring-beans"?
additional：
In my ant-contrib-1.0b3.jar, without 'endswith' task~~
You can test if ${destdir} ends with "spring-beans" like this (assuming you have ant-contrib, and are using Ant 1.7 or later).
<property name="destdir" value="something\spring-beans" />
<condition property="destDirHasBeans">
<matches pattern=".*spring-beans$" string="${destdir}" />
</condition>
<if>
<equals arg1="destDirHasBeans" arg2="true" />
<then>
$destdir ends with spring-beans ...
</then>
<else> ...
</else>
</if>
The '$' in the regex pattern ".*spring-beans$" is an anchor to match at the end of the string.
As Matteo, Ant-Contrib contains a lot of nice stuff, and I use it heavily.
However, in this case can simply use the <basename> task:
<basename property="basedir.name" file="${destdir}"/>
<condition property="ends.with.spring-beans">
<equals arg1="spring-beans" arg2="${basedir.name}"/>
<condition>
The property ${ends.with.spring-beans} will contain true if ${destdir} ends with string-beans and false otherwise. You could use it in the if or unless parameter of the <target> task.
You can use the EndWith condition from Ant-Contrib
<endswith string="${destdir}" with="spring-beans"/>
For example
<if>
<endswith string="${destdir}" with="spring-beans"/>
<then>
<!-- do something -->
</then>
</if>
Edit
<endswith> is part of the Ant-Contrib package that has to be installed and enabled with
<taskdef resource="net/sf/antcontrib/antlib.xml"/>
The JavaScript power can be used for string manipulation in the ANT:
<script language="javascript"> <![CDATA[
// getting the value for property sshexec.outputproperty1
str = project.getProperty("sshexec.outputproperty1");
// get the tail , after the separator ":"
str = str.substring(str.indexOf(":")+1,str.length() ).trim();
// store the result in a new property
project.setProperty("res",str);
]]> </script>
<echo message="Responce ${res}" />
I've a build script built in Ant which has a macrodef that takes a few default parameters, target, root and the like, and then an optional two, extrasrc-f and extrasrc-c. After they've come in, I like to do a uptodate check on all relevant resources, then only do a build if the target is out of date.
What I have at the moment,
<?xml version="1.0" encoding="UTF-8"?>
<project name="Custom build" default="default">
<taskdef resource="net/sf/antcontrib/antlib.xml"
classpath="C:/dev/ant/ant-contrib/ant-contrib-1.0b3.jar"/>
<macrodef name="checkuptodate">
<attribute name="target" />
<element name="resource" />
<sequential>
<condition property="needbuild">
<and>
<resourcecount when="greater" count="0"> <resource /> </resourcecount>
<not>
<uptodate targetfile="#{target}">
<srcresources> <resource /> </srcresources>
</uptodate>
</not>
</and>
</condition>
</sequential>
</macrodef>
<macrodef name="projbuild">
<attribute name="root" />
<attribute name="target" />
<element name="extrasrc-f" optional="true" />
<element name="extrasrc-c" optional="true" />
<sequential>
<local name="needbuild" />
<checkuptodate target="#{root}/bin/#{target}">
<resource>
<union>
<extrasrc-f />
<fileset dir="#{root}/src" includes="**/*.java" />
</union>
</resource>
</checkuptodate>
<if>
<istrue value="${needbuild}" />
<then>
<javac
srcdir="#{root}/src"
destdir="#{root}/bin"
includeantruntime="false"
>
<extrasrc-c />
</javac>
</then>
</if>
</sequential>
</macrodef>
<target name="default">
<projbuild root="." target="EntryPoint.class">
<extrasrc-f>
<fileset dir="Proj2/src" includes="**/*.java" />
<fileset dir="Proj3/src" includes="**/*.java" />
</extrasrc-f>
<extrasrc-c>
<classpath location="Proj2/src" />
<classpath location="Proj3/src" />
</extrasrc-c>
</projbuild>
</target>
</project>
But as you can see, at this point in time, for me it's inefficient, to do what I want, I've to create and pass in at least one fileset, and multiple classpaths. What I'd really like to do is just pass in a list of directories, then create the extrasrc-f and extrasrc-c elements on the fly from that information, but for the life of me, I've no idea how I'm able to do that.
I've read up plenty about many of Ant and Ant-Contrib funky classes, but I haven't read anything that would allow me to do something like this, which I do find odd, because to me it looks an obvious situation.
Am I approaching this in a very wrong way, or is there something I'm missing? If I'm really misusing Ant, I'd love pointers in the right direction about how to do this properly, create a catchall, template build in a macrodef (or target, if that's the only way to do it) which tests multiple source files against one file that gets built, while also passing in extra class or library paths too, preferably in one single list.
Perhaps you can use a couple of <scriptdef> tasks to help break up those macros.
First, one that takes a comma-separated list of directories and generates the <union> from them. You supply the refid you want to use to refer to the union as the id attribute. There are optional includes and excludes.
<scriptdef name="dirs2union" language="javascript">
<attribute name="dirs" />
<attribute name="id" />
<attribute name="includes" />
<attribute name="excludes" />
<![CDATA[
var dirs = attributes.get( "dirs" ).split( "," );
var includes = attributes.get( "includes" );
var excludes = attributes.get( "excludes" );
var union = project.createDataType( "union" );
project.addReference( attributes.get( "id" ), union );
for ( var i = 0; i < dirs.length; i++ ) {
var fs = project.createDataType( "fileset" );
fs.setDir( new java.io.File( dirs[i] ) );
if ( includes )
fs.setIncludes( includes );
if ( excludes )
fs.setExcludes( excludes );
union.add( fs );
}
]]>
</scriptdef>
The second - very similar - script does the equivalent for path generation:
<scriptdef name="dirs2path" language="javascript">
<attribute name="dirs" />
<attribute name="id" />
<![CDATA[
var dirs = attributes.get( "dirs" ).split( "," );
var path = project.createDataType( "path" );
project.addReference( attributes.get( "id" ), path );
for ( var i = 0; i < dirs.length; i++ ) {
var pe = project.createDataType( "path" );
pe.setLocation( new java.io.File( dirs[i] ) );
path.add( pe );
}
]]>
</scriptdef>
An example use might then be something like:
<property name="dirs" value="Proj2/src,Proj3/src" />
<dirs2union dirs="${dirs}" id="my.union" includes="**/*.java" />
<dirs2path dirs="${dirs}" id="my.path" />
... later (e.g.) ...
<union refid="my.union" />
<classpath refid="my.path" />
You could then modify your macros to either take the dirs attribute and generate the union and classpath internally, or perhaps generate these once elsewhere and just pass in the references.
I've not attempted to include the #{root} directories in this illustration, but it should be possible to adapt the above for that.
Hi all this is my code for target calling.
<target name="abc">
<var name="x" value="10"/>
<antcall target="def"/>
<!--Again Access The value of x here and also change it here-->
</target>
<target name="def">
<!--Access The value of x here and also change it here-->
</target>
and also i want to access this X in other build file,is there any way
This is not possible with ant. In an properties are immutable and cannot be reset. The var task from ant contrib can be used to override values, but should be used sparingly.
You could use a temporary file to achieve what you want. But probably you are trying something weird, which can be solved in a different way.
This would also work across buildfiles if they have access to the property file.
<target name="abc">
<var name="x" value="10"/>
<antcall target="def"/>
<!--Again Access The value of x here and also change it here-->
<var unset="true" file="myproperty.properties" /> <!-- read variable from property file-->
</target>
<target name="def">
<echo file="myproperty.properties" append="false">x=12</echo> <!-- create a new propertyfile-->
</target>
For the sake of justice, there is a hack that allows to alter ant's immutable properties without any additional libs (since java 6):
<scriptdef name="propertyreset" language="javascript"
description="Allows to assing #{property} new value">
<attribute name="name"/>
<attribute name="value"/>
project.setProperty(attributes.get("name"), attributes.get("value"));
</scriptdef>
Usage:
<target name="abc">
<property name="x" value="10"/>
<antcall target="def"/>
</target>
<target name="def">
<propertyreset name="x" value="11"/>
</target>
As #oers mentioned, this should be used with care after all canonical approaches proved not to fit.
It is difficult to suggest further without knowing the goal behind the question.