reloading properties after updating a property file - ant

I'm trying to read a property after updating it using propertyfile task. Something like
<property file="test.properties" />
<echo>before :: ${modules}</echo>
<propertyfile file="test.properties" >
<entry key="modules" type="string" operation="+" value="foo" />
</propertyfile>
<property file="${status.path}/test.properties" />
<echo>after :: ${modules}</echo>.
It doesn't seem to load the second time. But the property file is updated.

You can invoke a new ant runtime with the antcall task that ignores the properties of your main target runtime - just make sure to include inheritAll="false"
<target name="main">
<property file="test.properties"/>
<echo>before :: ${modules}</echo>
<propertyfile file="test.properties">
<entry key="modules" type="string" operation="+" value="foo" />
</propertyfile>
<antcall target="second-runtime" inheritAll="false"/>
</target>
<target name="second-runtime">
<property file="${status.path}/test.properties" />
<echo>after :: ${modules}</echo>
</target>
antcall refrence

As sudocode already mentioned, in Core Ant properties are immutable - for good reasons.
With the unset task from Antelope Ant Tasks you're able to unset all properties set in a file with a one liner :
<unset file="test.properties"/>
afterwards
<propertyfile file="test.properties" >
<entry key="modules" type="string" operation="+" value="foo" />
</propertyfile>
will work.
Hint : the task works only for normal properties, not for xmlproperties.
But there's a simple workararound, simply use <echoproperties prefix="..." destfile="foo.properties"/> and afterwards <unset file="foo.properties"/>
If you don't want to use Antelope for that specific task only, you may write a macrodef or own task with similar features.

For this case, when whole properties file is loaded twice, I suggest using different prefixes for the first and second load. First load with aprefix attribute equal to first. Access the properties with this prefix, that is property foo will be accessible as first.foo. Then save the properties file and load again, but this time without a prefix. You will get modified properties in suitable place.
Without using the prefix the second load will do nothing, as ant prevents properties from overriding. Others pointed that already.

Ant properties are immutable - once set, they are fixed. So reloading the properties file will not refresh the value of a property already set.

this macro allow you to change the property value after fixed one
<macrodef name="set" >
<attribute name="name"/>
<attribute name="value"/>
<sequential>
<script language="javascript">
<![CDATA[
project.setProperty("#{name}", "#{value}");
]]>
</script>
</sequential>
</macrodef>

you can create a new properties file and save the property in the new file.
Provide the reference of the file in the next line.
Done :)

Related

ANT Build: Can the token itself be parsed from other values from within the property file?

Can the token itself be parsed from other values from within the property file?
Is it possible to evaluate the token key, without hardcoding the token? Can the token itself be parsed from other values from within the property file?
For example, if the properties file has the following tokens (test.properties):
module_no = 01
module_code = bb
title_01_aa = ABC
title_02_aa = DEF
title_03_aa = GHI
title_01_bb = JKL
title_02_bb = MNO
title_03_bb = PQR
Contents of build.xml
<?xml version="1.0" encoding="utf-8"?>
<project default="repl">
<property file="test.properties" />
<target name="repl">
<replace file="test.txt" token="module_title" value="title_${module_no}_${module_code}" />
</target>
</project>
Sample content with text:
Welcome to module_title.
The replace task will result in:
Welcome to title_01_bb.
How to achieve this instead?
Welcome to JKL.
This might be very basic, but please do guide me in the right direction. Thank you.
Nested property expansion does not work by default in Ant as described in the documentation:
Nesting of Braces
In its default configuration Ant will not try to balance braces in property expansions, it will only consume the text up to the first closing brace when creating a property name. I.e. when expanding something like ${a${b}} it will be translated into two parts:
the expansion of property a${b - likely nothing useful.
the literal text } resulting from the second closing brace
This means you can't use easily expand properties whose names are given by properties, but there are some workarounds for older versions of Ant. With Ant 1.8.0 and the the props Antlib you can configure Ant to use the NestedPropertyExpander defined there if you need such a feature.
If you check the workarounds link, one solution is to use a macrodef to copy the property:
<property file="test.properties" />
<target name="repl">
<gettitleprop name="titleprop" moduleno="${module_no}" modulecode="${module_code}" />
<replace file="test.txt" token="module_title" value="${titleprop}" />
</target>
<macrodef name="gettitleprop">
<attribute name="name"/>
<attribute name="moduleno"/>
<attribute name="modulecode"/>
<sequential>
<property name="#{name}" value="${title_#{moduleno}_#{modulecode}}"/>
</sequential>
</macrodef>

Referencing global Ant property after <local> is used

I can create a local property in Ant within a "block" scope.
But how can I now reference the global property within the same block?
<property name="myprop" value="global"/>
...
<sequential>
<local name="myprop"/>
<property name="myprop" value="local"/>
<echo message="my local prop is ${myprop}"/> //<-- this works fine
<echo message="my global prop is ????"/> //<-- HOW?
</sequential/>
No ant-contrib please.
I'd also like to keep this in Ant, not resorting to JS.
The only thing I could think of was "copying" the global property under a different name to be used in this block
<local name="myglobprop"/>
<property name"myglobprop" value="${myprop}"/>
<local name="myprop"/>
<property name="myprop" value="local"/>
<echo message="my global prop is ${myglobprop}"/>
But that is rather unsightly and seems redundant. I am really just looking for an out-of-scope property reference method.
Edit - use case
My attempt to coerce Ant to do delayed expansion:
Let's say I have a property whose value is a combination of several other properties.
<property name="mycmdline" value="${cmd}=${type}"/>
If ${cmd} and ${type} are known before the above property, all is great. However in my case, these values are not defined (no property set). These values only become known at later stage inside a build macrodef.
I have another simple macrodef that will perform delayed expansion:
<property name="mycmdline" value="${cmd}=${type}"/>
...
<macrodef name="property-expand">
<attribute name="name"/>
<attribute name="value"/>
<sequential>
<fail if="#{name}" message="Property #{name} is already set"/>
<property name="#{name}" value="#{value}"/>
</sequential>
</macrodef>
Finally my build macrodef would contain the following snippet:
<local name="cmd"/>
<local name="type"/>
<local name="mycmdline"/>
<property name="cmd" value="#{cmd}"/>
<property name="type" value="#{type}"/>
<property-expand name="mycmdline" value="${mycmdline}"/>
The last line is obviously wrong. I am creating a (now local) property called mycmdline with expanded value of global (now out of scope) ${mycmdline}. The macrodef for delayed expansion works great on it's own, but the problem is that the global ${mycmdline} is out of scope and cannot be referenced.
What I really wanted is:
<property name="mycmdline" value="${cmd}=${type}"/>
...
<!-- In macrodef now -->
<local name="mycmdline"/>
<property-expand name="mycmdline" value="GLOBAL:${mycmdline}"/>
Instead, what I have to do is:
<property name="unexpanded_mycmdline" value="${cmd}=${type}"/>
...
<!-- In macrodef now -->
<local name="mycmdline"/>
<property-expand name="mycmdline" value="${unexpanded_mycmdline}"/>
Why?
It may not look like a lot of difference, but it's about readability. unexpanded_mycmdline and mycmdline are now two different names, when trying to follow the way the value of property gets used through a script, it now makes a disconnected jump from one property name to another (not matter how similar the names may look). The whole unexpanded_ prefix looks out of place and doesn't fit with the rest of the naming conventions, unless I name all my global variables with some prefix, which doesn't make sense either.

How can I make an ant prompt use the default value if not entered within a given time?

Many ant scripts I write use a default value, and these default values are almost exclusive. I.e. only occasionally will I want to run it without the default values.
A lot of times, these scripts take enough time that it makes sense to go do something else while they run, like getting coffee or using the Little Developer's Room. Of course, if there's a prompt on it, and you forgot it, well, you're SOL.
Is there any way I can put a timeout on the prompt so if it isn't entered in, oh let's say 30 seconds, that it just accepts the default value so that when I get back to my workstation I have my war/jar/whatever ready to go? Something like
<input addproperty="branch.tag"
defaultvalue="dev"
timeout="30000">
Which branch would you like to build?
</input>
Now obviously this timeout feature doesn't exist, but you get the idea of what I'm trying to accomplish.
Option 1: Configure build to run automated or interactive
Rather than timing out the input prompts, you could configure the build to run fully automated by supplying the default input values in a properties file.
default.properties
Which\ branch\ would\ you\ like\ to\ build?=dev
To switch between interactive and automated builds, the type of input handler to use could be specified when invoking Ant:
Automated build
$ ant -Dhandler.type=propertyfile
Interactive build
$ ant -Dhandler.type=default
The input handler would need to be specified using the nested <handler> element.
<input addproperty="branch.tag" defaultvalue="dev"
message="Which branch would you like to build?">
<handler type="${handler.type}" />
</input>
The last step is to specify the properties file for the PropertyFileInputHandler by defining the ant.input.properties system property.
Linux
export ANT_OPTS=-Dant.input.properties=default.properties
Option 2: Use AntContrib Trycatch combined with Parallel in a macrodef
<taskdef name="trycatch" classname="net.sf.antcontrib.logic.TryCatchTask">
<classpath>
<pathelement location="/your/path/to/ant-contrib.jar"/>
</classpath>
</taskdef>
<macrodef name="input-timeout">
<attribute name="addproperty" />
<attribute name="defaultvalue" default="" />
<attribute name="handlertype" default="default" />
<attribute name="message" default="" />
<attribute name="timeout" default="30000" />
<text name="text" default="" />
<sequential>
<trycatch>
<try>
<parallel threadcount="1" timeout="#{timeout}">
<input addproperty="#{addproperty}"
defaultvalue="#{defaultvalue}"
message="#{message}">
<handler type="#{handlertype}" />
#{text}
</input>
</parallel>
</try>
<catch>
<property name="#{addproperty}" value="#{defaultvalue}" />
</catch>
</trycatch>
</sequential>
</macrodef>
<target name="test-timeout">
<input-timeout addproperty="branch.tag" defaultvalue="dev"
message="Which branch would you like to build?"
timeout="5000" />
<echo message="${branch.tag}" />
</target>
Option 3: Write a custom Ant task
Implementation left as an exercise to the reader.

How to pass paramters by refrence in ant

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.

Use ANT to update build number and inject into source code

In my build.xml file I am incrementing a build version number in a property file like so:
<target name="minor">
<propertyfile file="build_info.properties">
<entry key="build.minor.number" type="int" operation="+" value="1" pattern="00" />
<entry key="build.revision.number" type="int" value="0" pattern="00" />
</propertyfile>
</target>
I also have similar entries for the major and revision. (from Build numbers: major.minor.revision)
This works great. Now I would like to take this incremented build number and inject it into my source code:
//Main.as
public static const VERSION:String = "#(#)00.00.00)#";
By using:
<target name="documentVersion">
<replaceregexp file="${referer}" match="#\(#\).*#" replace="#(#)${build.major.number}.${build.minor.number}.${build.revision.number})#" />
</target>
Now this sorta works. It does indeed replace the version but with the outdated version number. So whenever I run the ANT script the build_info.properties is updated to the correct version but my source code file is using the pre updated value.
I have echoed to check that indeed I am incrementing the build number before I call the replace and I have noticed that echoing:
<echo>${build.minor.number}</echo>
//After updating it still shows old non updated value here but the new value in the property file.
So is there a way to retrieve the updated value in the property file so I can use it to inject into my source code?
Cheers
So after spending hours not being able to solve this, I post this question and then figure it out 20 minutes later.
The problem was I had this at the top of my build file:
<property file="build_info.properties"/>
I guess it was due to scoping and that properties are immutable thus I was never able to update the value. Removing that line and then adding the following got it working perfectly:
<target name="injectVersion">
<property file="build_info.properties"/>
<replaceregexp file="${referer}" match="#\(#\).*#" replace="#(#)${build.major.number}.${build.minor.number}.${build.revision.number})#" />
</target>
Why not just use <buildnumber/>?
Project used to increment build number in build.properties file
file parameters:
version.number=
build.number=
if changes version.number then build.number starts from 1
====================================================================== -->
<property name="versionFileName" value="build.properties" />
<property file="${versionFileName}" />
<property name="currentVersion" value="0.1.37"/>
<target name="calculate.version.build">
<script language="javascript">
<![CDATA[
var currentVersion = project.getProperty("currentVersion");
var oldVersion = project.getProperty("version.number");
var buildNumber = project.getProperty("build.number");
if (!currentVersion.equals(oldVersion)){
project.setProperty("currentBuild", 1);
} else {
var newBuildNumber = ++buildNumber;
project.setProperty("currentBuild", newBuildNumber);
}
]]>
</script>
</target>
<target name="update.version.build" depends="calculate.version.build">
<propertyfile file="${versionFileName}">
<entry key="build.number" type="int" operation="=" value="${currentBuild}" />
<entry key="version.number" type="string" operation="=" value="${currentVersion}" />
</propertyfile>
<echo message="New version: ${currentVersion}.${currentBuild}" />
</target>

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