discussion about conditional structures

[jamin]

Hi all,

I suppose that there have been a lot of discussion about conditional structures, but I would like to open another one.
For now, I notice two solutions :

>> solution 1 : ant approach, using if and unless parameters.

<target name="todo" depends="ok,ko"/>
<target name="ok" if="my-property-is-set"/>
<target name="ko" unless="my-property-is-NOT-set"/>

Disadvantages :
- not as simple as it should be
- property evaluation is not possible (or I don't know how to do this)

>> solution 2 : ant-contrib

<if>
    <equals arg1="..." arg2="..."/>
</if>

Disadvantages :
- verbose solution
- project still maintain ?
- solution not integrated in the ant project

>> solution 3
I would like to discuss about another solution, based upon <antcall> et <condition> tasks.

<antcall target="todo">
    <condition>
        <equals arg1="${val1}" arg2="${val2}"/>
    </condition>
</antcall>

Target would be executed if condition succeeded.

Advantages :
+ use an existing task : <antcall> by adding a nested element
=> quiet easy to implement (see attached file)
+ use all <condition> possibilities

What do you think about this idea ?

Best regards,
Benjamin

package net.sourceforge.ant4hg.contrib;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.taskdefs.CallTarget;
import org.apache.tools.ant.taskdefs.condition.Condition;
import org.apache.tools.ant.taskdefs.condition.ConditionBase;

public class CallTarget2 extends CallTarget {

    // //////////////////////////////////////////////
    // INNER CLASS
    // //////////////////////////////////////////////
    /**
     * @see org.apache.tools.ant.taskdefs.Exit
     */
    private static class NestedCondition extends ConditionBase implements Condition {
        public boolean eval() {
            if (countConditions() != 1) {
                throw new BuildException("A single nested condition is required.");
            }
            return ((Condition) (getConditions().nextElement())).eval();
        }
    }

    // //////////////////////////////////////////////
    // ATTRIBUTES
    // //////////////////////////////////////////////
    /**
     * @see org.apache.tools.ant.taskdefs.Exit
     */
    private NestedCondition nestedCondition;

    /**
     * @see org.apache.tools.ant.taskdefs.Exit
     */
    public ConditionBase createCondition() {
        if (nestedCondition != null) {
            throw new BuildException("Only one nested condition is allowed.");
        }
        nestedCondition = new NestedCondition();
        return nestedCondition;
    }

    // //////////////////////////////////////////////
    // CONSTRUCTORS
    // //////////////////////////////////////////////
    public CallTarget2() {
        super();
        setTaskName("antcall");
    }

    // //////////////////////////////////////////////
    // OVERRIDEN METHODS
    // //////////////////////////////////////////////
    public void execute() throws BuildException {
        if (!nestedCondition.eval()) {
            return;
        }
        super.execute();
    }

}



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[Jeffrey E Care]

We've already discussed various schemes for expanding the conditional execution of targets, most recently by allowing conditions as top-level children of targets. Check the archives.

____________________________________________________________________________________________
Jeffrey E. (Jeff) Care	carej@...
IBM WebSphere Application Server	WAS Release Engineering

Benjamin de Dardel <benjamin.dedardel@...> wrote on 06/22/2009 05:54:32 PM:

> [image removed]
>
> discussion about conditional structures
>
> Benjamin de Dardel
>
> to:
>
> Ant Developers List
>
> 06/22/2009 05:55 PM
>
> Please respond to "Ant Developers List"
>
> Hi all,
>
> I suppose that there have been a lot of discussion about conditional
> structures, but I would like to open another one.
> For now, I notice two solutions :
>
> >> solution 1 : ant approach, using if and unless parameters.
> <target name="todo" depends="ok,ko"/>
> <target name="ok" if="my-property-is-set"/>
> <target name="ko" unless="my-property-is-NOT-set"/>
> Disadvantages :
> - not as simple as it should be
> - property evaluation is not possible (or I don't know how to do this)
>
> >> solution 2 : ant-contrib
> <if>
>     <equals arg1="..." arg2="..."/>
> </if>
> Disadvantages :
> - verbose solution
> - project still maintain ?
> - solution not integrated in the ant project
>
> >> solution 3
> I would like to discuss about another solution, based upon <antcall>
> et <condition> tasks.
> <antcall target="todo">
>     <condition>
>         <equals arg1="${val1}" arg2="${val2}"/>
>     </condition>
> </antcall>
> Target would be executed if condition succeeded.
>
> Advantages :
> + use an existing task : <antcall> by adding a nested element
> => quiet easy to implement (see attached file)
> + use all <condition> possibilities
>
> What do you think about this idea ?
>
> Best regards,
> Benjaminpackage net.sourceforge.ant4hg.contrib;
>
> import org.apache.tools.ant.BuildException;
> import org.apache.tools.ant.taskdefs.CallTarget;
> import org.apache.tools.ant.taskdefs.condition.Condition;
> import org.apache.tools.ant.taskdefs.condition.ConditionBase;
>
> public class CallTarget2 extends CallTarget {
>
>     // //////////////////////////////////////////////
>     // INNER CLASS
>     // //////////////////////////////////////////////
>     /**
>      * @see org.apache.tools.ant.taskdefs.Exit
>      */
>     private static class NestedCondition extends ConditionBase
> implements Condition {
>         public boolean eval() {
>             if (countConditions() != 1) {
>                 throw new BuildException("A single nested condition
> is required.");
>             }
>             return ((Condition) (getConditions().nextElement())).eval();
>         }
>     }
>
>     // //////////////////////////////////////////////
>     // ATTRIBUTES
>     // //////////////////////////////////////////////
>     /**
>      * @see org.apache.tools.ant.taskdefs.Exit
>      */
>     private NestedCondition nestedCondition;
>
>     /**
>      * @see org.apache.tools.ant.taskdefs.Exit
>      */
>     public ConditionBase createCondition() {
>         if (nestedCondition != null) {
>             throw new BuildException("Only one nested condition is allowed.");
>         }
>         nestedCondition = new NestedCondition();
>         return nestedCondition;
>     }
>
>     // //////////////////////////////////////////////
>     // CONSTRUCTORS
>     // //////////////////////////////////////////////
>     public CallTarget2() {
>         super();
>         setTaskName("antcall");
>     }
>
>     // //////////////////////////////////////////////
>     // OVERRIDEN METHODS
>     // //////////////////////////////////////////////
>     public void execute() throws BuildException {
>         if (!nestedCondition.eval()) {
>             return;
>         }
>         super.execute();
>     }
>
> }
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@...
> For additional commands, e-mail: dev-help@...

[jamin]

 >> using condition in target
Ok, I found the topic you're talking about :
http://marc.info/?l=ant-dev&m=124052209931008&w=2

Append <condition> task as the first element of <target> task would be
really nice.
Do you know if it's implemented ? or planned to be implemented ?

 >> using return task
By going in this way, I think that using a <return> task would be more
flexible  :
- may be used wherever in the <target> task
- may be implemented in other tasks (<macrodef>)

For example :

    /<target name="test-return"> /
    /    <echo message="test-return : begin" /> /
    /    <return message="return from target"> /
    /        <condition> /
    /            <equals arg1="Y" arg2="Y" /> /
    /        </condition> /
    /    </return> /
    /    <echo message="test-return : end" /> /
    /</target> /

     > ant -f test.xml test-return
    Buildfile: test.xml
    test-return:
        [echo] test-return : begin
      [return] return from target
    BUILD SUCCESSFUL
    Total time: 0 seconds

To implement this example :
- I create a /Return/ class from the /Exit/ one, it's quiet the same
I just /throw new ReturnException(this.message)/ at the end

- I catch the Exception in the /Target/ class

    /[...]
    } catch (ReturnException e) { /
    /    Echo echo = new Echo(); /
    /    echo.setProject(getProject()); /
    /    echo.setTaskName("return"); /
    /    echo.setMessage(e.getMessage().substring("ReturnException:
    ".length(),e.getMessage().length()).trim()); /
    /    echo.execute(); /
    /} finally { /
    /    localProperties.exitScope(); /
    /}/

I can work on this task (implementation, unit tests, doc...), if this
idea is approved.

Regards,
Benjamin


Jeffrey E Care a écrit :

>
> We've already discussed various schemes for expanding the conditional
> execution of targets, most recently by allowing conditions as
> top-level children of targets. Check the archives.
> ____________________________________________________________________________________________
>
> Jeffrey E. (Jeff) Care
> _carej@... <mailto:carej@...>
> IBM WebSphere Application Server
> WAS Release Engineering
>
>
> WebSphere Mosiac
> WebSphere Brandmark
>
>
>
>
> Benjamin de Dardel <benjamin.dedardel@...> wrote on 06/22/2009
> 05:54:32 PM:
>
> > [image removed]
> >
> > discussion about conditional structures
> >
> > Benjamin de Dardel
> >
> > to:
> >
> > Ant Developers List
> >
> > 06/22/2009 05:55 PM
> >
> > Please respond to "Ant Developers List"
> >
> > Hi all,
> >
> > I suppose that there have been a lot of discussion about conditional
> > structures, but I would like to open another one.
> > For now, I notice two solutions :
> >
> > >> solution 1 : ant approach, using if and unless parameters.
> > <target name="todo" depends="ok,ko"/>
> > <target name="ok" if="my-property-is-set"/>
> > <target name="ko" unless="my-property-is-NOT-set"/>
> > Disadvantages :
> > - not as simple as it should be
> > - property evaluation is not possible (or I don't know how to do this)
> >
> > >> solution 2 : ant-contrib
> > <if>
> >     <equals arg1="..." arg2="..."/>
> > </if>
> > Disadvantages :
> > - verbose solution
> > - project still maintain ?
> > - solution not integrated in the ant project
> >
> > >> solution 3
> > I would like to discuss about another solution, based upon <antcall>
> > et <condition> tasks.
> > <antcall target="todo">
> >     <condition>
> >         <equals arg1="${val1}" arg2="${val2}"/>
> >     </condition>
> > </antcall>
> > Target would be executed if condition succeeded.
> >
> > Advantages :
> > + use an existing task : <antcall> by adding a nested element
> > => quiet easy to implement (see attached file)
> > + use all <condition> possibilities
> >
> > What do you think about this idea ?
> >
> > Best regards,
> > Benjaminpackage net.sourceforge.ant4hg.contrib;
> >
> > import org.apache.tools.ant.BuildException;
> > import org.apache.tools.ant.taskdefs.CallTarget;
> > import org.apache.tools.ant.taskdefs.condition.Condition;
> > import org.apache.tools.ant.taskdefs.condition.ConditionBase;
> >
> > public class CallTarget2 extends CallTarget {
> >
> >     // //////////////////////////////////////////////
> >     // INNER CLASS
> >     // //////////////////////////////////////////////
> >     /**
> >      * @see org.apache.tools.ant.taskdefs.Exit
> >      */
> >     private static class NestedCondition extends ConditionBase
> > implements Condition {
> >         public boolean eval() {
> >             if (countConditions() != 1) {
> >                 throw new BuildException("A single nested condition
> > is required.");
> >             }
> >             return ((Condition) (getConditions().nextElement())).eval();
> >         }
> >     }
> >
> >     // //////////////////////////////////////////////
> >     // ATTRIBUTES
> >     // //////////////////////////////////////////////
> >     /**
> >      * @see org.apache.tools.ant.taskdefs.Exit
> >      */
> >     private NestedCondition nestedCondition;
> >
> >     /**
> >      * @see org.apache.tools.ant.taskdefs.Exit
> >      */
> >     public ConditionBase createCondition() {
> >         if (nestedCondition != null) {
> >             throw new BuildException("Only one nested condition is
> allowed.");
> >         }
> >         nestedCondition = new NestedCondition();
> >         return nestedCondition;
> >     }
> >
> >     // //////////////////////////////////////////////
> >     // CONSTRUCTORS
> >     // //////////////////////////////////////////////
> >     public CallTarget2() {
> >         super();
> >         setTaskName("antcall");
> >     }
> >
> >     // //////////////////////////////////////////////
> >     // OVERRIDEN METHODS
> >     // //////////////////////////////////////////////
> >     public void execute() throws BuildException {
> >         if (!nestedCondition.eval()) {
> >             return;
> >         }
> >         super.execute();
> >     }
> >
> > }
> >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: dev-unsubscribe@...
> > For additional commands, e-mail: dev-help@...