Question

I am currently using YUI to compress JavaScript files via Ant:

<apply executable="java" parallel="false">
    <fileset dir="." includes="${build.web.dir}/js/*.js"/>
    <arg line="-jar"/>
    <arg path="yuicompressor-2.4.7.jar"/>           
    <srcfile/>
    <arg line="-o"/>
    <mapper type="glob" from="*.js" to="*-min.js"/>
    <targetfile/>      
</apply>

However the newly created *-min.js files now have newer “Last Modified” dates. This becomes a problem when I rollout the files using RSYNC which compares the last modified date to determine whether or not the file should be updated.

Ideally I would like to preserve the last modified date so the rollout doesn’t update all the files unnecessarily and also overwriting newer files on the server (It has happened before).

Answer 1

Thanks to @martin-clayton I was able to use the Touch Task to restore the newly created minified files to their original Last Modified dates.

The following is a parameterised ant call allowing both CSS and JS files to be easily minified:

<target name="minify-filetype" >
    <echo>Minimise all ${filetype} files</echo>
    <apply executable="java" parallel="false">
        <fileset dir="." includes="${build.web.dir}/${filetype}/*.${filetype}"/>
        <arg line="-jar"/>
        <arg path="../../../etc/ant/trunk/lib/yuicompressor-2.4.7.jar"/>            
        <srcfile/>
        <arg line="-o"/>
        <mapper type="glob" from="*.${filetype}" to="*-min.${filetype}"/>
        <targetfile/>      
    </apply>

    <echo>Convert minified files back to original Last Modified dates</echo>
    <touch>
        <fileset dir="." includes="${build.web.dir}/${filetype}/*.${filetype}"
                         excludes="${build.web.dir}/${filetype}/*-min.${filetype}"/>
        <mapper type="glob" from="*.${filetype}" to="*-min.${filetype}"/>
    </touch>

    <!-- moving *-min.js and creating *.js files (overwriting orginal and deleting *-min) -->
    <move todir="${build.web.dir}/${filetype}/" overwrite="true" preservelastmodified="true">
        <fileset dir="${build.web.dir}/${filetype}/" />
        <mapper type="glob" from="*-min.${filetype}" to="*.${filetype}"/>
    </move>
</target>