Checking a file out (TFS) for a pre-build action

Question

I've added a pre-build action for an ASP.NET web control (server control) project, that runs jsmin.exe on a set of Javascript files. These output files are part of the source control tree and are embedded into the assembly.

The problem is when the pre-build runs, jsmin can't write the file as it's readonly. Is it possible to check the file out before hand? Or am I forced to set the file's attributes in the command line.

Any improved solution to the problem is welcome.

Update One small issue with Mehmet's answer -you need to prepend the VS directory:

"$(DevEnvDir)tf" checkout /lock:none "$(ProjectDir)myfile" 

Answer 1

If you're using Team Foundation Server, you can use team foundation command line utility (tf.exe) to check out the file(s) during pre-build and then check them back in during post-build. If you're using something else for source control, you can check if they have a command line tool like tf.exe.

Answer 2

If you do not want to check the files in as part of the build (which you normally wouldn't for this sort of thing) then I would simply set the attributes of the .js files before running jsmin on them. The easiest way of setting the files read-writeable is to use the the Attrib task provided by the MSBuild community extensions. The same community extensions also provide a JSCompress task for easily calling JSMin from MSBuild.

Therefore you'd have something like the following (not tested):

<Import Project="$(MSBuildExtensionsPath)\MSBuildCommunityTasks\MSBuild.Community.Tasks.Targets" />

<!-- rest of TFSBuild.proj file -->

<Target Name="AfterGet">    
  <Message Text="Compressing Javascript files under &quot;$(SolutionRoot)&quot;." />   
  <CreateItem Include="$(SolutionRoot)\**\*.js">
    <Output TaskParameter="Include" ItemName="JsFiles"/>
  </CreateItem>
  <Attrib Files="@(JsFiles)" ReadOnly="false"/>
  <JSCompress Files="@(JsFiles)" />
</Target>

Note that by modifying the files after getting them may well cause issues if you tried to move to an incremental build.