Best Practices for Project Feature Sub-Modules with Mercurial and Eclipse?

Question

I have a couple of ANT projects for several different clients; the directory structure I have for my projects looks like this:

L___standard_workspace
    L___.hg
    L___validation_commons-sub-proj  <- JS Library/Module
    |   L___java
    |   |   L___jar
    |   L___old_stuff
    |   L___src
    |   |   L___css
    |   |   L___js
    |   |       L___validation_commons
    |   L___src-test
    |       L___js
    L___v_file_attachment-sub-proj  <- JS Library/Module
    |   L___java
    |   |   L___jar
    |   L___src
    |   |   L___css
    |   |   L___js
    |   L___src-test
    |       L___js
    L___z_business_logic-sub-proj  <- JS Library/Module
    |   L___java
    |   |   L___jar
    |   L___src
    |       L___css
    |       L___js
    L____master-proj               <- Master web-deployment module where js libraries are compiled to.
        L___docs
        L___java
        |   L___jar
        |   L___src
        |       L___AntTasks
        |           L___build
        |           |   L___classes
        |           |       L___com
        |           |           L___company
        |           L___dist
        |           L___nbproject
        |           |   L___private
        |           L___src
        |               L___com
        |                   L___company
        L___remoteConfig
        L___src
        |   L___css
        |   |   L___blueprint
        |   |   |   L___plugins
        |   |   |   |   L___buttons
        |   |   |   |   |   L___icons
        |   |   |   |   L___fancy-type
        |   |   |   |   L___link-icons
        |   |   |   |   |   L___icons
        |   |   |   |   L___rtl
        |   |   |   L___src
        |   |   L___jsmvc
        |   L___img
        |   |   L___background-shadows
        |   |   L___banners
        |   |   L___menu
        |   L___js
        |   |   L___approve
        |   |   L___cart
        |   |   L___confirm
        |   |   L___history
        |   |   L___jsmvc
        |   |   L___mixed
        |   |   L___office
        |   L___stylesheets
        |   L___swf
        L___src-standard

Within the working copy the modules compile the sub-project into a single Javascript file that is placed in the Javascript directory of the master project.

For example, the directories:

• validation_commons-sub-proj
• v_file_attachment-sub-proj
• z_business_logic-sub-proj

...all are combined and minified (sort of like compiled) into a different Javascript filename in the _master-proj/js directory; and in the final step the _master-proj is compiled to be deployed to the server.

Now in regards to the way I'd like to set this up with hg, what I'd like to be able to do is clone the master project and its sub-projects from their own base-line repositories into a client's working-copy, so that modules can be added (using hg) to a particular customer's working copy.

Additionally however, when I do make some changes to/fix bugs in one customer's working copy, I would like to be able to optionally push the changes/bug fixes back to the master project/sub-project's base-line repository, for purposes of eventually pulling the changes/fixes into other customer's working copies that might contain the same bugs that need to be fixed.

In this way I will be able to utilize the same bug fixes across different clients.

However...I am uncertain of the best way to do this using hg and Eclipse.

I read here that you can use hg's Convert Extension to split a sub-directory into a separate project using the --filemap option.

However, I'm still a little bit confused as to if it would be better to use the Convert Extension or if it would be better to just house each of the modules in their own repository and check them out into a single workspace for each client.

Answer 1

Yep, it looks like subrepos are what you are looking for, but I think maybe that is the right answer for the wrong question and I strongly suspect that you'll run into similar issues that occur when using svn:externals

Instead I would recommend that you "publish" your combined and minified JS files to an artefact repository and use a dependency manager such as Ivy to pull specific versions of your artefacts into your master project. This approach give you far greater control over the sub-project versions your master project uses.

If you need to make bug fixes to a sub-project for a particular client, you can just make the fixes on the mainline for that sub-project, publish a new version (ideally via an automated build pipeline) and update their master project to use the new version. Oh, you wanted to test the new version with the their master project before publishing? In that case, before you push your fix, combine and minify your sub-project locally, publish it to a local repository and have the client's master project pick up that version for your testing.