This document outlines how the University of Western Ontario's mSub has been organized. You can find our mSub at


Western's implementation of Sakai

Western's implementation of Sakai is called OWL. At the root of our mSub we have a directory called "owl", and underneath that we have "trunk", "branches", and "tags", like so:

The trunk, branches, and tags are essentially "virtual". There is no actual code in these directories, only references in a .externals file to other areas of the repository. A .externals file looks something like this (many lines omitted):


In the example above, the file is telling subversion that the code for the access tool is actually located at The same goes for the other tools.

Setting up the trunk

To set up our trunk, we first created a "trunk" directory in the mSub, then copied in the contents of, on which our trunk was based (we could have also based it on a tag instead). Now it would look like this:

To turn this from a vanilla Sakai branch into the OWL trunk, we first had to modify the .externals file. We'll go into the details of the modifications later on, but for now we'll just outline the process:

1. Checkout the trunk (svn co trunk)
2. Edit the .externals file
3. Commit the changes (svn commit .externals -m "modifying .externals")
4. Confirm the svn:externals property (svn propset svn:externals -F .externals .)

At this point you could run svn update and it would pull down all the code for the various tools in your Sakai implementation.

Western's custom tools

For customized tools, we use a structure where each tool has its own directory at the root, and trunk, branches, and tags directories underneath, like so:

These tools might be custom versions of existing Sakai tools (ie. site-manage), or they might be brand new tools (ie. newTool1).

You've probably guessed by now that our modifications to .externals involve pointing some of the references to our custom tools. Here's how this looks:



Note that the original site-manage reference has been commented out, and our new references have been placed at the bottom.


Since we used the default pom.xml from the 2.8.x branch, it doesn't know about newTool1. We added a <module> line for it under the "full" profile.

Now that the pom.xml is correct, we can build the trunk:

1. Pull down the tool sources if you don't have them yet (svn update or svn co)
2. cd master
3. mvn clean install
4. cd ..
5. mvn clean install

Full structure

Here is how the full mSub structure might look once we have some tags: