T4 template to generate DGML org charts from simple DSL

OrgChart.tree

Joe
    Jill
        Bill
        Bert
        David
    John
        Bob

OrgChart.tt

<#/*
Org Chart generator using DGML, by David Ebbo (@davidebbo)

To use this template, add it to a VS project, and create a .tree file with the same name (e.g. OrgChart.tree).
That file uses a simple DSL to define the org hierarchy, e.g.

Joe
    Jill
        Bill
        Bert
        David
    John
        Bob

When you run the tt template (by saving it or choosing 'Run Custom Tool'), it generates an OrgChart.dgml file that
you can them open in VS to view as a graphical org chart.

*/#><#@ template debug="false" hostspecific="true" language="C#" 
#><#@ output extension=".dgml" 
#><#@ assembly name="System.Core" 
#><#@ import namespace="System.IO" 
#><#@ import namespace="System.Linq"
#><?xml version="1.0" encoding="utf-8"?>
<DirectedGraph xmlns="http://schemas.microsoft.com/vs/2009/dgml">
  <Links>
<# RenderLinks(); #>
  </Links>
</DirectedGraph>

<#+ 
int Index;
UserEntry[] Users;

void RenderLinks() {
    string inputFile = Path.ChangeExtension(Host.TemplateFile, ".tree");
    Users = File.ReadAllLines(inputFile).Select(line => new UserEntry(line)).ToArray();

    ProcessChildren();
}

void ProcessChildren(UserEntry parentUser = null) {
    for (; ; ) {
        if (Index >= Users.Length) break;

        var currentEntry = Users[Index];
        if (parentUser != null && currentEntry.Indent <= parentUser.Indent) break;
        Index++;

        if (parentUser != null) {
#>
    <Link Source="<#= parentUser.Name #>" Target="<#= currentEntry.Name #>" />
<#+
        }

        ProcessChildren(currentEntry);
    }
}

class UserEntry {
    public UserEntry(string line) {
        for (; Indent < line.Length && line[Indent] == ' '; Indent++) { }
        Name = line.Trim();
    }

    public int Indent { get; set; }
    public string Name { get; set; }
}
#>