Tutorial 2: Loading hierarchical data

This tutorial shows how to load hierarchical data recursively from XML and create diagram items corresponding to the hierarchy. It assumes you have already integrated the diagram library into your project, as shown in Getting Started guide.

1. Right-click the project in Solution Explorer and choose Add -> New Item from the context menu. Create a new XML file called SampleTree.xml and add to it content in the following form:

XML

<?xml version="1.0" encoding="utf-8" ?> 
<Project>
    <Activity Name="Activity 1">
        <Activity  Name="sub-activity 1">
            <Activity  Name="sub-activity 1-1" />
            <Activity  Name="sub-activity 1-2" />
        </Activity>
        <Activity  Name="sub-activity 2">
            <Activity  Name="sub-activity 2-1" />
            <Activity  Name="sub-activity 2-2" />
            <Activity  Name="sub-activity 2-3" />
        </Activity>
        <Activity  Name="sub-activity 3">
            <Activity  Name="sub-activity 3-1" />
            <Activity  Name="sub-activity 3-2" />
        </Activity>
    </Activity>
    <Activity Name="Activity 2">
        <Activity  Name="sub-activity 1">
            <Activity  Name="sub-activity 1-1" />
            <Activity  Name="sub-activity 1-2" />
            <Activity  Name="sub-activity 1-3" />
        </Activity>
        <Activity  Name="sub-activity 2">
            <Activity  Name="sub-activity 2-1" />
            <Activity  Name="sub-activity 2-2" />
        </Activity>
    </Activity>
    <Activity Name="Activity 3">
        <Activity  Name="sub-activity 1">
            <Activity  Name="sub-activity 1-1" />
            <Activity  Name="sub-activity 1-2" />
            <Activity  Name="sub-activity 1-3" />
            <Activity  Name="sub-activity 1-4" />
        </Activity>
        <Activity  Name="sub-activity 2" />
        <Activity  Name="sub-activity 3">
            <Activity  Name="sub-activity 3-1" />
            <Activity  Name="sub-activity 3-2" />
        </Activity>
    </Activity>
</Project>

2. Set the file's "Build Action" property to "Embedded resource".

3. Add the following member to the page class to hold the default node size.

C#

Rect bounds = new Rect(0, 0, 24, 6);

4. Create the tree root node, and call the CreateChildren method, which builds the tree recursively.

C#

var root = diagram.Factory.CreateShapeNode(nodeBounds);
root.Text = "Project";

// Load the graph xml
var assembly = typeof(App).GetTypeInfo().Assembly;
Stream stream = assembly.GetManifestResourceStream("Tutorial2.SampleTree.xml");

string text;
using (var reader = new StreamReader(stream))
{
    text = reader.ReadToEnd();
}

XDocument document = XDocument.Parse(text);
CreateChildren(root, document.Root);

5. Define CreateChildren as follows. It takes as parameters the parent DiagramNode and parent XML element, iterates the child XML elements to build the next level of the hierarchy, and creates corresponding diagram items by calling CreateShapeNode and CreateDiagramLink.

C#

void CreateChildren(DiagramNode parentDiagNode, XElement parentXmlElement)
{
    var activities = parentXmlNode.Elements();
    foreach (var activity in activities)
    {
        if (activity.Name == "Activity")
        {
            var node = diagram.Factory.CreateShapeNode(bounds);
            node.Text = activity.Attribute(XName.Get("Name")).Value;
            diagram.Factory.CreateDiagramLink(parentDiagNode, node);
            CreateChildren(node, activity);
        }
    }
}

6. Use TreeLayout to arrange the diagram. Add the following code to the end of the Loaded handler.

C#

var layout = new TreeLayout();
layout.Type = TreeLayoutType.Cascading;
layout.Direction = TreeLayoutDirections.LeftToRight;
layout.LinkStyle = TreeLayoutLinkType.Cascading2;
layout.NodeDistance = 3;
layout.LevelDistance = -8;
layout.Arrange(diagram);

7. Build and run the project. If everything is fine, you should see this representation of the hierarchy:

Complete sample project is available in Samples/Tutorial2 folder from distribution.