GraphMLReaderWriter

Class library for

• Serialization of objects into graphML files and,
• Deserialization graphML files back into objects.

The respective NuGet package can be found on https://github.com/budul100/GraphMLReaderWriter.

Writing example

To write a graphML file there must be a graph containing nodes and edges. The nodes are linked by the edges.

internal class Node
{
    #region Public Properties

    [GraphMLReaderWriter.Attributes.Id]
    [GraphMLReaderWriter.Attributes.Data]
    public string Name { get; set; }

    #endregion Public Properties
}

internal class Edge
{
    #region Public Properties

    [GraphMLReaderWriter.Attributes.Source]
    public Node From { get; set; }

    [GraphMLReaderWriter.Attributes.Target]
    public Node To { get; set; }

    #endregion Public Properties
}

internal class Graph
{
    #region Public Properties

    [GraphMLReaderWriter.Attributes.Edges]
    public Edge[] Edges { get; set; }

    [GraphMLReaderWriter.Attributes.Nodes]
    public Node[] Nodes { get; set; }

    #endregion Public Properties
}

Nodes must have a string property marked with the Id attribute. The Data attribute of nodes marks all properties which are used to cover data content in the resulting graphML data.

Edges must have one node property marked with a Source attribute, this node represents the start of the edge. And edges must have one node property marked with a Target attribute, this node represents the end of the edge.

Nodes and edges must be combined in a joint class. The collection of nodes in this class must be marked with an Nodes attribute. The collection of edges in this class must be marked with an Edges attribute.

The graph can be serialized by using the Writer.

var nodeA = new Node
{
    Name = "a",
};

var nodeB = new Node
{
    Name = "b",
};

var nodeC = new Node
{
    Name = "c",
};

var edgeAB = new Edge
{
    From = nodeA,
    To = nodeB,
};

var edgeAC = new Edge
{
    From = nodeA,
    To = nodeC,
};

var graph = new Graph
{
    Edges = new Edge[] { edgeAB, edgeAC },
    Nodes = new Node[] { nodeA, nodeB, nodeC },
};

var writer = new Writer<Graph>();

writer.Save(
    input: graph,
    path: path);

The example above creates the following graphML file.

<?xml version="1.0" encoding="utf-8"?>
<graphml xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://graphml.graphdrawing.org/xmlns">
  <key id="Key-0" for="node" attr.name="Name" attr.type="string" />
  <key id="Key-1" for="graph" attr.name="Name" attr.type="string" />
  <graph id="Graph-0" edgedefault="directed">
    <node id="a">
      <data key="Key-0">a</data>
    </node>
    <node id="b">
      <data key="Key-0">b</data>
    </node>
    <node id="c">
      <data key="Key-0">c</data>
    </node>
    <edge id="Edge-1" source="a" target="b" />
    <edge id="Edge-2" source="a" target="c" />
  </graph>
</graphml>

Reading example

An existing graphML file can be deserialized by using the Reader.

var reader = new Reader<Graph>();

var graph = reader.Load(
    path: path);