L0 = <http://www.simantics.org/Layer0-1.1>
DIA = <http://www.simantics.org/Diagram-2.2>
STR = <http://www.simantics.org/Structural-1.2>
MOD = <http://www.simantics.org/Modeling-1.2>
VP = <http://www.simantics.org/Viewpoint-1.2>
IMAGE = <http://www.simantics.org/Image2-1.2>
SEL = <http://www.simantics.org/SelectionView-1.2>
SEL_UI = <http://www.simantics.org/SelectionViewUI-1.1>
G2D = <http://www.simantics.org/G2D-1.1>
DN = <http://www.simantics.org/DistrictNetwork-1.0>

DN.Groups : L0.Library

DN.DistrictNodeGroup <T DIA.TypeGroup
    >-- DN.DistrictNodeGroup.hasComponentTypeName ==> "String" <R L0.HasProperty

DN.Groups.VertexGroup : DIA.TypeGroup
    DIA.TypeGroup.HasType DN.Vertex
DN.Groups.EdgeGroup : DIA.TypeGroup
    DIA.TypeGroup.HasType DN.Edge

DN.ElementColoringStyle : DIA.Style
DN.VertexSizeStyle : DIA.Style
DN.EdgeThicknessStyle : DIA.Style
DN.HideStyle : DIA.Style
DN.VertexSymbolStyle : DIA.Style
DN.ConnectionLineStyle : DIA.Style

// Function for dynamic selection of symbols for a vertex
// The input of the function is a DN.Vertex
// The output of the function should be SVG
DN.HasSymbolFunction <R L0.HasProperty
    <-- DIA.ProfileEntry
    --> L0.Value
    ==> "Resource -> <ReadGraph> Maybe String"