Connector in Blazor Diagram Component

8 Jun 202324 minutes to read

Connectors are objects used to create link between two points, nodes or ports to represent the relationships between them.

Create connector

Connector can be created by defining the source and target point of the connector. The path to be drawn can be defined with a collection of segments.

To create and customize the connectors easily in the Blazor Diagram component, refer to the below video link.

How to add connectors through connectors collection

The SourcePoint and TargetPoint properties of connector allow you to define the endpoints of a connector.

The following code example illustrates how to add a connector through connector collection,

@using Syncfusion.Blazor.Diagram

<SfDiagramComponent Width="1000px" Height="500px" Connectors="@connectors">
    <SnapSettings Constraints="@snapConstraints"></SnapSettings>
</SfDiagramComponent>

@code
{
    SnapConstraints snapConstraints = SnapConstraints.None;
    //Defines diagram's connector collection.
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();

    protected override void OnInitialized()
    {
        Connector Connector = new Connector()
        {
            ID = "connector1",
            // Set the source and target point of the connector.
            SourcePoint = new DiagramPoint() { X = 100, Y = 100 },
            TargetPoint = new DiagramPoint() { X = 200, Y = 200 },
            // Type of the connector segments.
            Type = ConnectorSegmentType.Straight
        };
        connectors.Add(Connector);
    }
}

You can download a complete working sample from GitHub

Blazor Diagram Connector

NOTE

ID for each connector should be unique and so it is further used to find the connector at runtime and do any customization.

Note: Connectors’ Id should not start with numbers or special characters and should not contain special characters such as underscore(_) or space.

How to add connectors at runtime

You can add a connector at runtime by adding connector to the connectors collection in the Diagram component. The following code explains how to add connectors at runtime.

@using Syncfusion.Blazor.Diagram
@using Syncfusion.Blazor.Buttons


<SfButton Content="Add Connector" OnClick="@AddConnector" />
<SfDiagramComponent Width="1000px" Height="500px" Connectors="@connectors"></SfDiagramComponent>

@code
{

    //Defines diagram's connector collection.
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();

    protected override void OnInitialized()
    {
        Connector Connector = new Connector()
        { 
            ID = "connector1",
            SourcePoint = new DiagramPoint() { X = 100, Y = 100 },
            TargetPoint = new DiagramPoint() { X = 200, Y = 200 },
            Type = ConnectorSegmentType.Straight
        };
        connectors.Add(Connector);
    }

    public void AddConnector()
    {
        Connector NewConnector = new Connector()
        { 
            ID = "connector2",
            SourcePoint = new DiagramPoint() { X = 300, Y = 300 },
            TargetPoint = new DiagramPoint() { X = 400, Y = 400 },
            Type = ConnectorSegmentType.Straight
        };
        //Add the connector at the run time.
        connectors.Add(NewConnector);
    }
}

You can download a complete working sample from GitHub

How to clone the connector at runtime

Clone is a virtual method of the connector that is used to create a copy of a diagram object. After cloning, we need to set the ID for cloned connectors. The following code demonstrates how to clone the connector during runtime.

@using Syncfusion.Blazor.Diagram
@using System.Collections.ObjectModel
@using Syncfusion.Blazor.Buttons
@inject IJSRuntime js

<SfButton Content="Clone Connector" OnClick="@CloneConnector" />
<SfDiagramComponent @ref="diagram" Width="50%" Height="500px" @bind-Connectors="@Connectors"></SfDiagramComponent>

@functions
{

    SfDiagramComponent diagram;
    public DiagramObjectCollection<Connector> Connectors = new DiagramObjectCollection<Connector>();
    protected override void OnInitialized()
    {
        Connector connector1 = new Connector() { ID = "connector1", SourcePoint = new DiagramPoint() { X = 100, Y = 10 }, TargetPoint = new DiagramPoint() { X = 200, Y = 100 }, Type = ConnectorSegmentType.Straight };
        Connectors.Add(connector1);
    }
    public async Task CloneConnector()
    {
        Connector connector = Connectors[0].Clone() as Connector;
        connector.ID = RandomId();
        connector.SourcePoint = new DiagramPoint { X = 100, Y = 100 };
        connector.TargetPoint = new DiagramPoint { X = 200, Y = 100 };
        await diagram.AddDiagramElements(new DiagramObjectCollection<NodeBase>() { connector });

    }
    internal string RandomId()
    {
        Random random = new Random();
        const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
#pragma warning disable CA5394 // Do not use insecure randomness
        return new string(Enumerable.Repeat(chars, 5)
          .Select(s => s[random.Next(s.Length)]).ToArray());
#pragma warning restore CA5394 // Do not use insecure randomness
    }

}

You can download a complete working sample from GitHub
Clonning Node

How to add connector with annotations at runtime

You can add connector with annotation at runtime in the diagram component by using the AddDiagramElements method.

The following code explains how to add an connector with annotation at runtime by using AddDiagramElements method.

@using Syncfusion.Blazor.Diagram
@using Syncfusion.Blazor.Buttons

<SfButton Content="Add Connector" OnClick="@AddConnector" />
<SfDiagramComponent Width="1000px" Height="500px" Connectors="@connectors"></SfDiagramComponent>

@code
{

    //Defines diagram's connector collection.
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();

    DiagramObjectCollection<NodeBase> NodeCollection = new DiagramObjectCollection<NodeBase>();

    protected override void OnInitialized()
    {
        Connector Connector = new Connector()
        { 
            ID = "connector1",
            SourcePoint = new DiagramPoint() { X = 100, Y = 100 },
            TargetPoint = new DiagramPoint() { X = 200, Y = 200 },
            Type = ConnectorSegmentType.Straight
        };
        connectors.Add(Connector);
    }

    public void AddConnector()
    {
        Connector NewConnector = new Connector()
        { 
            ID = "connector2",
            SourcePoint = new DiagramPoint() { X = 300, Y = 300 },
            TargetPoint = new DiagramPoint() { X = 400, Y = 400 },
            Type = ConnectorSegmentType.Straight,
             Annotations=new DiagramObjectCollection<PathAnnotation>()
            {
                new PathAnnotation()
                {
                    Content="NewAnnotation"
                }
            },
        };
        NodeCollection.Add(NewConnector);
       await Diagram.AddDiagramElements(NodeCollection);
    }
}

How to add connector in Palette

Connectors can be predefined and added to the symbol palette. You can drop those connectors into the diagram when required.

@using Syncfusion.Blazor.Diagram
@using Syncfusion.Blazor.Diagram.SymbolPalette

<div style="width: 200px; float: left">
    <SfSymbolPaletteComponent Height="600px" @ref="@PaletteInstance" Palettes="@Palettes">
    </SfSymbolPaletteComponent>
</div>

<SfDiagramComponent @ref="@DiagramInstance" Width="1000px" Height="500px" Connectors="@connectors"></SfDiagramComponent>

@code
{
    SfSymbolPaletteComponent PaletteInstance;
    SfDiagramComponent DiagramInstance;
    //Defines Symbol palette's PaletteConnector collection.
    DiagramObjectCollection<NodeBase> PaletteConnector = new DiagramObjectCollection<NodeBase>();
    DiagramObjectCollection<Palette> Palettes = new DiagramObjectCollection<Palette>();

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        PaletteInstance.Targets = new DiagramObjectCollection<SfDiagramComponent>() { };
        PaletteInstance.Targets.Add(DiagramInstance);
    }

    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();

    protected override void OnInitialized()
    {
        Connector Connector = new Connector()
        {
            ID = "connector1",
            // Set the source and target point of the connector.
            SourcePoint = new DiagramPoint() { X = 100, Y = 100 },
            TargetPoint = new DiagramPoint() { X = 200, Y = 200 },
            // Type of the connector segments.
            Type = ConnectorSegmentType.Straight
        };
        connectors.Add(Connector);
        PaletteConnector = new DiagramObjectCollection<NodeBase>();
        Connector connector = new Connector
        {
            ID = "Link1",
            Type = ConnectorSegmentType.Straight,
            SourcePoint = new DiagramPoint() { X = 0, Y = 0 },
            TargetPoint = new DiagramPoint() { X = 60, Y = 60 }                                                                                 
        };
        PaletteConnector.Add(connector as NodeBase);
        Connector connector2 = new Connector
        {
            ID = "Link2",
            Type = ConnectorSegmentType.Orthogonal,
            SourcePoint = new DiagramPoint() { X = 0, Y = 0 },
            TargetPoint = new DiagramPoint() { X = 60, Y = 60 },
            TargetDecorator = new DecoratorSettings() { Shape = DecoratorShape.OpenArrow },
            Style = new ShapeStyle() { StrokeWidth =1}
        };
        PaletteConnector.Add(connector2 as NodeBase);
        Connector connector3 = new Connector
        {
            ID = "Link3",
            Type = ConnectorSegmentType.Bezier,
            SourcePoint = new DiagramPoint() { X = 0, Y = 0 },
            TargetPoint = new DiagramPoint() { X = 60, Y = 60 },
            TargetDecorator = new DecoratorSettings() { Shape = DecoratorShape.None },
        };
        PaletteConnector.Add(connector3 as NodeBase);
        Palettes = new DiagramObjectCollection<Palette>()
        {
            new Palette(){ Symbols = PaletteConnector, Title = "Connectors", IsExpanded = true },
        };
    }
}

You can download a complete working sample from GitHub

Connector from Palette in Blazor Diagram

How to draw connectors using drawing object

Connectors can be interactively drawn by clicking and dragging on the diagram surface by using DrawingObject.

Drawing Connector in Blazor Diagram

How to remove connectors at runtime

A connector can be removed from the diagram at runtime by using the Remove method.

The following code shows how to remove a connector at runtime.

@using Syncfusion.Blazor.Diagram
@using Syncfusion.Blazor.Buttons


<SfButton Content="Remove Connector" OnClick="@RemoveConnector" />
<SfDiagramComponent Width="1000px" Height="500px" Connectors="@connectors">
    <SnapSettings Constraints="@snapConstraints"></SnapSettings>
</SfDiagramComponent>
@code {
    //Defines snap consttraints
    SnapConstraints snapConstraints = SnapConstraints.None;
    //Defines diagram's connector collection
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();
    protected override void OnInitialized()
    {
        Connector Connector = new Connector()
            {
                ID = "connector1",
                // Set the source and target point of the connector
                SourcePoint = new DiagramPoint() { X = 100, Y = 100 },
                TargetPoint = new DiagramPoint() { X = 200, Y = 200 },
                TargetDecorator = new DecoratorSettings()
                {
                    Shape = DecoratorShape.Arrow,
                    // Style of the connector segment
                    Style = new ShapeStyle() { Fill = "#6f409f", StrokeColor = "#6f409f", StrokeWidth = 1 }
                },
                Style = new ShapeStyle() { StrokeColor = "#6f409f", StrokeWidth = 1 },
                // Type of the connector
                Type = ConnectorSegmentType.Straight,
            };
        connectors.Add(Connector);
    }
    public void RemoveConnector()
    {
        // Remove connector at runtime
        connectors.Remove(connectors[0]);
    }
}

You can download a complete working sample from GitHub

A connector can be removed from the diagram by using the native RemoveAt method. Refer to the following example that shows how to remove the connector at runtime.

public void RemoveConnector()
{
    connectors.RemoveAt(0);
}

How to update connectors at runtime

You can change any connector’s properties at runtime.

The following code example explains how to change the connector properties.

@using Syncfusion.Blazor.Diagram
@using Syncfusion.Blazor.Buttons


<SfButton Content="Update Connector" OnClick="@UpdateConnector" />
<SfDiagramComponent @ref="Diagram" Width="1000px" Height="500px" Connectors="@connectors">
    <SnapSettings Constraints="@snapConstraints"></SnapSettings>
</SfDiagramComponent>
@code {
    //Reference the diagram
    SfDiagramComponent Diagram;
    //Defines the snap constraints
    SnapConstraints snapConstraints = SnapConstraints.None;
    //Defines diagram's connector collection
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();
    protected override void OnInitialized()
    {
        Connector Connector = new Connector()
            {
                ID = "connector1",
                SourcePoint = new DiagramPoint() { X = 100, Y = 100 },
                TargetPoint = new DiagramPoint() { X = 200, Y = 200 },
                TargetDecorator = new DecoratorSettings() { Shape = DecoratorShape.Arrow, Style = new ShapeStyle() { Fill = "#6f409f", StrokeColor = "#6f409f", StrokeWidth = 1 } },
                Style = new ShapeStyle() { StrokeColor = "#6f409f", StrokeWidth = 1 },
                // Type of the connector
                Type = ConnectorSegmentType.Straight,
            };
        connectors.Add(Connector);
    }
    //Method to update connector at runtime.
    public void UpdateConnector()
    {
        Diagram.BeginUpdate();
        Diagram.Connectors[0].SourcePoint.X = 50;
        Diagram.Connectors[0].SourcePoint.Y = 50;
        Diagram.EndUpdate();
    }
}

You can download a complete working sample from GitHub

NOTE

BeginUpdate and EndUpdate methods allow you to stop the continuous update of control and resume it finally.

Connections

A connectors are used to create a link between two points, nodes or ports to represent the relationships between them.

Connections with nodes

The SourceID and TargetID properties allow to define the nodes to be connected.

The following code example illustrates how to connect two nodes.

@using Syncfusion.Blazor.Diagram

<SfDiagramComponent @ref="Diagram" Width="1000px" Height="500px" Nodes="@nodes" Connectors="@connectors">
</SfDiagramComponent>

@code
{
    SfDiagramComponent Diagram;
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();
    DiagramObjectCollection<Node> nodes = new DiagramObjectCollection<Node>();

    protected override void OnInitialized()
    {
        nodes = new DiagramObjectCollection<Node>()
        {
            new Node() 
            {
                OffsetX = 100,
                OffsetY = 100,
                Height = 50,
                Width = 100,
                ID = "node1",
                Style = new ShapeStyle(){ Fill = "#6495ED", StrokeColor = "#6495ED" },
                Shape = new BasicShape() { Type = NodeShapes.Basic, Shape = NodeBasicShapes.Rectangle }
            },
            new Node()
            {
                OffsetX = 300,
                OffsetY = 300,
                Height = 50,
                Width = 100,
                ID = "node2",
                Style = new ShapeStyle(){ Fill = "#6495ED", StrokeColor = "#6495ED" },
                Shape = new BasicShape() { Type = NodeShapes.Basic, Shape = NodeBasicShapes.Rectangle }
            }
        };
        Connector Connector = new Connector()
        {
            ID = "connector1",
            //Source node id of the connector.
            SourceID = "node1",
            TargetDecorator = new DecoratorSettings()
            {
                Style = new ShapeStyle()
                {
                    Fill = "#6495ED",
                    StrokeColor = "#6495ED",
                }
            },
            //Target node id of the connector.
            TargetID = "node2",
            Style = new ShapeStyle()
            {
                Fill = "#6495ED",
                StrokeColor = "#6495ED",
            },
            // Type of the connector.
            Type = ConnectorSegmentType.Straight,
        };
        connectors.Add(Connector);
    }
}

You can download a complete working sample from GitHub

Displaying Connection between Nodes in Blazor Diagram

  • When you remove NodeConstraints.InConnect from Default, the node accepts only an outgoing connection to dock in it. Similarly, when you remove NodeConstraints.OutConnect from Default, the node accepts only an incoming connection to dock in it.

  • When you remove both InConnect and OutConnect NodeConstraints from Default, the node restricts connector to establish connection in it.

Connections with ports

The SourcePortID and TargetPortID properties allow to create connections between some specific points of source/target nodes.

The following code example illustrates how to create port to port connections.

@using Syncfusion.Blazor.Diagram

<SfDiagramComponent @ref="Diagram" Width="1000px" Height="500px" Nodes="@nodes" Connectors="@connectors">
</SfDiagramComponent>

@code
{
    SfDiagramComponent Diagram;
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();
    DiagramObjectCollection<Node> nodes = new DiagramObjectCollection<Node>();

    protected override void OnInitialized()
    {
        nodes = new DiagramObjectCollection<Node>() 
        {
            new Node()
            {
                OffsetX = 100,
                OffsetY = 100,
                Height = 50,
                Ports = new DiagramObjectCollection<PointPort>()
                {
                    new PointPort()
                    {
                        ID="port1",
                        Visibility = PortVisibility.Visible,
                        Offset = new DiagramPoint() { X = 1, Y = 0.5},
                        Height = 10, Width = 10,
                        Style =  new ShapeStyle(){Fill = "yellow", StrokeColor = "yellow"}
                    }
                },
                Width = 100,
                ID = "node1",
                Style = new ShapeStyle(){ Fill = "#6495ED", StrokeColor = "#6495ED"},
                Shape = new BasicShape() { Type = NodeShapes.Basic, Shape = NodeBasicShapes.Rectangle }
            },
            new Node()
            {
                OffsetX = 300,
                OffsetY = 300,
                Height = 50,
                Width = 100,
                ID = "node2",
                Ports = new DiagramObjectCollection<PointPort>()
                {
                    new PointPort()
                    {
                        ID="port2",
                        Visibility = PortVisibility.Visible,
                        Offset = new DiagramPoint() { X = 0, Y = 0.5},
                        Height = 10, Width = 10,
                        Style =  new ShapeStyle(){Fill = "yellow", StrokeColor = "yellow"}
                    }
                },
                Style = new ShapeStyle(){ Fill = "#6495ED", StrokeColor = "#6495ED" },
                Shape = new BasicShape() { Type = NodeShapes.Basic, Shape = NodeBasicShapes.Rectangle }
              }
        };
        Connector Connector = new Connector()
        {
            ID = "connector1",
            //Source node id of the connector.
            SourceID = "node1",
            //source node port id.
            SourcePortID = "port1",
            //Target node id of the connector.
            TargetID = "node2",
            //Target node port id.
            TargetPortID = "port2",
            TargetDecorator = new DecoratorSettings()
            {
                Style = new ShapeStyle()
                {
                    Fill = "#6495ED",
                    StrokeColor = "#6495ED",
                }
            },
            Style = new ShapeStyle()
            {
                Fill = "#6495ED",
                StrokeColor = "#6495ED",
            },
            // Type of the connector.
            Type = ConnectorSegmentType.Straight,
        };
        connectors.Add(Connector);
    }
}

You can download a complete working sample from GitHub

Connection between Ports in Blazor Diagram

  • When you set PortConstraints to InConnect, the port accepts only an incoming connection to dock in it. Similarly, when you set PortConstraints to OutConnect, the port accepts only an outgoing connection to dock in it.
  • When you set PortConstraints to None, the port restricts connector to establish connection in it.

See also