Search results

Getting started with Blazor Diagram component

This section briefly explains about how to include a Diagram in your Blazor Server-Side application. You can refer Getting Started with Syncfusion Blazor for Server-Side in Visual Studio 2019 page page for the introduction and configuring the common specifications.

Importing Syncfusion Blazor component in the application

  1. Install Syncfusion.Blazor NuGet package to the application by using the NuGet Package Manager. Note: Please ensure to check the Include prerelease option.
  2. You can add the client-side style resources through CDN or from Nuget package in the HEAD element of the ~/Pages/_Host.cshtml page.
<head>
    <environment include="Development">
        <link href="_content/Syncfusion.Blazor/styles/bootstrap4.css" rel="stylesheet" />
        <!---CDN--->
        <!-- <link href="https://cdn.syncfusion.com/blazor/18.1.55/bootstrap4.css" rel="stylesheet" /> -->
     </environment>
</head>

For Internet Explorer 11 kindly refer the polyfills. Refer the documentation for more information.

<head>
    <environment include="Development">
        <link href="_content/Syncfusion.Blazor/styles/bootstrap4.css" rel="stylesheet" />
        <script src="https://github.com/Daddoon/Blazor.Polyfill/releases/download/3.0.1/blazor.polyfill.min.js"></script>
    </environment>
</head>

Adding component package to the application

Open ~/_Imports.Blazor file and import the Syncfusion.Blazor.Diagrams packages.

@using Syncfusion.Blazor
@using Syncfusion.Blazor.Diagrams

Add SyncfusionBlazor service in Startup.cs

Open the Startup.cs file and add services required by Syncfusion components using services.AddSyncfusionBlazor() method. Add this method in the ConfigureServices function as follows.

@using Syncfusion.Blazor;

namespace BlazorApplication
{
    public class Startup
    {
        ....
        ....
        public void ConfigureServices(IServiceCollection services)
        {
            ....
            ....
            services.AddSyncfusionBlazor();
        }
    }
}

Note: To enable custom client side resource loading from CRG or CDN. You need to disable resource loading by AddSyncfusionBlazor(true) and load the scripts in the HEAD element of the ~/Pages/_Host.cshtml page.

<head>
    <environment include="Development">
       <script src="https://cdn.syncfusion.com/blazor/18.1.55/syncfusion-blazor.min.js"></script>
   </environment>
</head>

Adding Diagram component to the Application

Diagram component can be rendered by using the SfDiagram tag helper in ASP.NET Core Blazor application. Add the Diagram component in any web page razor in the Pages folder. For example, the Diagram component is added in the ~/Pages/Index.razor page.

The following example shows a basic Diagram component.

<SfDiagram Width="100%" Height="600px">
</SfDiagram>

Adding Nodes and Connectors

Let us create and add a nodes with specific position, size, label and shape. Connect two or more nodes by using a connectors.

@using Syncfusion.Blazor.Diagrams
@using System.Collections.ObjectModel
@using DiagramShapes = Syncfusion.Blazor.Diagrams.Shapes
@using DiagramSegments = Syncfusion.Blazor.Diagrams.Segments
<SfDiagram  Height="600px" Nodes="@NodeCollection" Connectors="@ConnectorCollection" NodeDefaults="@NodeDefaults"
            ConnectorDefaults="@ConnectorDefaults"></SfDiagram>
@code
{
    int connectorCount = 0;
    // Reference to diagram
    SfDiagram diagram;
    // Defines diagram's nodes collection
    public ObservableCollection<DiagramNode> NodeCollection { get; set; }
    // Defines diagram's connector collection
    public ObservableCollection<DiagramConnector> ConnectorCollection { get; set; }
    // Defines default values for DiagramNode object
    public DiagramNode NodeDefaults { get; set; }
    // Defines default values for DiagramConnector object
    public DiagramConnector ConnectorDefaults { get; set; }
    protected override void OnInitialized()
    {
        InitDiagramModel();
    }

    private void InitDiagramModel()
    {
        InitDiagramDefaults();
        NodeCollection = new ObservableCollection<DiagramNode>();
        ConnectorCollection = new ObservableCollection<DiagramConnector>();
        CreateNode("Start", 50, FlowShapes.Terminator, "Start");
        CreateNode("Init", 140, FlowShapes.Process, "var i = 0;'");
        CreateNode("Condition", 230, FlowShapes.Decision, "i < 10?");
        CreateNode("Print", 320, FlowShapes.PreDefinedProcess, "print(\'Hello!!\');");
        CreateNode("Increment", 410, FlowShapes.Process, "i++;");
        CreateNode("End", 500, FlowShapes.Terminator, "End");
        DiagramConnectorSegment segment1 = new DiagramConnectorSegment()
        {
            Type = DiagramSegments.Orthogonal,
            Length = 30,
            Direction = Direction.Right
        };
        DiagramConnectorSegment segment2 = new DiagramConnectorSegment()
        {
            Type = DiagramSegments.Orthogonal,
            Length = 300,
            Direction = Direction.Bottom
        };
        DiagramConnectorSegment segment3 = new DiagramConnectorSegment()
        {
            Type = DiagramSegments.Orthogonal,
            Length = 30,
            Direction = Direction.Left
        };
        DiagramConnectorSegment segment4 = new DiagramConnectorSegment()
        {
            Type = DiagramSegments.Orthogonal,
            Length = 200,
            Direction = Direction.Top
        };
        CreateConnector("Start", "Init");
        CreateConnector("Init", "Condition");
        CreateConnector("Condition", "Print");
        CreateConnector("Condition", "End", "Yes", segment1, segment2);
        CreateConnector("Print", "Increment", "No");
        CreateConnector("Increment", "Condition", null, segment3, segment4);

    }
    private void CreateConnector(string sourceId, string targetId, string label = default(string), DiagramConnectorSegment segment1 = null, DiagramConnectorSegment segment2 = null)
    {
        DiagramConnector diagramConnector = new DiagramConnector()
        {
            Id = string.Format("connector{0}", ++connectorCount),
            SourceID = sourceId,
            TargetID = targetId
        };

        if (label != default(string))
        {
            var annotation = new DiagramConnectorAnnotation()
            {
                Content = label,
                Style = new AnnotationStyle() { Fill = "white" }
            };
            diagramConnector.Annotations = new ObservableCollection<DiagramConnectorAnnotation>() { annotation };
        }

        if (segment1 != null)
        {
            diagramConnector.Segments = new ObservableCollection<DiagramConnectorSegment>() { segment1, segment2 };
        }

        ConnectorCollection.Add(diagramConnector);
    }

    private void InitDiagramDefaults()
    {
        DiagramNodeAnnotation defaultAnnotation = new DiagramNodeAnnotation()
        {
            Style = new AnnotationStyle()
            {
                Color = "white",
                Fill = "transparent"
            }
        };
        NodeDefaults = new DiagramNode()
        {
            Width = 140,
            Height = 50,
            OffsetX = 300,
            Annotations = new ObservableCollection<DiagramNodeAnnotation>() { defaultAnnotation },
            Style = new NodeShapeStyle() { Fill = "#357BD2", StrokeColor = "white" }
        };

        ConnectorDefaults = new DiagramConnector()
        {
            Type = DiagramSegments.Orthogonal,
            TargetDecorator = new ConnectorTargetDecorator() { Shape = DecoratorShapes.Arrow, Width = 10, Height = 10 }
        };
    }
    private void CreateNode(string id, double y, FlowShapes shape, string label, bool positionLabel = false)
    {
        DiagramNodeAnnotation annotation = new DiagramNodeAnnotation() { Content = label };
        if (positionLabel)
        {
            annotation.Margin = new NodeAnnotationMargin() { Left = 25, Right = 25 };
        };

        DiagramNode diagramNode = new DiagramNode()
        {
            Id = id,
            OffsetY = y,
            Shape = new DiagramShape() { Type = DiagramShapes.Flow, FlowShape = shape },
            Annotations = new ObservableCollection<DiagramNodeAnnotation>() { annotation }
        };
        NodeCollection.Add(diagramNode);
    }
}

Diagram

See Also