Connector in AngularJS Diagram

18 Jan 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 start and end points. The path to be drawn can be defined with a collection of segments.
To explore the properties of a connector, refer to Connector Properties.

Add connectors through connectors collection

The sourcePoint and targetPoint properties of connector allow you to define the end points of a connector. The following code example illustrates how to add a connector through connector collection.

JAVASCRIPT

<div ng-controller="diagramCtrl">
    <ej-diagram id="diagramCore" e-height="500px" e-width="700px" e-connectors="connectors">
    </ej-diagram>
</div>

JAVASCRIPT

//Creates connector
var connectors = [
    // Defines JSON
    {
        //Name of the connector
        name: "connector",
        //Sets source and target points
        sourcePoint: {
            x: 100,
            y: 100
        },
        targetPoint: {
            x: 200,
            y: 200
        }
    }
];

//Initializes Diagram
syncApp.controller('diagramCtrl', function($scope) {
    //Assigns connectors collection to the Diagram
    $scope.connectors = connectors;
});

Add connector at run time

Connectors can be added at runtime with the client side method, add. The following code example illustrates how to add connector at runtime.

JAVASCRIPT

// Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    }
};
var diagram = $("#DiagramContent").ejDiagram("instance");
// Adds to the Diagram
diagram.add(connector);

Connectors from palette

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

For more information about adding connectors from symbol palette, refer to Symbol Palette.

Connectors through data source

Connectors are automatically generated based on the relationships defined through the data source.
The default properties for these connectors are fetched from default settings.

For more information about data source, refer to Data Binding.

Draw connectors

Connectors can be interactively drawn by clicking and dragging on the Diagram surface by using DrawingTool. For more information about drawing connectors, refer to Draw Connectors.

Update Connector at runtime

The client side method, updateConnector is used to update the connectors at run time. The following code example illustrates how to update a connector at runtime.

JAVASCRIPT

var diagram = $("#DiagramContent").ejDiagram("instance");
diagram.updateConnector("connectorName", {
    lineColor: "#1BA0E2",
    lineWidth: 5,
    lineDashArray: "5,5"
});

Connect nodes

The SourceNode and targetNode properties allow to define the nodes to be connected. The following code example illustrates how to connect two nodes.

HTML

<div ng-controller="diagramCtrl">
    <ej-diagram id="diagramCore" e-height="500px" e-width="700px" e-nodes="nodes" e-defaultsettings="defaultSettings" e-connectors="connectors">
    </ej-diagram>
</div>

JAVASCRIPT

// Defines JSON to create tasks
var task1 = {
    name: "task1",
    offsetX: 200,
    offsetY: 200,
    labels: [{
        text: "Task 1"
    }]
};
var task2 = {
    name: "task2",
    offsetX: 400,
    offsetY: 200,
    labels: [{
        text: "Task 2"
    }]
};

//Adds tasks to nodes collection
var nodes = [
    task1,
    task2
];

var connectors = [{
    //Name of the connector
    name: "flow1",

    //Name of the source and target nodes
    sourceNode: "task1",
    targetNode: "task2"
}];

//Initializes Diagram
syncApp.controller('diagramCtrl', function($scope) {
    //Sets nodes collection to the Diagram model
    $scope.nodes = nodes;
    //Assigns connectors collection to the Diagram
    $scope.connectors = connectors;
    //Defines the properties that carry the common values
    $scope.defaultSettings = {
        //Defines the common values for the nodes
        node: {
            width: 100,
            height: 50,
            fillColor: "darkCyan",
            borderColor: "black",
            type: ej.datavisualization.Diagram.Shapes.Flow,
            shape: ej.datavisualization.Diagram.FlowShapes.Process,
            labels: [{
                fontColor: "white"
            }]
        }
    }
});

NOTE

By default, connections are created at the intersecting point of segments and node bounds. The connection between any specific point of source and target nodes can be achieved with connection ports.

Connections with ports

The sourcePort and targetPort 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.

HTML

<div ng-controller="diagramCtrl">
    <ej-diagram id="diagramCore" e-height="500px" e-width="700px" e-nodes="nodes" e-defaultsettings="defaultSettings" e-connectors="connectors">
    </ej-diagram>
</div>

JAVASCRIPT

//Defines ports for task2
var ports = [{
        name: "in",
        offset: {
            x: 1,
            y: 0.65
        },
        shape: "circle",
        visibility: "visible",
        fillColor: "black"
    },
    {
        name: "out",
        offset: {
            x: 1,
            y: 0.35
        },
        shape: "circle",
        visibility: "visible",
        fillColor: "black"
    }
];

// Defines JSON to create tasks
var task1 = {
    name: "task1",
    offsetX: 350,
    offsetY: 300,
    labels: [{
        text: "Task 1"
    }]
};
var task2 = {
    name: "task2",
    offsetX: 200,
    offsetY: 250,
    labels: [{
        text: "Task 2"
    }],
    // Adds ports to node
    ports: ports
};
var task3 = {
    name: "task3",
    offsetX: 350,
    offsetY: 200,
    labels: [{
        text: "Task 3"
    }]
};

//Adds tasks to nodes collection
var nodes = [task1, task2, task3];
var connectors = [{
    name: "flow1",
    sourceNode: "task1",
    targetNode: "task2",
    //Name of the target port defined in the target node
    targetPort: "in"
}, {
    name: "flow2",
    sourceNode: "task2",
    targetNode: "task3",
    //Name of the source port defined in the source node
    sourcePort: "out"
}];

//Initializes Diagram
syncApp.controller('diagramCtrl', function($scope) {
    //Sets nodes collection to the Diagram model
    $scope.nodes = nodes;
    //Assigns connectors collection to the Diagram
    $scope.connectors = connectors;
    //Defines the properties that carry the common values
    $scope.defaultSettings = {
        //Defines the common values for the nodes
        node: {
            width: 100,
            height: 50,
            fillColor: "darkCyan",
            borderColor: "black",
            type: ej.datavisualization.Diagram.Shapes.Flow,
            shape: ej.datavisualization.Diagram.FlowShapes.Process,
            labels: [{
                fontColor: "white"
            }]
        }
        //Defines common values for connectors
        connector: {
            segments: [{
                type: "orthogonal"
            }]
        }
    }
});

Segments

The path of the connector is defined with a collection of segments. There are three types of segments.

Straight

Straight segment allows to create a straight line.
To create a straight line, you should specify the type of the segment as “straight” and add a straight segment to segments collection. The following code example illustrates how to create a default straight segment.

JAVASCRIPT

var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    },

    //Defines segment collection
    segments: [{
        //When there is no previous segment, line starts from source point
        //When the end point is not specified, line ends at target point
        //Defines the type of the segment
        type: "straight"
    }]
};
connectors.push(connector);

The point property of straight segment allows you to define the end point of it. The following code example illustrates how to define the end point of a straight segment.

JAVASCRIPT

var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 300
    },
    //Defines segment collection
    segments: [{
        // Defines the type of the segment
        type: "straight",
        // Defines the end point of the segment
        point: {
            x: 100,
            y: 200
        }
        // Additional straight line will be drawn from this end point to the target point
    }]
};
connectors.push(connector);

Orthogonal

Orthogonal segments are used to create segments that are perpendicular to each other.

Set the segment type as “orthogonal” to create a default orthogonal segment. The following code example illustrates how to create a default orthogonal segment.

JAVASCRIPT

var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    },
    //Defines segment collection
    segments: [{
        // Define the type of the segment
        type: "orthogonal"
    }]
};
connectors.push(connector);

The length and direction properties allow to define the flow and length of segment. The following code example illustrates how to create customized orthogonal segments.

JAVASCRIPT

var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    },
    //Defines segment collection
    segments: [{
        // Orthogonal segment of 50px length to the bottom
        type: "orthogonal",
        length: 50,
        direction: "bottom"
        // Additional orthogonal segments will be added from the end of the last segment to the target point
    }]
};
connectors.push(connector);

Avoid overlapping

Orthogonal segments are automatically re-routed, in order to avoid overlapping with the source and target nodes. The following images illustrate how orthogonal segments are re-routed.

NOTE

Overlapping with source and target nodes are only avoided. Other nodes are not considered as obstacles.

Bezier

Bezier segments are used to create curve segments and the curves are configurable either with the control points or with vectors.

To create a bezier segment, the segment.type is set as bezier. The following code example illustrates how to create a default Bezier segment.

JAVASCRIPT

var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    },
    //Defines segment collection
    segments: [{
        // Defines the type of the segment
        type: "bezier"
    }]
};
connectors.push(connector);

The point1 and point2 properties of bezier segment enable you to set the control points. The following code example illustrates how to configure the Bezier segments with control points.

JAVASCRIPT

var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 200
    },
    targetPoint: {
        x: 250,
        y: 200
    },
    //Defines segment collection
    segments: [{
        // Defines the type of the segment
        type: "bezier",
        // First control point: an absolute position from the page origin
        point1: {
            x: 125,
            y: 75
        },
        // Second control point: an absolute position from the page origin
        point2: {
            x: 225,
            y: 75
        }
    }]
};
connectors.push(connector);

The vactor1 and vector2 properties of bezier segment enable you to define the vectors. The following code illustrates how to configure a bezier curve with vectors.

JAVASCRIPT

//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 200
    },
    targetPoint: {
        x: 250,
        y: 200
    },
    //Defines segment collection
    segments: [{
        // Defines the type of the segment
        type: "bezier",
        // Length and angle between the source point and the first control point
        vector1: {
            angle: 270,
            distance: 75
        },
        // Length and angle between the target point and the second control point
        vector2: {
            angle: 270,
            distance: 75
        }
    }]
};
connectors.push(connector);

Complex segments

Multiple segments can be defined one after another. To create a connector with multiple segments, define and add the segments to connector.segments collection. The Following code example illustrates how to create a connector with multiple segments.

JAVASCRIPT

var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 200
    },
    targetPoint: {
        x: 250,
        y: 300
    },
    //Defines segment collection
    segments: [{
            // Segment of length 100px to the bottom
            type: "orthogonal",
            length: 150,
            direction: "bottom"
        }, {
            //Defines a segment of 150px length to the right
            type: "orthogonal",
            direction: "right",
            length: 150
        }
        //Additional orthogonal segments will be added from the end of the last segment to the target point
    ]
};
connectors.push(connector);

Decorator

Start and end points of a connector can be decorated with some customizable shapes like arrows, circles, diamond or path. You can decorate the connection end points with the sourceDecorator and targetDecorator properties of connector.
To explore the properties of decorators, refer to Decorator Properties.

The shape property of decorator allows to define the shape of the decorators. The following code example illustrates how to create decorators of various shapes.

JAVASCRIPT

var DecoratorShapes = ej.datavisualization.Diagram.DecoratorShapes;
var connectors = [];
//Defines JSON
var connector = {
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    },
    // Decorator shape- circle
    sourceDecorator: {
        shape: DecoratorShapes.Circle,
        width: 10,
        height: 10
    },
    // Decorator shape - Arrow
    targetDecorator: {
        shape: DecoratorShapes.Arrow,
        width: 10,
        height: 10
    }
};
connectors.push(connector);

var connector2 = {
    name: "connector2",
    sourcePoint: {
        x: 300,
        y: 100
    },
    targetPoint: {
        x: 400,
        y: 200
    },
    // Decorator shape - Open arrow
    sourceDecorator: {
        shape: DecoratorShapes.Diamond,
        width: 10,
        height: 10
    },
    // Decorator shape - Diamond
    targetDecorator: {
        shape: DecoratorShapes.OpenArrow,
        width: 10,
        height: 10
    }
};
connectors.push(connector2);

var connector3 = {
    name: "connector3",
    sourcePoint: {
        x: 500,
        y: 100
    },
    targetPoint: {
        x: 600,
        y: 200
    },

    // Decorator shape - Path
    targetDecorator: {
        shape: DecoratorShapes.Path,
        pathData: "M 376.892,225.284L 371.279,211.95L 376.892,198.617L 350.225,211.95L 376.892,225.284 Z"
    }
};
connectors.push(connector3);

Padding

Padding is used to leave space between the Connector’s end point and the object to where it is connected.

The sourcePadding and targetPadding properties of connector define the space to be left between the connection end points and the source and target nodes of connector. The following code example illustrates how to leave space between the connection end points and source, target nodes.

JAVASCRIPT

// Defines JSON to create tasks
var task1 = {
    name: "task1",
    offsetX: 200,
    offsetY: 200,
    labels: [{
        text: "Task 1"
    }]
};
var task2 = {
    name: "task2",
    offsetX: 400,
    offsetY: 200,
    labels: [{
        text: "Task 2"
    }]
};

//Adds tasks to nodes collection
var nodes = [
    task1,
    task2
];

var connectors = [{
    name: "flow1",
    sourceNode: "task1",
    targetNode: "task2",
    // Space between source point and source object
    sourcePadding: 5,
    // Space between target point and target object
    targetPadding: 10
}];

The connectorPadding property of node defines the space to be left between the node bounds and its edges. The following code example illustrates how to leave the space between a node and its connections.

JAVASCRIPT

// Defines JSON to create tasks
var task1 = {
    name: "task1",
    offsetX: 200,
    offsetY: 200,
    labels: [{
        text: "Task 1"
    }],
    //Space between the node and its edges
    connectorPadding: 5
};

var task2 = {
    name: "task2",
    offsetX: 400,
    offsetY: 200,
    labels: [{
        text: "Task 2"
    }]
};

//Adds tasks to nodes collection
var nodes = [
    task1,
    task2
];
var connectors = [
    //Defines JSON
    {
        name: "flow1",
        sourceNode: "task1",
        targetNode: "task2"
    }
];

The connectorPadding property of port defines the space between the ports and its in/out edges. The following code example illustrates how to leave the space between ports and its connections.

JAVASCRIPT

// Defines JSON to create tasks
var ports = [{
    name: "port",
    offset: {
        x: 0,
        y: 0.5
    },
    shape: "circle",
    visibility: "visible",
    fillColor: "black",
    //Space between port and its edges
    connectorPadding: 5
}];

var task1 = {
    name: "task1",
    offsetX: 200,
    offsetY: 200,
    labels: [{
        text: "Task 1"
    }]
};
var task2 = {
    name: "task2",
    offsetX: 400,
    offsetY: 200,
    labels: [{
        text: "Task 2"
    }],
    ports: ports
};

//Adds tasks to nodes collection

var nodes = [
    task1,
    task2
];

var connectors = [
    //Defines JSON
    {
        name: "flow1",
        sourceNode: "task1",
        targetNode: "task2",
        targetPort: "port"
    }
];

Bridging

Line Bridging creates a bridge for lines to smartly cross over other lines, at points of intersection. When two line connectors meet each other, the line with the higher z-order (upper one) draws an arc over the underlying connector.
Bridging can be enabled/disabled either with the connector.constraints or diagram.constraints. The following code example illustrates how to enable line bridging.

HTML

<div ng-controller="diagramCtrl">
    <ej-diagram id="diagram" e-height="500px" e-width="100%" e-connectors="connectors" e-constraints="constraints">
    </ej-diagram>
</div>

JAVASCRIPT

var Diagram = ej.datavisualization.Diagram;
//Enables briding for a single connector
var connector = {
    name: "connector1",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    },
    constraints: Diagram.ConnectorConstraints.Default
        // Removes inherit bridging or else bridging is enabled/disabled based on the Diagram constraints
        &
        ~Diagram.ConnectorConstraints.InheritBridging
        //Includes bridging
        |
        Diagram.ConnectorConstraints.Bridging
};
//Enables bridging for every connector added in the model
syncApp.controller('diagramCtrl', function($scope) {
    $scope.connectors = connectors;
    $scope.constraints: Diagram.DiagramConstraints.Default |
        Diagram.DiagramConstraints.Bridging
});

The direction of the bridge can be customized with the property bridgeDirection. BridgeDirection defines the intersecting segment where the bridge has to be inserted. By default, the bridge direction points to the top.

To explore the bridge directions, refer to Bridge Directions.

The following code example illustrates how to draw the bridge at the bottom direction.

JAVASCRIPT

var DiagramConstraints = ej.datavisualization.Diagram.DiagramConstraints;

//Enables bridging for every connector added in the model
syncApp.controller('diagramCtrl', function($scope) {
    $scope.connectors = connectors;
    //Sets the bridge direction
    bridgeDirection: "bottom",
        //Enables bridging
        constraints: DiagramConstraints.Default | DiagramConstraints.Bridging
});

Limitation: Bezier segments do not support bridging.

Corner radius

Corner radius allows to create connectors with rounded corners. The radius of the rounded corner is set with cornerRadius property.

JAVASCRIPT

// Defines JSON to create tasks
var task1 = {
    name: "task1",
    offsetX: 200,
    offsetY: 200,
    labels: [{
        text: "Task 1"
    }]
};
var task2 = {
    name: "task2",
    offsetX: 350,
    offsetY: 300,
    labels: [{
        text: "Task 2"
    }]
};

//Adds tasks to nodes collection
var nodes = [
    task1,
    task2
];

var connectors = [
    //Defines JSON
    {
        name: "flow1",
        sourceNode: "task1",
        targetNode: "task2",
        //Sets the radius for the rounded corner
        cornerRadius: 10
    }
];

Appearance

Stroke width, stroke color, and style of the lines and decorators can be customized with a set of defined properties.

Segment Appearance

The following code example illustrates how to customize the segment appearance.

JAVASCRIPT

//Customizes the appearance of the connector
var connectors = [{
    name: "connector",
    sourcePoint: {
        x: 100,
        y: 100
    },
    targetPoint: {
        x: 200,
        y: 200
    },
    //Stroke width of the line
    lineWidth: 2,
    //Stroke color
    lineColor: "green",
    //Line style
    lineDashArray: "2,2",
    //Opacity of the line
    opacity: 0.8,
    //Defined in the decorator appearance section
    targetDecorator: targetDecorator
}];

Decorator Appearance

The following code example illustrates how to customize the appearance of the decorator.

JAVASCRIPT

//Customizes the appearance of decorator
var targetDecorator = {
    //Defines the shape
    shape: ej.datavisualization.Diagram.DecoratorShapes.Arrow,
    //Fills color of the decorator
    fillColor: "red",
    //Stroke color
    borderColor: "green",
    //Stroke width
    borderWidth: 2,
    width: 10,
    height: 10
};

Interaction

Diagram allows to edit the connectors at runtime. To edit the connector segments at runtime, refer to Connection Editing.

Constraints

The constraints property of connector allows to enable/disable certain features of connectors. For more information about constraints, refer to Connector Constraints.