GoJS: How can I change Node fill color?

Question

I'm using GoJS to make the diagram.

My diagram configuration (the example from the official documentation):

function init() {
    //......
    // define the Node template
    myDiagram.nodeTemplate =
        $(go.Node, "Auto",
            new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
            // define the node's outer shape, which will surround the TextBlock
            $(go.Shape, "RoundedRectangle",
                {
                    parameter1: 20,  // the corner has a large radius
                    fill: $(go.Brush, "Linear", { 0: "rgb(254, 201, 0)", 1: "rgb(254, 162, 0)" }),
                    stroke: null,
                    portId: "",  // this Shape is the Node's port, not the whole Node
                    fromLinkable: true, fromLinkableSelfNode: true, fromLinkableDuplicates: true,
                    toLinkable: true, toLinkableSelfNode: true, toLinkableDuplicates: true,
                    cursor: "pointer"
                }),
            $(go.TextBlock,
                {
                    font: "bold 11pt helvetica, bold arial, sans-serif",
                    editable: true  // editing the text automatically updates the model data
                },
                new go.Binding("text").makeTwoWay())
        );
//......
}

I'm creating the nodes in the following way:

var nodeOperations = new Object();

    for (var i = 0; i < countState; i++) {           
            var json = {'id': i, 'loc': nodesCenters[i].x +' '+nodesCenters[i].y, 'text': markedStateTable['digitStates'][i] + ', ' + markedStateTable['namedStates'][i]};

            nodes.push(json);
    }

And now I need programmatically change the fill color for specific node. I'm trying this code:

var data = myDiagram.model.findNodeDataForKey(0);

    myDiagram.model.setDataProperty(data, "fill", "green");

But after that, my chart doesn't display. And there are no error in console. Should I set the new shape for the node? Or how can I do that? Thank you for your help!

Answer 1

Please specify the fill color in the nodeArray

var nodeDataArray = [
    { key: 1, text: "Name", fill: "#ff5722", stroke: "#4d90fe", description: "geethu" }];

Then add binding to the textBlock as

 $(go.Shape, "RoundedRectangle", {
                    fill: "#cce6ff" // the default fill, if there is no data-binding
        }, new go.Binding("fill", "fill"))

 myDiagram.nodeTemplate =

    $(go.Node, "Horizontal", {
            isTreeExpanded: false,
            click: showDetail
        },
        $(go.Panel, "Auto",
            $(go.Shape, "RoundedRectangle", {
                fill: "#cce6ff", // the default fill, if there is no data-binding
                stroke: "#6699ff",
                height: 40,
                strokeWidth: 2,
                portId: "",
                cursor: "pointer", // the Shape is the port, not the whole Node
            }, new go.Binding("fill", "fill")),
            $(go.TextBlock, {
                    editable: true
                },
                new go.Binding("text", "text"))
        ),
        $("TreeExpanderButton", { alignment: go.Spot.Bottom, alignmentFocus: go.Spot.Top }, { visible: true })
    );

Answer 2

You need to add a data binding for fill or the value in the node data is meaningless. After all, what would it mean to have data.fill if you had multiple shapes with multiple different fills?

So add new go.Binding("fill") to the relevant shape you want to change:

function init() {
    //......
    // define the Node template
    myDiagram.nodeTemplate =
        $(go.Node, "Auto",
            new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
            // define the node's outer shape, which will surround the TextBlock
            $(go.Shape, "RoundedRectangle",
                {
                    parameter1: 20,  // the corner has a large radius
                    fill: $(go.Brush, "Linear", { 0: "rgb(254, 201, 0)", 1: "rgb(254, 162, 0)" }),
                    stroke: null,
                    portId: "",  // this Shape is the Node's port, not the whole Node
                    fromLinkable: true, fromLinkableSelfNode: true, fromLinkableDuplicates: true,
                    toLinkable: true, toLinkableSelfNode: true, toLinkableDuplicates: true,
                    cursor: "pointer"
                },
            new go.Binding("fill") // NEW
            ),
            $(go.TextBlock,
                {
                    font: "bold 11pt helvetica, bold arial, sans-serif",
                    editable: true  // editing the text automatically updates the model data
                },
                new go.Binding("text").makeTwoWay())
        );
//......
}

But after that, my chart doesn't display.

I don't know why that would be happening. Use go-debug.js to see more warnings.

See also this tutorial on GraphObject manipulation, including using setDataProperty: http://gojs.net/latest/learn/graphobject.html

Answer 3

You can use switch statement based on the node you want to fill based on the property value. Assuming you have a property named 'namedStates' based on which you node color should change, here is my example:

 $(go.Shape, "Rectangle", {
    name: "SHAPE",
    fill: "red",
    stroke: null,
    fromLinkable: true,
    toLinkable: true,
    cursor: "pointer"
}, new go.Binding("fill", "namedStates", function(type) {
    switch (type) {
        case 1:
            return "#FF4081";
        case 2:
            return "#303F9F";
        case 3:
            return "#00796B";
        case 4:
            return "#FF5722";
        case 5:
            return "#5D4037";
        case 6:
            return "#7B1FA2";
        default:
            return '#8BC34A';

    }
})),