Custom Visual for Power BI: Thermometer

Thermometer.ts

module powerbi.visuals {
    export interface ViewModel {
        value: number;
        color?: string;
        min?: number;
        max?: number;
    }

    export class Thermometer implements IVisual {
        public static capabilities: VisualCapabilities = {
            dataRoles: [
                {
                    name: 'Category',
                    kind: powerbi.VisualDataRoleKind.Grouping,
                    displayName: 'Time'
                },
                {
                    name: 'Y',
                    kind: powerbi.VisualDataRoleKind.Measure,
                    displayName: 'Temperature'
                },
            ],
            dataViewMappings: [{
                categorical: {
                    categories: {
                        for: { in: 'Category' },
                        dataReductionAlgorithm: { bottom: {} }
                    },
                    values: {
                        select: [{ for: { in: 'Y' } }],
                        dataReductionAlgorithm: { bottom: {} }
                    },
                }
            }],
            objects: {
                general: {
                    displayName: 'General',
                    properties: {
                        fill: {
                            type: { fill: { solid: { color: true } } },
                            displayName: 'Fill'
                        },
                        max: {
                            type: { numeric: true },
                            displayName: 'Max'
                        },
                        min: {
                            type: { numeric: true },
                            displayName: 'Min'
                        }
                    },
                    
                }
            },
        };

        public static converter(dataView: DataView, colors: IDataColorPalette): ViewModel {
            var series = dataView.categorical.values;
            return { value: series[0].values[series[0].values.length-1]}
        }

        private svg: D3.Selection;
        private backCircle: D3.Selection;
        private backRect: D3.Selection;
        private fillCircle: D3.Selection;
        private fillRect: D3.Selection;
        private tempMarkings: D3.Selection;
        private text: D3.Selection;
        private data: ViewModel;
        private dataView: DataView;
        
        /** This is called once when the visual is initialially created */
        public init(options: VisualInitOptions): void {
            var svg = this.svg = d3.select(options.element.get(0))
                .append('svg')
                .classed('thermometer', true);

            var mainGroup = svg.append('g');
            this.backRect = mainGroup.append('rect');
            this.backCircle = mainGroup.append('circle');
            this.fillRect = mainGroup.append('rect');
            this.fillCircle = mainGroup.append('circle');
            this.text = mainGroup.append('text');
            this.tempMarkings = svg.append("g")
                .attr("class", "y axis");
        }

        /** Update is called for data updates, resizes & formatting changes */
        public update(options: VisualUpdateOptions) {
            if(!options.dataViews) return;
            window.console.log('has data')
            var dataView = this.dataView = options.dataViews[0];
            this.data = Thermometer.converter(options.dataViews[0],null);
            this.data.max = Thermometer.getValue(dataView,'max',90);
            this.data.min = Thermometer.getValue(dataView,'min',28);
            var viewport = options.viewport;
            var height = viewport.height;
            var width = viewport.width;
            var duration = options.suppressAnimations?0: 1000;

            this.svg.attr({ 'height': height, 'width': width });
            this.draw(width, height, duration);
        }

        public draw(width: number, height: number, duration: number) {
            var radius = height * 0.1;
            var padding = radius * 0.25;
                        
            this.drawBack(width, height, radius);
            this.drawFill(width, height, radius, padding, duration);
            this.drawTicks(width,height,radius, padding);
            this.drawText(width, height, radius, padding);
        }
        
        public drawBack(width: number, height: number, radius: number){
            var rectHeight = height - radius;
            var fill = 'D3C8B4';
            this.backCircle
                .attr({
                    'cx': width / 2,
                    'cy': rectHeight,
                    'r': radius
                })
                .style({
                    'fill': fill
                });

            this.backRect
                .attr({
                'x': (width - radius) / 2,
                'y': 0,
                'width': radius,
                'height': rectHeight
            })
                .style({
                'fill': fill
            })
        }

        public drawFill(width: number, height: number, radius: number, padding: number, duration: number) {
            var innerRadius = radius * 0.8;
            var fillWidth = innerRadius * 0.7;
            var ZeroValue = height - (radius * 2) - padding;
            var fill = Thermometer.getFill(this.dataView).solid.color;
            
            var min = this.data.min;
            var max = this.data.max;
            var value = this.data.value > max ? max : this.data.value;
            
            var percentage = (ZeroValue - padding) * ((value - min)/(max-min))

            var rectHeight = height - radius;
            this.fillCircle.attr({
                'cx': width / 2,
                'cy': rectHeight,
                'r': innerRadius
            }).style({
                'fill': fill
            });

            this.fillRect
                            .style({
                'fill': fill
            })
            .attr({
                'x': (width - fillWidth) / 2,
                'width': fillWidth,
            })
                .transition()
                .duration(duration)
                .attr({
                'y': ZeroValue - percentage,
                'height': rectHeight - ZeroValue +percentage
            })
        }
        
        private drawTicks(width: number, height: number, radius: number, padding: number){
           var y = d3.scale.linear().range([height - (radius * 2) - padding, padding]);
           var yAxis = d3.svg.axis().scale(y).ticks(4).orient("right");

            y.domain([this.data.min, this.data.max]).nice();

            this.tempMarkings
                .attr("transform", "translate(" + ((width + radius) / 2 + (radius * 0.15)) + ",0)")
                .style({
                    'font-size':(radius * 0.03) + 'em',
                    'font-family': 'Tahoma',
                    'stroke':'none',
                    'fill': '#333'
                })
                .call(yAxis);
            
             this.tempMarkings.selectAll('.axis line, .axis path')
                .style({'stroke': '#333', 'fill': 'none'});
        }
        
        private drawText(width: number, height: number, radius: number, padding: number){       
            this.text
                .text((this.data.value > this.data.max ? this.data.max : this.data.value)|0)
                .attr({ 'x': width / 2, y: height - radius, 'dy': '.35em' })
                .style({ 
                    'fill': 'white', 
                    'text-anchor': 'middle', 
                    'font-family': 'impact', 
                    'font-size': (radius * 0.055) + 'em' })
        }
        
        public enumerateObjectInstances(options: EnumerateVisualObjectInstancesOptions): VisualObjectInstance[] {
            var instances: VisualObjectInstance[] = [];
            var dataView = this.dataView;
            switch (options.objectName) {
                case 'general':
                    var general: VisualObjectInstance = {
                        objectName: 'general',
                        displayName: 'General',
                        selector: null,
                        properties: {
                            fill: Thermometer.getFill(dataView),
                            max: Thermometer.getValue(dataView,'max',90),
                            min: Thermometer.getValue(dataView,'min',28)
                        }
                    };
                    instances.push(general);
                    break;
            }

            return instances;
        }
        
        private static getFill(dataView: DataView): Fill {
            if (dataView) {
                var objects = dataView.metadata.objects;
                if (objects) {
                    var general = objects['general'];
                    if (general) {
                        var fill = <Fill>general['fill'];
                        if (fill)
                            return fill;
                    }
                }
            }
            return { solid: { color: '#C02942'} };
        }
        
        private static getValue(dataView: DataView, key: string, defaultValue: number): number {
            if (dataView) {
                var objects = dataView.metadata.objects;
                if (objects) {
                    var general = objects['general'];
                    if (general) {
                        var size = <number>general[key];
                        if (size != null)
                            return size;
                    }
                }
            }
            return defaultValue;
        }
    }
}