htmlwidget draws a new plot when I update a shiny input? - r

Question

I'm creating my first package using htmlwidgetsand I'm having some troubles integrating the output with shiny. When I update an input my widget draws a new plot below the original one instead of just updating the original plot. For example:
This my js code, my guess is that the problem is there:
HTMLWidgets.widget({
name: 'IMPosterior',
type: 'output',
factory: function(el, width, height) {
// TODO: define shared variables for this instance
return {
renderValue: function(opts) {
//transition
var transDuration = 2500;
var dataDiscrete = opts.bars.map((b, i) => {
b.y = Number(b.y);
b.desc = opts.text[i];
return b;
});
var distParams = {
min: d3.min(opts.data, d => d.x),
max: d3.max(opts.data, d => d.x)
};
distParams.cuts = [-opts.MME, opts.MME, distParams.max];
opts.data = opts.data.sort((a,b) => a.x - b.x);
var dataContinuousGroups = [];
distParams.cuts.forEach((c, i) => {
let data = opts.data.filter(d => {
if (i === 0) {
return d.x < c;
} else if (i === distParams.cuts.length - 1) {
return d.x > distParams.cuts[i - 1];
} else {
return d.x < c && d.x > distParams.cuts[i - 1];
}
});
data.unshift({x:data[0].x, y:0});
data.push({x:data[data.length - 1].x, y:0});
dataContinuousGroups.push({
color: opts.colors[i],
data: data
});
});
var margin = {
top: 50,
right: 20,
bottom: 80,
left: 70
},
dims = {
width: width - margin.left - margin.right,
height: height - margin.top - margin.bottom
};
var xContinuous = d3.scaleLinear()
.domain([distParams.min - 1, distParams.max + 1])
.range([0, dims.width]);
var xDiscrete = d3.scaleBand()
.domain(dataDiscrete.map(function(d) { return d.x; }))
.rangeRound([0, dims.width]).padding(0.1);
var y = d3.scaleLinear()
.domain([0, 1])
.range([dims.height, 0]);
var svg = d3.select(el).append("svg")
.attr("width", dims.width + margin.left + margin.right)
.attr("height", dims.height + margin.top + margin.bottom);
var g = svg
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var xAxis = d3.axisBottom()
.scale(xDiscrete);
var yAxis = d3.axisLeft()
.scale(y)
.ticks(10)
.tickFormat(d3.format(".0%"));
var yLabel = g.append("text")
.attr("class", "y-axis-label")
.attr("transform", "rotate(-90)")
.attr("y", -52)
.attr("x", -160)
.attr("dy", ".71em")
.style("text-anchor", "end")
.style("font-size", 14 + "px")
.text("Probability");
g.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + dims.height + ")")
.call(xAxis);
g.append("g")
.attr("class", "y axis")
.call(yAxis);
var areas = g.selectAll(".area")
.data(dataDiscrete)
.enter().append("path")
.attr("class", "area")
.style("fill", function(d) { return d.color; })
.attr("d", function(d, i) {
let numPts = dataContinuousGroups[i].data.length - 2;
var path = d3.path();
path.moveTo(xDiscrete(d.x), y(0));
for (j=0; j<numPts; j++) {
path.lineTo(xDiscrete(d.x) + j*xDiscrete.bandwidth()/(numPts-1), y(d.y));
}
path.lineTo(xDiscrete(d.x) + xDiscrete.bandwidth(), y(0));
return path.toString();
});
var tooltip = d3.tip()
.attr('class', 'd3-tip chart-data-tip')
.offset([30, 0])
.direction('s')
.html(function(d, i) {
return "<span>" + dataDiscrete[i].desc + "</span>";
});
g.call(tooltip);
areas
.on('mouseover', tooltip.show)
.on('mouseout', tooltip.hide);
var thresholdLine = g.append("line")
.attr("stroke", "black")
.style("stroke-width", "1.5px")
.style("stroke-dasharray", "5,5")
.style("opacity", 1)
.attr("x1", 0)
.attr("y1", y(opts.threshold))
.attr("x2", dims.width)
.attr("y2", y(opts.threshold));
var updateXAxis = function(type, duration) {
if (type === "continuous") {
xAxis.scale(xContinuous);
} else {
xAxis.scale(xDiscrete);
}
d3.select(".x").transition().duration(duration).call(xAxis);
};
var updateYAxis = function(data, duration) {
var extent = d3.extent(data, function(d) {
return d.y;
});
extent[0] = 0;
extent[1] = extent[1] + 0.2*(extent[1] - extent[0]);
y.domain(extent);
d3.select(".y").transition().duration(duration).call(yAxis);
};
var toggle = function(to, duration) {
if (to === "distribution") {
updateYAxis(dataContinuousGroups[0].data.concat(dataContinuousGroups[1].data).concat(dataContinuousGroups[2].data), 0);
updateXAxis("continuous", duration);
areas
.data(dataContinuousGroups)
.transition()
.duration(duration)
.attr("d", function(d) {
var gen = d3.line()
.x(function(p) {
return xContinuous(p.x);
})
.y(function(p) {
return y(p.y);
});
return gen(d.data);
});
thresholdLine
.style("opacity", 0);
g.select(".y.axis")
.style("opacity", 0);
g.select(".y-axis-label")
.style("opacity", 0);
} else {
y.domain([0, 1]);
d3.select(".y").transition().duration(duration).call(yAxis);
updateXAxis("discrete", duration);
areas
.data(dataDiscrete)
.transition()
.duration(duration)
.attr("d", function(d, i) {
let numPts = dataContinuousGroups[i].data.length - 2;
var path = d3.path();
path.moveTo(xDiscrete(d.x), y(0));
for (j=0; j<numPts; j++) {
path.lineTo(xDiscrete(d.x) + j*xDiscrete.bandwidth()/(numPts-1), y(d.y));
}
path.lineTo(xDiscrete(d.x) + xDiscrete.bandwidth(), y(0));
return path.toString();
});
thresholdLine
.transition()
.duration(0)
.delay(duration)
.style("opacity", 1)
.attr("y1", y(opts.threshold))
.attr("y2", y(opts.threshold));
g.select(".y.axis")
.transition()
.duration(0)
.delay(duration)
.style("opacity", 1);
g.select(".y-axis-label")
.transition()
.duration(0)
.delay(duration)
.style("opacity", 1);
}
};
// Add buttons
//container for all buttons
var allButtons = svg.append("g")
.attr("id", "allButtons");
//fontawesome button labels
var labels = ["B", "D"];
//colors for different button states
var defaultColor = "#E0E0E0";
var hoverColor = "#808080";
var pressedColor = "#000000";
//groups for each button (which will hold a rect and text)
var buttonGroups = allButtons.selectAll("g.button")
.data(labels)
.enter()
.append("g")
.attr("class", "button")
.style("cursor", "pointer")
.on("click", function(d, i) {
updateButtonColors(d3.select(this), d3.select(this.parentNode));
d3.select("#numberToggle").text(i + 1);
if (d === "D") {
toggle("distribution", transDuration);
} else {
toggle("discrete", transDuration);
}
})
.on("mouseover", function() {
if (d3.select(this).select("rect").attr("fill") != pressedColor) {
d3.select(this)
.select("rect")
.attr("fill", hoverColor);
}
})
.on("mouseout", function() {
if (d3.select(this).select("rect").attr("fill") != pressedColor) {
d3.select(this)
.select("rect")
.attr("fill", defaultColor);
}
});
var bWidth = 40; //button width
var bHeight = 25; //button height
var bSpace = 10; //space between buttons
var x0 = 20; //x offset
var y0 = 10; //y offset
//adding a rect to each toggle button group
//rx and ry give the rect rounded corner
buttonGroups.append("rect")
.attr("class", "buttonRect")
.attr("width", bWidth)
.attr("height", bHeight)
.attr("x", function(d, i) {
return x0 + (bWidth + bSpace) * i;
})
.attr("y", y0)
.attr("rx", 5) //rx and ry give the buttons rounded corners
.attr("ry", 5)
.attr("fill", defaultColor);
//adding text to each toggle button group, centered
//within the toggle button rect
buttonGroups.append("text")
.attr("class", "buttonText")
.attr("x", function(d, i) {
return x0 + (bWidth + bSpace) * i + bWidth / 2;
})
.attr("y", y0 + bHeight / 2)
.attr("text-anchor", "middle")
.attr("dominant-baseline", "central")
.attr("fill", "white")
.text(function(d) {
return d;
});
function updateButtonColors(button, parent) {
parent.selectAll("rect")
.attr("fill", defaultColor);
button.select("rect")
.attr("fill", pressedColor);
}
toggle("distribution", 0);
setTimeout(() => {
toggle("discrete", transDuration);
}, 1000);
},
resize: function(width, height) {
// TODO: code to re-render the widget with a new size
}
};
}
});
This is the code for the shiny app:
# Gen data --------------------------------------------------------------
set.seed(9782)
x <- rnorm(1000)
# Usy my widget -----------------------------------------------------------
library(IMPosterior)
IMPosterior(x= x, MME=1)
## app.R ##
library(shiny)
library(shinydashboard)
library(IMPosterior) # https://github.com/ignacio82/IMPosterior
ui <- dashboardPage(
dashboardHeader(),
dashboardSidebar(
sliderInput(
"threshold",
h4("Threshold:"),
min = 50,
max = 99,
value = 75,
step = 1,
post = "%"
)
),
dashboardBody(
box(
title = "Posterior Distribution",
status = "primary",
solidHeader = TRUE,
width = 6,
IMPosteriorOutput("plot", height = "350px")
)
)
)
server <- function(input, output) {
output$plot <- renderIMPosterior({
p <- IMPosterior(x = x, MME = 1, threshold = input$threshold/100)
return(p)
})
}
shinyApp(ui, server)
What am I doing wrong?

Answer 1

I'm not sure if this is the best way to solve the problem, but it does. I just needed to add .html("") to my svg right after I select el
var svg = d3.select(el).html("").append("svg")
.attr("width", dims.width + margin.left + margin.right)
.attr("height", dims.height + margin.top + margin.bottom);