Adding a Title to a Chart.js line graph - javascript

I'm trying to use fillText to draw on a chart.js canvas after it is rendered and it will not work. The best I can do is change the font of the chart. Here is my code.
var options = {
//Boolean - If we show the scale above the chart data
scaleOverlay: false,
//Boolean - If we want to override with a hard coded scale
scaleOverride: false,
//** Required if scaleOverride is true **
//Number - The number of steps in a hard coded scale
scaleSteps: null,
//Number - The value jump in the hard coded scale
scaleStepWidth: null,
//Number - The scale starting value
scaleStartValue: null,
//String - Colour of the scale line
scaleLineColor: "rgba(0,0,0,.1)",
//Number - Pixel width of the scale line
scaleLineWidth: 1,
//Boolean - Whether to show labels on the scale
scaleShowLabels: true,
//Interpolated JS string - can access value
scaleLabel: "<%=value%>",
//String - Scale label font declaration for the scale label
scaleFontFamily: "'Arial'",
//Number - Scale label font size in pixels
scaleFontSize: 12,
//String - Scale label font weight style
scaleFontStyle: "normal",
//String - Scale label font colour
scaleFontColor: "#666",
///Boolean - Whether grid lines are shown across the chart
scaleShowGridLines: true,
//String - Colour of the grid lines
scaleGridLineColor: "rgba(0,0,0,.05)",
//Number - Width of the grid lines
scaleGridLineWidth: 1,
//Boolean - Whether the line is curved between points
bezierCurve: true,
//Boolean - Whether to show a dot for each point
pointDot: true,
//Number - Radius of each point dot in pixels
pointDotRadius: 3,
//Number - Pixel width of point dot stroke
pointDotStrokeWidth: 1,
//Boolean - Whether to show a stroke for datasets
datasetStroke: true,
//Number - Pixel width of dataset stroke
datasetStrokeWidth: 2,
//Boolean - Whether to fill the dataset with a colour
datasetFill: true,
//Boolean - Whether to animate the chart
animation: false,
//Number - Number of animation steps
animationSteps: 60,
//String - Animation easing effect
animationEasing: "easeOutQuart",
//Function - Fires when the animation is complete
onAnimationComplete: null
}
Chart Data labels and points are arrays.
var chartData = {
labels: labels,
datasets: [
{
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,1)",
pointColor: "rgba(220,220,220,1)",
pointStrokeColor: "#fff",
data: points
}
]
}
var ctx = $("#" + item.logon).get(0).getContext("2d");
var chart = new Chart(ctx).Line(chartData, options);
This is done with JSON data and after the call I have:
$("canvas").each(function (i, item) {
var context = $(this).get(0).getContext("2d");
context.textBaseline = 'top';
context.fillText('Test', 0, 0);
});
The graphs just load normally without any text. If I use the context.font then all of the labels on each canvas is changed. I have turned off loading animation. Any ideas?

Instead of drawing on the canvas, I simply add a label around the element
<label for = "idOfCanvas">
Your Label<br />
<canvas></canvas>
</label>

You'd need to add the title with specifics in your options section and ensure display is set to true. Something like so:
options: {
title: {
display: true,
text: 'Name of Your Line Chart'
}
}
Here's a link to the Chartjs documentation

In the option add this parameter
multiTooltipTemplate: "<%= datasetLabel %> - <%= value %>"

Related

ChartJS - set min. for Y axis

I have a chart that shows Total Sales figures. The Problem is that I do not want to show the line chart from 0 USD but instead from 50 USD?
I saw this answer which solved the problem by overriding the settings onLoad, but I cant get it to work for me. There has to be a clear way of doing this, no?
<canvas id="salesChart" style="height: 180px;"></canvas>
<script>
// Get context with jQuery - using jQuery's .get() method.
var salesChartCanvas = $("#salesChart").get(0).getContext("2d");
// This will get the first returned node in the jQuery collection.
var salesChart = new Chart(salesChartCanvas);
var salesChartData = {
labels: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"],
datasets: [
{
label: "HeartBeat",
fillColor: "rgba(60,141,188,0.9)",
strokeColor: "rgba(60,141,188,0.8)",
pointColor: "#3b8bba",
pointStrokeColor: "rgba(60,141,188,1)",
pointHighlightFill: "#fff",
pointHighlightStroke: "rgba(60,141,188,1)",
data: [89.90, 94.00, 87.64, 90.91, 93.41, 88.89, 94.17, 92.00, 93.68, 96.15, 0.00, 0.00]
}
]
};
var salesChartOptions = {
showScale: true, //Boolean - If we should show the scale at all
scaleShowGridLines: true, //Boolean - Whether grid lines are shown across the chart
scaleGridLineColor: "rgba(0,0,0,.05)", //String - Colour of the grid lines
scaleGridLineWidth: 1, //Number - Width of the grid lines
scaleShowHorizontalLines: true, //Boolean - Whether to show horizontal lines (except X axis)
scaleShowVerticalLines: true, //Boolean - Whether to show vertical lines (except Y axis)
bezierCurve: true, //Boolean - Whether the line is curved between points
bezierCurveTension: 0.3, //Number - Tension of the bezier curve between points
pointDot: true, //Boolean - Whether to show a dot for each point
pointDotRadius: 4, //Number - Radius of each point dot in pixels
pointDotStrokeWidth: 1, //Number - Pixel width of point dot stroke
pointHitDetectionRadius: 20, //Number - amount extra to add to the radius to cater for hit detection outside the drawn point
datasetStroke: true, //Boolean - Whether to show a stroke for datasets
datasetStrokeWidth: 2, //Number - Pixel width of dataset stroke
datasetFill: true, //Boolean - Whether to fill the dataset with a color
//String - A legend template
legendTemplate: "<ul class=\"<%=name.toLowerCase()%>-legend\"><% for (var i=0; i<datasets.length; i++){%><li><span style=\"background-color:<%=datasets[i].lineColor%>\"></span><%=datasets[i].label%></li><%}%></ul>",
//Boolean - whether to maintain the starting aspect ratio or not when responsive, if set to false, will take up entire container
maintainAspectRatio: true,
//Boolean - whether to make the chart responsive to window resizing
responsive: true
};
//Create the line chart
salesChart.Line(salesChartData, salesChartOptions);
</script>

Hide label on xAxis in Line-Chart in canvas Html5

I am implementing line chart and I want to hide x'Axis label from line chart. I putted scaleFontSize: 0, , Than x'Axis and Y'axis labels are hide. But I want to hide only x'Axis label.
var lineOptions = {
///Boolean - Whether grid lines are shown across the chart
scaleShowGridLines : true,
//String - Colour of the grid lines
scaleGridLineColor : "rgba(0,0,0,.05)",
//Number - Width of the grid lines
scaleGridLineWidth : 1,
//Boolean - Whether the line is curved between points
bezierCurve : true,
//Number - Tension of the bezier curve between points
bezierCurveTension : 0.4,
//Boolean - Whether to show a dot for each point
pointDot : true,
//Number - Radius of each point dot in pixels
pointDotRadius : 4,
//Number - Pixel width of point dot stroke
pointDotStrokeWidth : 1,
//Number - amount extra to add to the radius to cater for hit detection outside the drawn point
pointHitDetectionRadius : 20,
//Boolean - Whether to show a stroke for datasets
datasetStroke : true,
//Number - Pixel width of dataset stroke
datasetStrokeWidth : 2,
//Boolean - Whether to fill the dataset with a colour
datasetFill : true,
//Boolean - Re-draw chart on page resize
responsive: true,
//String - A legend template
legendTemplate : "<ul class=\"<%=name.toLowerCase()%>-legend\"><% for (var i=0; i<datasets.length; i++){%><li><span style=\"background-color:<%=datasets[i].lineColor%>\"></span><%if(datasets[i].label){%><%=datasets[i].label%><%}%></li><%}%></ul>"
};
var lineData = {
labels: data,
datasets: [
{
pointHighlightStroke: "rgba(151,187,205,1)",
data: []
}
]
};
var getElement = document.getElementById("departuresChart2");
var ctx = getElement.getContext("2d");
$scope.myNewChart = new Chart(ctx).Line(lineData, lineOptions);
I am taking reference from http://www.chartjs.org/docs/#line-chart-introduction.
I want to hide only A'axis label.I have seen one link in stackoverflow Remove x-axis label/text in chart.js. But still I am not able to fixed. Thanks
You have to set scale.xLabels property of your chart (instance), to an empty array - [] (hides x-axis gridlines), or $scope.myNewChart.scale.xLabels.map(e => '') (shows x-axis gridlines), to hide x-axis labels.
Example
var lineOptions = {
//Boolean - Whether grid lines are shown across the chart
scaleShowGridLines: true,
//String - Colour of the grid lines
scaleGridLineColor: "rgba(0,0,0,.05)",
//Number - Width of the grid lines
scaleGridLineWidth: 1,
//Boolean - Whether the line is curved between points
bezierCurve: true,
//Number - Tension of the bezier curve between points
bezierCurveTension: 0.4,
//Boolean - Whether to show a dot for each point
pointDot: true,
//Number - Radius of each point dot in pixels
pointDotRadius: 4,
//Number - Pixel width of point dot stroke
pointDotStrokeWidth: 1,
//Number - amount extra to add to the radius to cater for hit detection outside the drawn point
pointHitDetectionRadius: 20,
//Boolean - Whether to show a stroke for datasets
datasetStroke: true,
//Number - Pixel width of dataset stroke
datasetStrokeWidth: 2,
//Boolean - Whether to fill the dataset with a colour
datasetFill: true,
//Boolean - Re-draw chart on page resize
responsive: true,
//String - A legend template
legendTemplate: "<ul class=\"<%=name.toLowerCase()%>-legend\"><% for (var i=0; i<datasets.length; i++){%><li><span style=\"background-color:<%=datasets[i].lineColor%>\"></span><%if(datasets[i].label){%><%=datasets[i].label%><%}%></li><%}%></ul>"
};
var lineData = {
labels: ["January", "February", "March", "April", "May", "June", "July"],
datasets: [{
label: "My Second dataset",
fillColor: "rgba(151,187,205,0.2)",
strokeColor: "rgba(151,187,205,1)",
pointColor: "rgba(151,187,205,1)",
data: [28, 48, 40, 19, 86, 27, 90]
}]
};
var getElement = document.getElementById("departuresChart2");
var ctx = getElement.getContext("2d");
myNewChart = new Chart(ctx).Line(lineData, lineOptions);
myNewChart.scale.xLabels = []; //or set -> myNewChart.scale.xLabels.map(e => '');
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/1.0.2/Chart.min.js"></script>
<canvas id="departuresChart2"></canvas>

C# MVC5 View dynamically filled Chart.js dont show up

I am trying to implement a chart of the chart.js library into my view. However, i am not able to display the chart as desired.
The particular part in my razor view:
<div class="col-md-8">
<p class="text-center">
<strong>Energy Consumption and Production: 1 Jan, 2016 - 30 Jul, 2016</strong>
</p>
<div class="chart-responsive">
<canvas id="trendChart" width="800" height="400"></canvas>
</div> #*/.chart-responsive*#
My Javascript code regarding the line chart:
$(function () {
var datachart = {
labels: [],
datasets: [
{
label: "Consumption",
backgroundColor: "rgba(215,220,67,0.3)",
borderColor: "rgba(220,220,220,0.7)",
borderWidth: 1,
hoverBackgroundColor: "rgba(220,220,220,1)",
hoverBorderColor: "rgba(220,220,220,0.5)",
data: []
},
{
label: "Production",
backgroundColor: "rgba(90,193,208,0.3)",
borderColor: "rgba(151,187,205,0.7)",
borderWidth: 1,
hoverBackgroundColor: "rgba(151,187,205,1)",
hoverBorderColor: "rgba(151,187,205,0.5)",
data: []
}
]
};
var trendChartOptions = {
//Boolean - If we should show the scale at all
showScale: true,
//Boolean - Whether grid lines are shown across the chart
scaleShowGridLines: false,
//String - Colour of the grid lines
scaleGridLineColor: "rgba(0,0,0,.05)",
//Number - Width of the grid lines
scaleGridLineWidth: 1,
//Boolean - Whether to show horizontal lines (except X axis)
scaleShowHorizontalLines: true,
//Boolean - Whether to show vertical lines (except Y axis)
scaleShowVerticalLines: true,
//Boolean - Whether the line is curved between points
bezierCurve: true,
//Number - Tension of the bezier curve between points
bezierCurveTension: 0.3,
//Boolean - Whether to show a dot for each point
pointDot: false,
//Number - Radius of each point dot in pixels
pointDotRadius: 4,
//Number - Pixel width of point dot stroke
pointDotStrokeWidth: 1,
//Number - amount extra to add to the radius to cater for hit detection outside the drawn point
pointHitDetectionRadius: 20,
//Boolean - Whether to show a stroke for datasets
datasetStroke: true,
//Number - Pixel width of dataset stroke
datasetStrokeWidth: 2,
//Boolean - Whether to fill the dataset with a color
datasetFill: true,
//String - A legend template
legendTemplate: "<ul class=\"<%=name.toLowerCase()%>-legend\"><% for (var i=0; i<datasets.length; i++){%><li><span style=\"background-color:<%=datasets[i].lineColor%>\"></span><%=datasets[i].label%></li><%}%></ul>",
//Boolean - whether to maintain the starting aspect ratio or not when responsive, if set to false, will take up entire container
maintainAspectRatio: false,
multiTooltipTemplate: "<%= datasetLabel %> - <%= value %>",
//Boolean - whether to make the chart responsive to window resizing
responsive: true
};
$.getJSON("/AdminLte/GetData", function (data) {
$.each(data, function (i, item) {
datachart.labels.push(item._DATE);
datachart.datasets[0].data.push(item.CONSUMPTION);
datachart.datasets[1].data.push(item.PRODUCTION);
})
});
var ctx = new Chart(document.getElementById("trendChart").getContext("2d")).Line(datachart, trendChartOptions);
});
And my controller method for dynamically filling the data:
public ContentResult GetData()
{
List<MeterDataTrendViewModel> meterDataTrend = new List<MeterDataTrendViewModel>();
var result =
from s in db.MeterDatas.ToList()
group s by new { s._DATE } into g
select new
{
read_date = g.Key._DATE,
CONSUMPTION = g.Sum(x => Convert.ToInt64(x.CONSUMPTION)),
PRODUCTION = g.Sum(x => Convert.ToInt64(x.PRODUCTION))
};
foreach(var res in result)
{
MeterDataTrendViewModel mdv = new MeterDataTrendViewModel();
mdv._DATE = res.read_date;
mdv.CONSUMPTION = res.CONSUMPTION.ToString();
mdv.PRODUCTION = res.PRODUCTION.ToString();
meterDataTrend.Add(mdv);
}
return Content(JsonConvert.SerializeObject(meterDataTrend), "application/json");
}
I`ve already debugged my js code and the data and labels array is filled correctly therefore my controller action is called. But there is only one datetime string displayed vertically so i guess it´s maybe aligned to the y-axis?
I can also fill the chart with static data and it´s displayed correctly. I cant figure out why my dynamic data isn´t displayed the right way.
I've managed to resolve this problem on my own with the following modifications.
$.getJSON("/AdminLte/GetData", function (data) {
$.each(data, function (i, item) {
chartlabels[i] = item._DATE;
cons[i] = item.CONSUMPTION;
prod[i] = item.PRODUCTION;
})
var ctx = new Chart(document.getElementById("trendChart").getContext("2d")).Line(datachart, trendChartOptions);
});
});

How to use values coming in ws.onmessage event into another function

I am working on web socket related project.In following snippet I am getting the data coming from the server. I want to use the this data(in str variable) into another function. Kindly suggest any solution. Thank you in advance.
/*ON RECEIVING MESSAGES VIA WEBSOCKET FROM THE SERVER***/
ws.onmessage = function (event) {
var mySpan = document.getElementById("messageGoesHere");
var mySpan2 = document.getElementById("messageGoesHere2");
var str = event.data;
var array = str.split('|');
mySpan.innerHTML = parseInt(array[2])
mySpan2.innerHTML = parseInt(array[3]);
};
$(function () {
//Here I want to print the data
// and I can easily use this data to my chart
var areaChartData = {
//labels: ["January", "February", "March", "April", "May", "June", "July"],
labels: ["10", "20", "30", "40", "50", "60", "100"],
datasets: [{
label: "Digital Goods",
fillColor: "rgba(60,141,188,0.9)",
strokeColor: "rgba(60,141,188,0.8)",
pointColor: "#3b8bba",
pointStrokeColor: "rgba(60,141,188,1)",
pointHighlightFill: "#fff",
pointHighlightStroke: "rgba(60,141,188,1)",
data: [28, 48, 40, 19, 86, 27, 90]
}]
};
var areaChartOptions = {
showScale: true,
scaleShowGridLines: false,
//String - Colour of the grid lines
scaleGridLineColor: "rgba(0,0,0,.05)",
//Number - Width of the grid lines
scaleGridLineWidth: 1,
//Boolean - Whether to show horizontal lines (except X axis)
scaleShowHorizontalLines: true,
//Boolean - Whether to show vertical lines (except Y axis)
scaleShowVerticalLines: true,
//Boolean - Whether the line is curved between points
bezierCurve: true,
//Number - Tension of the bezier curve between points
bezierCurveTension: 0.3,
//Boolean - Whether to show a dot for each point
pointDot: false,
//Number - Radius of each point dot in pixels
pointDotRadius: 4,
//Number - Pixel width of point dot stroke
pointDotStrokeWidth: 1,
//Number - amount extra to add to the radius to cater for hit detection outside the drawn point
pointHitDetectionRadius: 20,
//Boolean - Whether to show a stroke for datasets
datasetStroke: true,
//Number - Pixel width of dataset stroke
datasetStrokeWidth: 2,
//Boolean - Whether to fill the dataset with a color
datasetFill: true,
//String - A legend template
legendTemplate: "<ul class=\"<%=name.toLowerCase()%>-legend\"><% for (var i=0; i<datasets.length; i++){%><li><span style=\"background-color:<%=datasets[i].lineColor%>\"></span><%if(datasets[i].label){%><%=datasets[i].label%><%}%></li><%}%></ul>",
//Boolean - whether to maintain the starting aspect ratio or not when responsive, if set to false, will take up entire container
maintainAspectRatio: true,
//Boolean - whether to make the chart responsive to window resizing
responsive: true
};
//-------------
//- LINE CHART -
//--------------
var lineChartCanvas = $("#lineChart").get(0).getContext("2d");
alert(lineChartCanvas);
var lineChart = new Chart(lineChartCanvas);
var lineChartOptions = areaChartOptions;
lineChartOptions.datasetFill = false;
lineChart.Line(areaChartData, lineChartOptions);
});
Do you mean something like this?
var mySpan = document.getElementById("messageGoesHere");
var mySpan2 = document.getElementById("messageGoesHere2");
function myCallback(event) {
var str = event.data;
var array = str.split('|');
mySpan.innerHTML = parseInt(array[2])
mySpan2.innerHTML = parseInt(array[3]);
};
/*ON RECEIVING MESSAGES VIA WEBSOCKET FROM THE SERVER***/
ws.onmessage = myCallback;

add value to Line chart.js

I work chartjs for show Line Chart. Now, I need to add title/value for each value mouse over In Line charts.
Js:
var data = {
labels: ["February", "March", "April", "May", "June", "July"],
datasets: [{
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,1)",
data: [ 59, 90, 81, 56, 55, 40]
}, {
fillColor: "rgba(151,187,205,0.5)",
strokeColor: "rgba(151,187,205,1)",
data: [ 48, 40, 59, -100, 127, 100]
}]
}
var options = {animation :true};
//Get the context of the canvas element we want to select
var c = $('#daily-chart');
var ct = c.get(0).getContext('2d');
var ctx = document.getElementById("daily-chart").getContext("2d");
/*************************************************************************/
//Run function when window resizes
$(window).resize(respondCanvas);
function respondCanvas() {
c.attr('width', jQuery("#daily").width());
c.attr('height', jQuery("#daily").height());
//Call a function to redraw other content (texts, images etc)
myNewChart = new Chart(ct).Line(data, options);
}
//Initial call
respondCanvas();
How Do can I add title/value for each value/month?
DEMO: jsFiddle
If you use the latest version of chart.js there is a new update allow you to show a tooltip with value/title. http://www.chartjs.org/docs/
There is several options to custom the tooltip on mouseover
// Boolean - Determines whether to draw tooltips on the canvas or not
showTooltips: true,
// Array - Array of string names to attach tooltip events
tooltipEvents: ["mousemove", "touchstart", "touchmove"],
// String - Tooltip background colour
tooltipFillColor: "rgba(0,0,0,0.8)",
// String - Tooltip label font declaration for the scale label
tooltipFontFamily: "'Helvetica Neue', 'Helvetica', 'Arial', sans-serif",
// Number - Tooltip label font size in pixels
tooltipFontSize: 14,
// String - Tooltip font weight style
tooltipFontStyle: "normal",
// String - Tooltip label font colour
tooltipFontColor: "#fff",
// String - Tooltip title font declaration for the scale label
tooltipTitleFontFamily: "'Helvetica Neue', 'Helvetica', 'Arial', sans-serif",
// Number - Tooltip title font size in pixels
tooltipTitleFontSize: 14,
// String - Tooltip title font weight style
tooltipTitleFontStyle: "bold",
// String - Tooltip title font colour
tooltipTitleFontColor: "#fff",
// Number - pixel width of padding around tooltip text
tooltipYPadding: 6,
// Number - pixel width of padding around tooltip text
tooltipXPadding: 6,
// Number - Size of the caret on the tooltip
tooltipCaretSize: 8,
// Number - Pixel radius of the tooltip border
tooltipCornerRadius: 6,
// Number - Pixel offset from point x to tooltip edge
tooltipXOffset: 10,
// String - Template string for single tooltips
tooltipTemplate: "<%if (label){%><%=label%>: <%}%><%= value %>",
I agree with #jbr
I have just updated the chart.min.js file link in your fiddle and you existing code shows tooltip on hover the chart..
check the updated fiddle

Categories