Simplifies using Chart.js in Rails views.
This gem includes Chart.js v2.9.4.
Add this line to your application's Gemfile:
gem 'chartjs-ror', git: 'https://github.com/robot-c0der/chartjs-ror'
And then execute:
$ bundle
There are two builds of Chart.js: with or without Moment.js.
Choose the appropriate one in your javascript manifest:
-
Without Moment.js:
//= require Chart.min
-
With Moment.js:
//= require Chart.bundle.min
Please note Chart.js no longer supports IE8 and below.
Each chart type has a corresponding helper for your views. The helper methods take the same arguments as their Javascript counterparts. The options
are optional.
<%= line_chart data, options %>
<%= bar_chart data, options %>
<%= horizontal_bar_chart data, options %>
<%= radar_chart data, options %>
<%= polar_area_chart data, options %>
<%= pie_chart data, options %>
<%= doughnut_chart data, options %>
<%= bubble_chart data, options %>
<%= scatter_chart data, options %>
If you don't want these helpers – perhaps they clash with other methods in your views – add this initializer to your app:
# config/initializers/chartjs.rb
Chartjs.no_conflict!
Then you can use these helpers instead:
<%= chartjs_line_chart data, options %>
<%= chartjs_bar_chart data, options %>
<%= chartjs_horizontal_bar_chart data, options %>
<%= chartjs_radar_chart data, options %>
<%= chartjs_polar_area_chart data, options %>
<%= chartjs_pie_chart data, options %>
<%= chartjs_doughnut_chart data, options %>
<%= chartjs_bubble_chart data, options %>
<%= chartjs_scatter_chart data, options %>
For example, to render a line chart in Javascript:
var data = {
labels: ["January", "February", "March", "April", "May", "June", "July"],
datasets: [
{
label: "My First dataset",
backgroundColor: "rgba(220,220,220,0.2)",
borderColor: "rgba(220,220,220,1)",
data: [65, 59, 80, 81, 56, 55, 40]
},
{
label: "My Second dataset",
backgroundColor: "rgba(151,187,205,0.2)",
borderColor: "rgba(151,187,205,1)",
data: [28, 48, 40, 19, 86, 27, 90]
}
]
};
var options = { ... };
new Chart(ctx, {
type: 'Line',
data: data,
options: options
});
The Ruby equivalent is:
data = {
labels: ["January", "February", "March", "April", "May", "June", "July"],
datasets: [
{
label: "My First dataset",
backgroundColor: "rgba(220,220,220,0.2)",
borderColor: "rgba(220,220,220,1)",
data: [65, 59, 80, 81, 56, 55, 40]
},
{
label: "My Second dataset",
backgroundColor: "rgba(151,187,205,0.2)",
borderColor: "rgba(151,187,205,1)",
data: [28, 48, 40, 19, 86, 27, 90]
}
]
}
options = { ... }
<%= line_chart data, options %>
You can also use underscored symbols for keys, instead of the camelcase versions. They will be converted to their lower camelcase counterparts on output.
data = {
labels: ["January", "February", "March", "April", "May", "June", "July"],
datasets: [
{
label: "My First dataset",
background_color: "rgba(220,220,220,0.2)",
border_color: "rgba(220,220,220,1)",
data: [65, 59, 80, 81, 56, 55, 40]
},
{
label: "My Second dataset",
background_color: "rgba(151,187,205,0.2)",
border_color: "rgba(151,187,205,1)",
data: [28, 48, 40, 19, 86, 27, 90]
}
]
}
options = { ... }
<%= line_chart data, options %>
You can put anything in the options
hash that Chart.js recognises. To pass a JavaScript function as an option value, wrap it in quotation marks to make it a string.
You can also use these non-Chart.js settings:
:class
- class of the DOM canvas element - default ischart
.:id
- id of the DOM canvas element - default ischart-n
wheren
is the 0-based index of the chart on the page.:width
- width of the canvas in px - default is400
.:height
- height of the canvas in px - default is400
.
<canvas id="chart-0" class="chart" width=400 height=400></canvas>
<script type="text/javascript">
//<![CDATA[
(function() {
var initChart = function() {
var ctx = document.getElementById("chart-0");
var chart = new Chart(ctx, {
type: "Line",
data = { ... };
options = { ... };
});
};
if (typeof Chart !== "undefined" && Chart !== null) {
initChart();
}
else {
if (window.addEventListener) {
window.addEventListener("load", initChart, false);
}
else if (window.attachEvent) {
window.attachEvent("onload", initChart);
}
}
})();
//]]>
</script>
The Javascript is actually written out on a single line but you get the idea.
Copyright Andrew Stewart, AirBlade Software. Released under the MIT licence.