ChartCanvas
Generates simple charts in canvas with client side JS or Node.JS with a responsive design. ChartCanvas has the following functions:
- Cartesian charts
- Pie charts
- Multi axes charts
- Support for Node.JS
- Responsive design
Before you read this doc. I recommend see the example HTML file in doc directory.
Basic use
To use ChartCanvas class you must be include in your HTML: jQuery, ChartCanvas.js file, and chart types that you want to use in your project:
<!-- You must include this code in HEAD -->
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="ChartCanvas.js"></script>
<!-- Now you must include the chart type you need-->
<script src="types/ChartCanvas_axes.js"></script>
<script src="types/ChartCanvas_pie.js"></script>
</head>
Then we must create one or more canvas elements with the attribute 'class = "ChartCanvas"'. For example:
<canvas id="canvas" width="805" height="315" class="ChartCanvas">
Fallback content
</canvas>
Then we create an array of data that need to display in the graph, with the structure: array [[timestam1, value1], [timestam2, value2]] in the case of Cartesian graphs or array [[index1, value1] , [index2, value2]] in the case of "pie charts".
Once we have the array, we have to create the JSON string to serve as a setting for our graph. We will generate a graph of type "pie chart" as an example:
var dataArrayX = new Array();
var dataBar11_X = [
[1, 2],
[2, 1],
[3, 1],
[4, 6],
[5, 1],
[6, 2]];
dataArrayX.push(dataBar11_X); //Each group of data to display in the chart is inserted into the main array. In this there is only one group becouse this is a Pie Chart
var jsonSettingsX = { "data" : dataArrayX,
"labels" : ['Pepe', 'Juan', 'Manolo', 'Ana', 'Eustaquio', 'Robustiana'],
"graphTypes" : ["donut"]
};
var canvas = $.extend(new ChartCanvas($("#canvas")[0], jsonSettingsX), new ChartCanvas_pie(jsonSettingsX));
$("#canvas").data('ChartCanvas', canvas);
$("#canvas").data('ChartCanvas').render();
The result:
If you look at the code above, we see that "ChartCanvas" extends in this case "ChartCanvas_pie" if it were a Cartesian graph extend "ChartCanvas_axes".
JSON Configuration
You can set the following vars with the configuration text in JSON:
| Var | Extension | Description |
| bgColor | axes | [OPTIONAL. Transparent BY DEFAULT] Background color - {'bgColor' : '#ffffff'} //The values should be hex. |
| cellWidth | axes | [OPTIONAL] Width for each cell - {'cellWidth': value} |
| colors | ALL | [OPTIONAL] Colors for each group un chart - {'colors' : ['#42d316', '#457cbf', '#FF0000']} // Hex. values |
| data | ALL | [MANDATORY] Chart data - { 'data' : arrayData } |
| graphTypes | axes, pie | [OPTIONAL] Chart type as the extended class. They can merge two types superimposed on one canvas - {'graphTypes': ['type1', 'type2' ...]} |
| labels | ALL | [OPTIONAL] Labels for each group of graphic value. For pie charts each record is read as a group - {'labels': ['value1', 'value2' ...]} |
| multiYAxis | axes | [OPTIONAL] Boolean true / false. Tell whether each group will have different Y-axes values (true) or share the same (false) - {'multiYAxis': value} |
| precision | ALL | [OPTIONAL. "day" BY DEFAULT] Minimum unit of time in a Cartesian graph - {'precision': value} / / Possible values are: millisecond, second, minute, hour, day, month, year |
Available extensions
ChartCanvas_axes
Cartesian charts.
- graphTypes: lines, linesFill, linesPoints, steps, stepsFill, bars, points
ChartCanvas_pie
Pie charts.
- graphTypes: donut, pie
Examples
Sets of values in a cartesian chart.
Here is the code:
var dataArray = new Array();
var dataBar11_0 = [
[1338501600000, 2]
, [1338933600000, 1]
, [1339106400000, 1]
, [1339279200000, 6]
, [1340488800000, 1]
, [1341093600000, 2]
];
dataArray.push(dataBar11_0);
var dataBar11_1 = [
[1338588000000, 1]
, [1338847200000, 1]
, [1339279200000, 4]
, [1339365600000, 1]
, [1339538400000, 1]
, [1339624800000, 1]
, [1339711200000, 6]
, [1340316000000, 3]
, [1340402400000, 1]
, [1340488800000, 2]
, [1341007200000, 1]
, [1341093600000, 1]
];
dataArray.push(dataBar11_1);
var dataBar11_2 = [
[1338588000000, 3]
, [1338847200000, 10]
, [1339279200000, 8]
, [1339365600000, 2]
];
dataArray.push(dataBar11_2);
var jsonSettings = { "data" : dataArray,
"precision" : "day",
"graphTypes" : ["points", "linesFill"],
"labels" : ['Grafica 1', 'Otra grafica mas', 'Y otra']
};
var canvas = $.extend(new ChartCanvas($("#canvas")[0], jsonSettings), new ChartCanvas_axes(jsonSettings));
$("#canvas").data('ChartCanvas', canvas);
$("#canvas").data('ChartCanvas').render();
Using ChartCanvas with Node.JS
We can use ChartCanvas as a Node.JS module. Here is an example for convert a canvas into a PNG.
To install the necessary modules we move into the directory where you saved the ChartCanvas folder and run:
npm install canvas #Allow us to convert a canvas to PNG
npm install jsdom #Allows the use of JQuery on server
And here the code:
var Jsdom = require('jsdom');
var ChartCanvas = require('./ChartCanvas/ChartCanvas.js');
var Extend = require('./extendClasses.js');
var Canvas = require('canvas')
, fs = require('fs');
//Chart data------------------------------
dataArray.push(dataBar11_1);
var dataBar11_2 = [
[1338588000000, 3]
, [1338847200000, 10]
, [1339279200000, 8]
, [1339365600000, 2]
];
dataArray.push(dataBar11_2);
var jsonSettings = { "data" : dataArray,
"precision" : "day",
"graphTypes" : ["points", "linesFill"],
"labels" : ['Grafica 1', 'Otra grafica mas', 'Y otra']
};
//--------------------------
Jsdom.env({
html: '',
scripts: [
'http://code.jquery.com/jquery-1.5.min.js'
]
}, function (err, window) {
var $ = window.jQuery;
var canvas = new Canvas(800, 300);//Width and height
var parent = new ChartCanvas(canvas, jsonSettings);
//For Pie Chart
var ChartCanvas_pie = require('./ChartCanvas/types/ChartCanvas_pie.js');
var child = new ChartCanvas_pie(jsonSettings);
/* //For cartesian graph
var ChartCanvas_axes = require('./ChartCanvas/types/ChartCanvas_axes.js');
var child = new ChartCanvas_axes(jsonSettings);
*/
var objCanvas = Extend.extend(parent, child);
objCanvas.render();
Canvas.ctx = objCanvas.ctx;
var out = fs.createWriteStream(__dirname + 'myPNG.png')
, stream = canvas.createPNGStream();
stream.on('data', function(chunk){
out.write(chunk);
});
});
How to install ChartCanvas on Symfony2
- You must modify composer.json file with the following code:
...
"repositories": [
{
"type": "package",
"package": {
"name": "jvcalderon/ChartCanvas",
"version": "1.1.5",
"dist": {
"url": "https://github.com/jvcalderon/ChartCanvas/archive/1.1.5.zip",
"type": "zip"
}
}
}
],
...
"require": {
...
"jvcalderon/ChartCanvas": "1.1.*"
},
- Now you must update the vendors:
composer update
That's all!
You can include the scripts in your Twig template with Assetic:
{% javascripts '%kernel.root_dir%/../vendor/jvcalderon/ChartCanvas/ChartCanvas.js' '%kernel.root_dir%/../vendor/jvcalderon/ChartCanvas/types/ChartCanvas_axes.js' '%kernel.root_dir%/../vendor/jvcalderon/ChartCanvas/types/ChartCanvas_pie.js' %} <script type="text/javascript" charset="utf-8" src="{{ asset_url }}"></script>{% endjavascripts %}