Abstract chart factory and chart classes that separate the contract and implementation. jqPlot specific implementations of these classes.

This commit is contained in:
Madhura Jayaratne 2013-01-14 20:11:55 +05:30
parent 053d6c2ce0
commit 2fcfcf883b

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js/chart.js Normal file
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/**
* Chart type enumerations
*/
var ChartType = {
LINE : 'line',
AREA : 'area',
BAR : 'bar',
COLUMN : 'column',
PIE : 'pie'
};
/**
* Abstract chart factory which defines the contract for chart factories
*/
var ChartFactory = function() {
};
ChartFactory.prototype = {
createChart : function(type, options) {
throw new Error("createChart must be implemented by a subclass");
}
};
/**
* Abstract chart which defines the contract for charts
*
* @param elementId
* id of the div element the chart is drawn in
*/
var Chart = function(elementId) {
this.elementId = elementId;
};
Chart.prototype = {
draw : function(data, options) {
throw new Error("draw must be implemented by a subclass");
},
redraw : function(options) {
throw new Error("redraw must be implemented by a subclass");
},
destroy : function() {
throw new Error("destroy must be implemented by a subclass");
}
};
/**
* Abstract representation of charts that operates on DataTable where,<br />
* <ul>
* <li>First column provides index to the data.</li>
* <li>Each subsequent columns are of type
* <code>ColumnType.NUMBER<code> and represents a data series.</li>
* </ul>
* Line chart, area chart, bar chart, column chart are typical examples.
*
* @param elementId
* id of the div element the chart is drawn in
*/
var BaseChart = function(elementId) {
Chart.call(this, elementId);
};
BaseChart.prototype = new Chart();
BaseChart.prototype.constructor = BaseChart;
BaseChart.prototype.validateColumns = function(dataTable) {
var columns = dataTable.getColumns();
if (columns.length < 2) {
throw new Error("Minimum of two columns are required for this chart");
}
for ( var i = 1; i < columns.length; i++) {
if (columns[i].type != ColumnType.NUMBER) {
throw new Error("Column " + (i + 1) + " should be of type 'Number'");
}
}
return true;
};
/**
* Abstract pie chart
*
* @param elementId
* id of the div element the chart is drawn in
*/
var PieChart = function(elementId) {
BaseChart.call(this, elementId);
};
PieChart.prototype = new BaseChart();
PieChart.prototype.constructor = PieChart;
PieChart.prototype.validateColumns = function(dataTable) {
var columns = dataTable.getColumns();
if (columns.length > 2) {
throw new Error("Pie charts can draw only one series");
}
return BaseChart.prototype.validateColumns.call(this, dataTable);
};
/**
* The data table contains column information and data for the chart.
*/
var DataTable = function() {
var columns = [];
var data;
this.addColumn = function(type, name) {
columns.push({
'type' : type,
'name' : name
});
};
this.getColumns = function() {
return columns;
};
this.setData = function(rows) {
data = rows;
fillMissingValues();
};
this.getData = function() {
return data;
};
var fillMissingValues = function() {
if (columns.length == 0) {
throw new Error("Set columns first");
}
var row, column;
for ( var i = 0; i < data.length; i++) {
row = data[i];
if (row.length > columns.length) {
row.splice(columns.length - 1, row.length - columns.length);
} else if (row.length < columns.length) {
for ( var j = row.length; j < columns.length; j++) {
row.push(null);
}
}
}
};
};
/**
* Column type enumeration
*/
var ColumnType = {
STRING : 'string',
NUMBER : 'number',
BOOLEAN : 'boolean',
DATE : 'date'
};
/*******************************************************************************
* JQPlot specifc code
******************************************************************************/
/**
* Chart factory that returns JQPlotCharts
*/
var JQPlotChartFactory = function() {
};
JQPlotChartFactory.prototype = new ChartFactory();
JQPlotChartFactory.prototype.createChart = function(type, elementId) {
var chart;
switch (type) {
case ChartType.LINE:
chart = new JQPlotLineChart(elementId);
break;
case ChartType.AREA:
chart = new JQPlotAreaChart(elementId);
break;
case ChartType.BAR:
chart = new JQPlotBarChart(elementId);
break;
case ChartType.COLUMN:
chart = new JQPlotColumnChart(elementId);
break;
case ChartType.PIE:
chart = new JQPlotPieChart(elementId);
break;
}
return chart;
};
/**
* Abstract JQplot chart
*
* @param elementId
* id of the div element the chart is drawn in
*/
var JQPlotChart = function(elementId) {
Chart.call(this, elementId);
this.plot;
this.validator;
};
JQPlotChart.prototype = new Chart();
JQPlotChart.prototype.constructor = JQPlotChart;
JQPlotChart.prototype.draw = function(data, options) {
if (this.validator.validateColumns(data)) {
this.plot = $.jqplot(this.elementId, this.prepareData(data), this
.populateOptions(data, options));
}
};
JQPlotChart.prototype.destroy = function() {
if (this.plot != null) {
this.plot.destroy();
}
};
JQPlotChart.prototype.redraw = function(options) {
if (this.plot != null) {
this.plot.replot(options);
}
};
JQPlotChart.prototype.populateOptions = function(dataTable, options) {
throw new Error("populateOptions must be implemented by a subclass");
};
JQPlotChart.prototype.prepareData = function(dataTable) {
throw new Error("prepareData must be implemented by a subclass");
};
/**
* JQPlot line chart
*
* @param elementId
* id of the div element the chart is drawn in
*/
var JQPlotLineChart = function(elementId) {
JQPlotChart.call(this, elementId);
this.validator = BaseChart.prototype;
};
JQPlotLineChart.prototype = new JQPlotChart();
JQPlotLineChart.prototype.constructor = JQPlotLineChart;
JQPlotLineChart.prototype.populateOptions = function(dataTable, options) {
var columns = dataTable.getColumns();
if (options.series == null) {
options.series = [];
}
if (options.series.length == 0) {
for ( var i = 1; i < columns.length; i++) {
options.series.push({
label : columns[i].name.toString()
});
}
}
if (options.axes == null) {
options.axes = {};
}
if (options.axes.xaxis == null) {
options.axes.xaxis = {};
}
if (options.axes.xaxis.label == null) {
options.axes.xaxis.label = columns[0].name;
}
if (options.axes.xaxis.renderer == null) {
options.axes.xaxis.renderer = $.jqplot.CategoryAxisRenderer;
}
if (options.axes.xaxis.labelRenderer == null) {
options.axes.xaxis.labelRenderer = $.jqplot.CanvasAxisLabelRenderer;
}
if (options.axes.xaxis.ticks == null) {
options.axes.xaxis.ticks = [];
}
if (options.axes.xaxis.ticks.length == 0) {
var data = dataTable.getData();
for ( var i = 0; i < data.length; i++) {
options.axes.xaxis.ticks.push(data[i][0].toString());
}
}
if (options.axes.yaxis == null) {
options.axes.yaxis = {};
}
if (options.axes.yaxis.label == null) {
if (columns.length == 2) {
options.axes.yaxis.label = columns[1].name;
} else {
options.axes.yaxis.label = 'Values';
}
}
if (options.axes.yaxis.labelRenderer == null) {
options.axes.yaxis.labelRenderer = $.jqplot.CanvasAxisLabelRenderer;
}
return options;
};
JQPlotLineChart.prototype.prepareData = function(dataTable) {
var data = dataTable.getData(), row;
var retData = [], retRow;
for ( var i = 0; i < data.length; i++) {
row = data[i];
for ( var j = 1; j < row.length; j++) {
retRow = retData[j - 1];
if (retRow == null) {
retRow = [];
retData[j - 1] = retRow;
}
retRow.push(row[j]);
}
}
return retData;
};
/**
* JQPlot area chart
*
* @param elementId
* id of the div element the chart is drawn in
*/
var JQPlotAreaChart = function(elementId) {
JQPlotLineChart.call(this, elementId);
};
JQPlotAreaChart.prototype = new JQPlotLineChart();
JQPlotAreaChart.prototype.constructor = JQPlotAreaChart;
JQPlotAreaChart.prototype.populateOptions = function(dataTable, options) {
if (options.seriesDefaults == null) {
options.seriesDefaults = {};
}
options.seriesDefaults.fill = true;
return JQPlotLineChart.prototype.populateOptions.call(this, dataTable,
options);
};
/**
* JQPlot column chart
*
* @param elementId
* id of the div element the chart is drawn in
*/
var JQPlotColumnChart = function(elementId) {
JQPlotLineChart.call(this, elementId);
};
JQPlotColumnChart.prototype = new JQPlotLineChart();
JQPlotColumnChart.prototype.constructor = JQPlotColumnChart;
JQPlotColumnChart.prototype.populateOptions = function(dataTable, options) {
if (options.seriesDefaults == null) {
options.seriesDefaults = {
fillToZero : true
};
}
options.seriesDefaults.renderer = $.jqplot.BarRenderer;
return JQPlotLineChart.prototype.populateOptions.call(this, dataTable,
options);
};
/**
* JQPlot bar chart
*
* @param elementId
* id of the div element the chart is drawn in
*/
var JQPlotBarChart = function(elementId) {
JQPlotLineChart.call(this, elementId);
};
JQPlotBarChart.prototype = new JQPlotLineChart();
JQPlotBarChart.prototype.constructor = JQPlotBarChart;
JQPlotBarChart.prototype.populateOptions = function(dataTable, options) {
if (options.seriesDefaults == null) {
options.seriesDefaults = {
fillToZero : true
};
}
options.seriesDefaults.renderer = $.jqplot.BarRenderer;
if (options.seriesDefaults.rendererOptions == null) {
options.seriesDefaults.rendererOptions = {};
}
options.seriesDefaults.rendererOptions.barDirection = 'horizontal';
var columns = dataTable.getColumns();
if (options.series == null) {
options.series = [];
}
if (options.series.length == 0) {
for ( var i = 1; i < columns.length; i++) {
options.series.push({
label : columns[i].name.toString()
});
}
}
if (options.axes == null) {
options.axes = {};
}
if (options.axes.yaxis == null) {
options.axes.yaxis = {};
}
if (options.axes.yaxis.label == null) {
options.axes.yaxis.label = columns[0].name;
}
if (options.axes.yaxis.renderer == null) {
options.axes.yaxis.renderer = $.jqplot.CategoryAxisRenderer;
}
if (options.axes.yaxis.labelRenderer == null) {
options.axes.yaxis.labelRenderer = $.jqplot.CanvasAxisLabelRenderer;
}
if (options.axes.yaxis.ticks == null) {
options.axes.yaxis.ticks = [];
}
if (options.axes.yaxis.ticks.length == 0) {
var data = dataTable.getData();
for ( var i = 0; i < data.length; i++) {
options.axes.yaxis.ticks.push(data[i][0].toString());
}
}
if (options.axes.xaxis == null) {
options.axes.xaxis = {};
}
if (options.axes.xaxis.label == null) {
if (columns.length == 2) {
options.axes.xaxis.label = columns[1].name;
} else {
options.axes.xaxis.label = 'Values';
}
}
if (options.axes.xaxis.labelRenderer == null) {
options.axes.xaxis.labelRenderer = $.jqplot.CanvasAxisLabelRenderer;
}
return options;
};
/**
* JQPlot pie chart
*
* @param elementId
* id of the div element the chart is drawn in
*/
var JQPlotPieChart = function(elementId) {
JQPlotChart.call(this, elementId);
this.validator = PieChart.prototype;
};
JQPlotPieChart.prototype = new JQPlotChart();
JQPlotPieChart.prototype.constructor = JQPlotPieChart;
JQPlotPieChart.prototype.populateOptions = function(dataTable, options) {
if (options.seriesDefaults == null) {
options.seriesDefaults = {};
}
options.seriesDefaults.renderer = $.jqplot.PieRenderer;
return options;
};
JQPlotPieChart.prototype.prepareData = function(dataTable) {
var data = dataTable.getData(), row;
var retData = [];
for ( var i = 0; i < data.length; i++) {
row = data[i];
retData.push([ row[0], row[1] ]);
}
return [ retData ];
};