Added showXLabels for Line and Bar charts.

It enables controlling the number of labels shown on x axis. Really helpful in case there are huge number of labels.

Chart.Core.js has been edited  so, showXLabels option is available to any other chart as well if anybody wants to extend this feature.

docs/01-Line-Chart.md

@@ -57,6 +57,10 @@ These are the customisation options specific to Line charts. These options are m
 ```javascript
 {
 
+	//Boolean or Number - Number of labels to be shown on X-Axis. false: no label displayed, true: all labels
+	displayed, 10: only 10 labels displayed
+	showXLabels: 10,
+
 	///Boolean - Whether grid lines are shown across the chart
 	scaleShowGridLines : true,
 

docs/02-Bar-Chart.md

@@ -53,6 +53,10 @@ These are the customisation options specific to Bar charts. These options are me
 
 ```javascript
 {
+	//Boolean or Number - Number of labels to be shown on X-Axis. false: no label displayed, true: all labels
+	displayed, 10: only 10 labels displayed
+	showXLabels: 10,
+
 	//Boolean - Whether the scale should start at zero, or an order of magnitude down from the lowest value
 	scaleBeginAtZero : true,
 

src/Chart.Bar.js

@@ -209,6 +209,7 @@
 					helpers.extend(this, updatedRanges);
 				},
 				xLabels : labels,
+				showXLabels: (this.options.showXLabels) ? this.options.showXLabels : true,
 				font : helpers.fontString(this.options.scaleFontSize, this.options.scaleFontStyle, this.options.scaleFontFamily),
 				lineWidth : this.options.scaleLineWidth,
 				lineColor : this.options.scaleLineColor,

src/Chart.Core.js

@@ -68,6 +68,9 @@
 			// Boolean - Whether to show labels on the scale
 			scaleShowLabels: true,
 
+			// Boolean or a positive integer denoting number of labels to be shown on x axis
+			showXLabels: true,
+
 			// Interpolated JS string - can access value
 			scaleLabel: "<%=value%>",
 
@@ -1644,6 +1647,9 @@
 
 				},this);
 
+				// if showXLabels is a number then divide and determine how many xLabels to skip before showing next label
+				// else, if showXLabels is true, print all labels, else never print
+				this.xLabelsSkipper = isNumber(this.showXLabels) ? Math.ceil(this.xLabels.length/this.showXLabels) : (this.showXLabels === true) ? 1 : this.xLabels.length+1;
 				each(this.xLabels,function(label,index){
 					var xPos = this.calculateX(index) + aliasPixel(this.lineWidth),
 						// Check to see if line/bar here and decide where to place the line
@@ -1695,7 +1701,9 @@
 					ctx.font = this.font;
 					ctx.textAlign = (isRotated) ? "right" : "center";
 					ctx.textBaseline = (isRotated) ? "middle" : "top";
-					ctx.fillText(label, 0, 0);
+					if(index % this.xLabelsSkipper === 0) {
+						ctx.fillText(label, 0, 0);
+					}
 					ctx.restore();
 				},this);
 

src/Chart.Line.js

@@ -193,6 +193,7 @@
 					helpers.extend(this, updatedRanges);
 				},
 				xLabels : labels,
+				showXLabels: (this.options.showXLabels) ? this.options.showXLabels : true,
 				font : helpers.fontString(this.options.scaleFontSize, this.options.scaleFontStyle, this.options.scaleFontFamily),
 				lineWidth : this.options.scaleLineWidth,
 				lineColor : this.options.scaleLineColor,