Add decimal option for formatting axis labels

lib/timeline/DataStep.js

@@ -178,19 +178,59 @@ DataStep.prototype.previous = function() {
  * Get the current datetime
  * @return {String}  current The current date
  */
-DataStep.prototype.getCurrent = function() {
+DataStep.prototype.getCurrent = function(decimals) {
   var toPrecision = '' + Number(this.current).toPrecision(5);
-  if (toPrecision.indexOf(",") != -1 || toPrecision.indexOf(".") != -1) {
-    for (var i = toPrecision.length-1; i > 0; i--) {
-      if (toPrecision[i] == "0") {
-        toPrecision = toPrecision.slice(0,i);
+  // If decimals is specified, then limit or extend the string as required
+  if(decimals !== undefined && !isNaN(Number(decimals))) {
+    // If string includes exponent, then we need to add it to the end
+    var exp = "";
+    var index = toPrecision.indexOf("e");
+    if(index != -1) {
+      // Get the exponent
+      exp = toPrecision.slice(index);
+      // Remove the exponent in case we need to zero-extend
+      toPrecision = toPrecision.slice(0, index);
+    }
+    index = Math.max(toPrecision.indexOf(","), toPrecision.indexOf("."));
+    if(index === -1) {
+      // No decimal found - if we want decimals, then we need to add it
+      if(decimals !== 0) {
+        toPrecision += '.';
       }
-      else if (toPrecision[i] == "." || toPrecision[i] == ",") {
-        toPrecision = toPrecision.slice(0,i);
-        break;
+      // Calculate how long the string should be
+      index = toPrecision.length + decimals;
+    }
+    else if(decimals !== 0) {
+      // Calculate how long the string should be - accounting for the decimal place
+      index += decimals + 1;
+    }
+    if(index > toPrecision.length) {
+      // We need to add zeros!
+      for(var cnt = index - toPrecision.length; cnt > 0; cnt--) {
+        toPrecision += '0';
       }
-      else{
-        break;
+    }
+    else {
+      // we need to remove characters
+      toPrecision = toPrecision.slice(0, index);
+    }
+    // Add the exponent if there is one
+    toPrecision += exp;
+  }
+  else {
+    if (toPrecision.indexOf(",") != -1 || toPrecision.indexOf(".") != -1) {
+      // If no decimal is specified, and there are decimal places, remove trailing zeros
+      for (var i = toPrecision.length - 1; i > 0; i--) {
+        if (toPrecision[i] == "0") {
+          toPrecision = toPrecision.slice(0, i);
+        }
+        else if (toPrecision[i] == "." || toPrecision[i] == ",") {
+          toPrecision = toPrecision.slice(0, i);
+          break;
+        }
+        else {
+          break;
+        }
       }
     }
   }

lib/timeline/component/DataAxis.js

@@ -30,6 +30,10 @@ function DataAxis (body, options, svg, linegraphOptions) {
     customRange: {
       left: {min:undefined, max:undefined},
       right: {min:undefined, max:undefined}
+    },
+    format: {
+      left: {decimals: undefined},
+      right: {decimals: undefined}
     }
   };
 
@@ -108,7 +112,8 @@ DataAxis.prototype.setOptions = function (options) {
       'iconWidth',
       'width',
       'visible',
-      'customRange'
+      'customRange',
+      'format'
     ];
     util.selectiveExtend(fields, this.options, options);
 
@@ -326,6 +331,12 @@ DataAxis.prototype._redrawLabels = function () {
   // do not draw the first label
   var max = 1;
 
+  // Get the number of decimal places
+  var decimals;
+  if(this.options.format[orientation] !== undefined) {
+    decimals = this.options.format[orientation].decimals;
+  }
+
   this.maxLabelSize = 0;
   var y = 0;
   while (max < Math.round(amountOfSteps)) {
@@ -335,13 +346,13 @@ DataAxis.prototype._redrawLabels = function () {
     var isMajor = step.isMajor();
 
     if (this.options['showMinorLabels'] && isMajor == false || this.master == false && this.options['showMinorLabels'] == true) {
-      this._redrawLabel(y - 2, step.getCurrent(), orientation, 'yAxis minor', this.props.minorCharHeight);
+      this._redrawLabel(y - 2, step.getCurrent(decimals), orientation, 'yAxis minor', this.props.minorCharHeight);
     }
 
     if (isMajor && this.options['showMajorLabels'] && this.master == true ||
         this.options['showMinorLabels'] == false && this.master == false && isMajor == true) {
       if (y >= 0) {
-        this._redrawLabel(y - 2, step.getCurrent(), orientation, 'yAxis major', this.props.majorCharHeight);
+        this._redrawLabel(y - 2, step.getCurrent(decimals), orientation, 'yAxis major', this.props.majorCharHeight);
       }
       this._redrawLine(y, orientation, 'grid horizontal major', this.options.majorLinesOffset, this.props.majorLineWidth);
     }